Research and analysis

RIFE 31, Radioactivity in Food and the Environment, 2025

Updated 29 October 2026

Foreword

The UK’s environmental regulators and food safety agencies are pleased to present the 31^st edition of the Radioactivity in Food and the Environment (RIFE) report.

Radioactive substances have many beneficial uses, including their use in medical diagnostics and therapies and in power generation. They are unlikely to be harmful if controlled in the right way. Regulation aims to ensure these benefits can be realised, whilst keeping people and the environment safe. This regulation is embedded into relevant legislation, such as the Environmental Authorisations (Scotland) Regulations 2018, Environmental Permitting Regulations (England and Wales) 2016 and the Radioactive Substances (Modification of Enactments) Regulations (Northern Ireland) 2018. The independent monitoring of radioactivity in food and the environment is an important part of the regulatory process and provides reassurance to members of the public.

RIFE 31 sets out the findings of the monitoring programmes of radioactivity in food and the environment carried out in 2025 throughout the UK. These monitoring programmes are undertaken by the Environment Agency, Food Standards Agency, Food Standards Scotland, Natural Resources Wales, Northern Ireland Environment Agency, and the Scottish Environment Protection Agency.

The monitoring results and subsequent assessments presented in this report demonstrate that the exposure of members of the public to radiation, resulting from authorised discharges of radioactive waste and direct radiation, near nuclear and selected non-nuclear sites remained below the legal limit (1millisievert) in 2025.

The monitoring results and subsequent assessments presented in this report demonstrate that the exposure of members of the public to radiation, resulting from authorised discharges of radioactive waste and direct radiation, near nuclear and selected non-nuclear sites remained below the legal limit (1 milliSeivert) in 2024.

This report was compiled by the Centre for Environment, Fisheries and Aquaculture Science on behalf of the Environment Agency, Food Standards Agency, Food Standards Scotland, Natural Resources Wales, Northern Ireland Environment Agency and the Scottish Environment Protection Agency.

Requests for supporting documents and other information should be addressed to:

• in England and Wales, Radiological Monitoring and Assessment Team of the Environment Agency (enquiries@environment-agency.gov.uk), Food Policy Division of the Food Standards Agency (radiation@food.gov.uk) or Natural Resources Wales (enquiries@naturalresourceswales.gov.uk)
• in Scotland, the Radioactive Substances Unit of SEPA (radioactivesubstance@sepa.org.uk) or Food Standards Scotland (riskassessment@fss.scot)
• in Northern Ireland, the Industrial Pollution and Radiochemical Inspectorate of NIEA (IPRI@daera-ni-gov.uk)

Or alternatively,

Food Standards Agency

Food Policy Division
11^th Floor
64 Victoria Street
London
SW1E 6QP

Food Standards Scotland

4^th Floor
Pilgrim House
Old Ford Road
Aberdeen
AB11 5RL

Cyfoeth Naturiol Cymru / Natural Resources Wales

Welsh Government Offices
Cathays Park
King Edward VII Avenue
Cardiff
CE10 3NQ

Northern Ireland Environment Agency

Industrial Pollution and Radiochemical Inspectorate
Klondyke Building
Cromac Avenue
Lower Ormeau Road
Belfast
BT7 2JA

Navigating the report

The main report is split by nuclear sectors, each nuclear licensed site is allocated to a specific sector as given below.

• Nuclear fuel production and reprocessing (Section 3)
  • Capenhurst, Cheshire (Section 3.1)
  • Springfields, Lancashire (Section 3.2)
  • Cumbrian coastal area including Sellafield, Cumbria (Section 3.3)
• Nuclear power stations (Section 4)
  • Berkeley, Gloucestershire and Oldbury, South Gloucestershire (Section 4.1.1)
  • Bradwell, Essex (Section 4.1.2)
  • Dungeness, Kent (Section 4.1.3)
  • Hartlepool, County Durham (Section 4.1.4)
  • Heysham, Lancashire (Section 4.1.5)
  • Hinkley Point, Somerset (Section 4.1.6)
  • Sizewell, Suffolk (Section 4.1.7)
  • Chapelcross, Dumfries and Galloway (Section 4.2.1)
  • Hunterston, North Ayrshire (Section 4.2.2)
  • Torness, East Lothian (Section 4.2.3)
  • Trawsfynydd, Gwynedd (Section 4.3.1)
  • Wylfa, Isle of Anglesey (Section 4.3.2)
• Research and radiochemical production establishments (Section 5)
  • Dounreay, Highland (Section 5.1)
  • Grove Centre, Amersham, Buckinghamshire (Section 5.2)
  • Harwell, Oxfordshire (Section 5.3)
  • Winfrith, Dorset (Section 5.4)
  • Culham, Oxfordshire (Section 5.5)
• Defence establishments (Section 6)
  • Aldermaston and Burghfield (Section 6.1)
  • Barrow, Cumbria (Section 6.2)
  • Derby, Derbyshire (Section 6.3)
  • Devonport, Devon (Section 6.4)
  • Faslane and Coulport, Argyll and Bute (Section 6.5)
  • Rosyth, Fife (Section 6.6)
  • Vulcan NRTE, Highland (Section 6.7)
• Industrial, landfill, legacy and other non-nuclear sites (Section 7)

Data in figures and tables

The tables (in ODS format) and the underlying data for the figures contained in this report are available from the main RIFE page.

1. Introduction

Overview

• The Radioactivity in Food and the Environment (RIFE) report represents the collaboration between the UK’s environment and food standards agencies. The monitoring programme is independent of the nuclear industry’s own programmes.
• The RIFE report provides an independent and transparent check on food safety and the public’s exposure to radiation against relevant UK legislation
• The monitoring programme results help the UK meet its international treaty obligations.
• Annual radiation doses are summarised for nuclear and selected non-nuclear sites; all doses were below the annual legal limit of 1mSv in 2025.

This section:

• describes the scope and purpose of the UK monitoring programmes
• provides an overview of the main sources of radiation in a regulatory context
• outlines the management radioactive liabilities in the UK
• describes solid waste disposal at sea
• summarises other sources of radioactivity
• provides a summary of the key results in terms of radiation exposures at each nuclear and selected non-nuclear sites in 2025

1.1. Scope and purpose of the monitoring programmes

In England and Wales, the Food Standard Agency (FSA) and the Environment Agency^{[footnote 1]} carry out food and environmental (including seawater, sediments, dose rate) monitoring, respectively. The Scottish Environment Protection Agency (SEPA) (working closely with Food Standards Scotland (FSS) on its programme) and the Northern Ireland Environment Agency (NIEA) both undertake food and environmental monitoring in Scotland and Northern Ireland, respectively. Food monitoring includes the collection and analysis of cow’s milk (unless otherwise specified in this report). Surveillance of food imports through points of entry continued in 2025. The regular national programme of monitoring of sources of drinking water, air and rain continued on behalf of the Department for Energy Security & Net Zero (DESNZ), NIEA and the Scottish Government. The FSA and SEPA (as part of the joint SEPA and FSS monitoring programme) also carry out UK monitoring of milk and canteen meals that are collected remotely from nuclear sites. Annual surveys of seas around the UK (including locations away from nuclear sites) are monitored on behalf of DESNZ. The Environment Agency, NIEA, Natural Resources Wales (NRW) and SEPA are collectively referred to as the UK environment agencies. FSA and FSS are collectively referred to as the UK food standards agencies.

The RIFE report and the associated monitoring programmes were designed to conform to the requirements of Article 36 of the Euratom Treaty (see Section 8 and Appendix 1 in previous RIFE reports (for example, (Environment Agency and others, 2015) for more details).

The monitoring programmes have several purposes:

• environmental and food monitoring results are used to estimate and assess public radiation doses, confirm that permit and authorisation conditions provide adequate protection, and demonstrate compliance with legal dose limits; ongoing monitoring helps to establish the long-term trends in concentrations of radioactivity over time near, and at distance from, nuclear sites
• the results are also used to check for bioaccumulation of radioactivity in the food chain
• monitoring the environment provides indicators of radionuclide dispersion around each nuclear site

Most of the monitoring carried out and presented in this report concerns the local effects of current and historical discharges from nuclear sites in the UK. Monitoring of food and environmental media at locations remote from nuclear sites is also undertaken, providing information on background concentrations of radionuclides.

In previous years, the Environment Agency (with NRW providing advice on monitoring in Wales), the FSA, FSS and SEPA have all completed reviews of their environmental radioactivity monitoring programmes. Further information is available in earlier RIFE reports (for example, Environment Agency and others. 2020). Reviews are carried out to ensure the monitoring programmes are appropriate and are consistent with advice in the agency technical guidance (Environment Agency, Food Standards Agency, & Scottish Environment Protection Agency 2010; Scottish Environment Protection Agency 2019a), resulting in an adjustment and consolidation of the monitoring activities around some sites. The monitoring programmes may also vary from year to year due to sample and location availability.

The FSA has responsibility for food safety in England, Northern Ireland, and Wales, and FSS has this responsibility in Scotland. The environment agencies are responsible for regulating environmental protection in England, Northern Ireland, Wales, and Scotland. This includes the regulation of radioactive discharges and radioactive waste disposal from nuclear and non-nuclear sites.

1.2. Sources of radiation exposure

1.2.1. Radioactive waste disposal from nuclear sites

The permits (see Appendix 1) issued by the environment agencies to nuclear sites require operators to use best available techniques (England and Wales) or best practicable means (Scotland) and minimise the volume and activity of all forms of radioactive waste generated^{[footnote 2]}. The UK environment agencies consider that the terms best practicable means and best practicable environmental option (BEPO) as broadly equivalent to the application of Best Available Techniques (Scotland & Northern Ireland Forum for Environmental Research 2005; Scottish Environment Protection Agency 2019b). They also limit any liquid or gaseous discharges and specify appropriate arrangements for the disposal of solid low-level waste (LLW) to a suitable disposal site.

Solid LLW from nuclear sites may be sent for treatment or transferred to the low level waste repository (LLWR) for disposal. Solid wastes containing low quantities of radioactivity can also be disposed of at permitted solid waste disposal sites (see Section 7). Solid LLW from Dounreay, intended for disposal, can be transferred to the Dounreay LLW facility.

Figure 1.1 shows the nuclear sites, and their respective nuclear sectors, that produce waste containing artificial radionuclides, across the UK. Nuclear sites are permitted or authorised to dispose of radioactive waste and are also regulated by the Office of Nuclear Regulation under the Nuclear Installations Act 1965 (United Kingdom - Parliament 1965). The monitoring programmes reported here cover all these sites.

Permitted or authorised discharges, disposals of radioactive wastes and solid waste transfers (in Scotland) from nuclear establishments in 2025, are given in Appendix 1 (Table A1.1 to Table A1.4, inclusive). The tables also list the site discharge and disposal limits that are specified or, in the case of the Ministry of Defence (MOD), administratively agreed. In 2025, discharges and disposals were all below permitted/authorised limits.

These discharge limits are set through an assessment process, initiated either by the operator or the relevant environment agency. In support of the process, prospective assessments of doses to the public are made assuming discharges at the specified limits (Environment Agency, Scottish Environment Protection Agency, and others. 2012). Using this conservative assumption, discharge limits are set so that doses to the public will be below the source and site dose constraints of 0.3 and 0.5mSv per year, respectively (Environment Agency, Scottish Environment Protection Agency, and others, 2012). The determination of discharge limits considers a comprehensive range of pathways including the consumption of food. When determining the limits, the effect of the planned discharges on the environment and wildlife is taken into account.

The discharges and disposals made by sites do not normally fluctuate significantly. However, from time to time there may be unplanned events that cause unintended leakages, spillages or other emissions that are different to the normal or expected pattern of discharges. These events must be reported to the environment agencies and may lead to follow up action, including reactive monitoring by the site, the environment agencies, or the food standards agencies. Where monitoring took place because of these events, the results are presented and discussed in the relevant site text later in this report. Appendix 1 (Table A1.5) summarises the types of events that occurred in 2025.

Figure 1.1. Current nuclear sites in the UK, 2025. (Some operations are undergoing decommissioning).

1.2.2. Radioactive waste disposal from non-nuclear sites

Discharges of radioactive waste from non-nuclear sites such as hospitals, industrial sites and research establishments are also regulated under relevant environmental legislation, but not subject to the Nuclear Installations Act. Occasionally, radioactivity is detected in the environment during monitoring programmes because of discharges from these sites. For example, iodine-131 discharged from hospitals is occasionally detected in river and marine samples. Some very low level solid radioactive wastes are disposed of from non-nuclear sites to approved solid waste treatment or disposal sites (for controlled burial, incineration, or other treatment or disposal methods). There is also a radiological impact due to historical discharges of naturally occurring radionuclides, at enhanced concentrations, from non-nuclear industrial activity. This includes radionuclides discharged from the former phosphate processing plant near Whitehaven, and so monitoring is carried out near this site.

Routine monitoring is not usually undertaken around non-nuclear sites; however, some limited monitoring programmes are undertaken in Cumbria, Lancashire and Northamptonshire (Section 7). In Scotland, SEPA carries out routine sampling in the Firth of Clyde and at solid waste disposal sites to assess the impact of non-nuclear premises on the environment. Additionally, to ensure the doses from combined discharges to a sewer network are assessed properly, SEPA periodically undertakes intensive sampling at major sewage treatment plants to monitor the combined discharges from the non-nuclear industry.

Section 7 gives information on discharges from non-nuclear sites. The process for setting discharge limits is described in Section 1.2.1.

1.2.3. Radioactive waste disposal from future nuclear sites (Nuclear new build)

As regulators of nuclear new build in England and Wales, the Office of Nuclear Regulation (ONR), the Environment Agency and NRW, are working together to ensure that any new nuclear power stations built in the UK meet high standards of safety, security, environmental protection, and waste management through the generic design assessment process. The steps undertaken by the regulators are described in previous RIFE reports (Environment Agency, Food Standards Agency, and others 2021). More information on the generic design assessment process can be found here: https://www.gov.uk/guidance/new-nuclear-power-stations-assessing-reactor-designs and https://www.onr.org.uk/generic-design-assessment/assessment-of-reactors/. The process for setting discharge limits is described in Section 1.2.1.

Currently, only 2 sites, Hinkley Point C and Sizewell C have received approval for power generation.

NNB Generation Company (HPC) Limited is continuing the construction of a new twin UK European Pressurised Reactor™ (EPR™) nuclear power station at Hinkley Point C in Somerset. The ONR and Environment Agency continue to regulate both the construction and the development of the operating organisation. The Environment Agency regulates environmental matters at the site through permits covering both construction-related and operational activities. The development of NNB Generation Company (HPC) Limited is of interest to both regulators to ensure that the company has the competences and resources required to secure safety, security, and environment protection throughout construction and operation as it prepares itself to be an operator.

The ONR and the Environment Agency are continuing to work with Sizewell C Limited (previously NNB GenCo (SZC) Limited) that is constructing a new nuclear power station at Sizewell C, Suffolk. The radioactive substances permit and the nuclear site licence were issued by the Environment Agency and the ONR in 2023 and 2024, respectively. The project replicates the Hinkley Point C station.

In November 2025, Wylfa in North Wales was selected as the deployment site for the first fleet of Small Modular Reactors, with Rolls-Royce SMR Ltd being selected as the preferred technology partner.

Further plans to develop and build new nuclear power station in England and Wales have been outlined in the UK government’s ‘Civil Nuclear: Roadmap to 2050’, published in 2024 (Department for Energy Security and Net Zero 2024). The Scottish Government does not support the building of new nuclear power plants in Scotland, under current technologies (Scottish Government 2023).

1.3 Managing radioactive liabilities in the UK

The UK government has been managing radioactive waste for many decades in accordance with the Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management (International Atomic Energy Agency 1997). This convention aims to ensure that individuals, society, and the environment are protected from the harmful effects of ionising radiation, from the management of spent nuclear fuel and radioactive waste. Further information relevant to the UK demonstrating compliance under the Joint Convention is available in earlier RIFE reports (for example, (Environment Agency and others, 2019)). The most recent UK national report was presented at the 8^th Review Meeting in March 2025 (Department for Energy Security & Net Zero 2024).

The UK is a contracting party to the Convention for the Protection of the Marine Environment of the North-East Atlantic (the ‘OSPAR Convention’).

This provides a framework for preventing and eliminating pollution in the north-east Atlantic, including the seas around the UK (OSPAR 2021a; OSPAR 2021b). The North-East Atlantic Environment Strategy (NEAES) 2030 includes a new strategic objective:

“OSPAR will prevent pollution by radioactive substances in order to safeguard human health and to protect the marine environment, with the ultimate aim of achieving and maintaining concentrations in the marine environment at near background values for naturally occurring radioactive substances and close to zero for human made radioactive substances.”

This strategic objective will be delivered through 4 operational objectives as described in (OSPAR 2021b; Environment Agency and others, 2024). The outcomes of the 2020 Radioactive Substances Strategy (RSS) have been described in previous RIFE reports.

The importance of an integrated approach to stewardship of the marine environment has long been established in the UK. The reports ‘Safeguarding Our Seas’ (Department of Agriculture Environment and Rural Affairs, Scottish Executive, & Welsh Assembly Government 2002) and ‘Charting Progress 2’ (Department for Environment Food & Rural Affairs 2010), provided an initial strategy and assessment on the state of the UK seas. Further information concerning other individual and fully integrated assessments is available in earlier RIFE reports (for example, Environment Agency and others, 2018).

Following its withdrawal from the Euratom Treaty, the UK is no longer required to report these data to the European Commission and has agreed a Nuclear Cooperation Agreement (NCA) with the European Union (EU), ensuring both parties continue working together on civil nuclear matters including safeguards, safety, and security.

The Environment Agency, FSA, FSS, NRW, NIEA, SEPA and DESNZ have produced 3 RIFE summary reports, which support the UK’s OSPAR and Joint Convention obligations, and these are available via the main RIFE report page.

In 2010, the Marine Strategy Regulations 2010 (Statutory Instruments 2010a) came into force. These Regulations require the Secretary of State, Scottish Ministers, the Welsh Ministers and certain government departments in Northern Ireland to take action to achieve or maintain good environmental status (GES) in our seas (subject to certain exceptions) through the production of a “Marine Strategy” for all UK waters and that this is coordinated across the 4 UK Administrations. The UK Marine Strategy provides the framework for assessing and taking measures to achieve and maintain GES in our seas. It covers a wide range of biodiversity and marine environment descriptors including contaminants, and contaminants in seafood. Data in the RIFE report is used to support the UK Marine Strategy to demonstrate where GES has been achieved and maintained. More information on Descriptor 8 (contaminants) can be found at Marine Online Assessment Tool.

The UK Marine Strategy is split into 3 parts:

• part 1 - updated assessment Good Environmental Status (GES) of UK seas, published in 2026, to include an assessment towards achieving GES and revised targets or indicators.
• part 2 - setting out the UK marine monitoring programmes, published in 2014 and 2021 (to take account of the revised part 1)
• part 3 – programme of measures, published in 2015 and 2025

Further details on the UK Marine Strategy can be found on: Marine Online Assessment Tool.

The Nuclear Decommissioning Agency (NDA), a non-departmental public body, manages the decommissioning and clean-up of the civil public sector nuclear sites. The NDA reports to DESNZ and is responsible to Scottish ministers. The role of the NDA is strategic, developing and implementing an overall strategy for addressing the UK’s civil nuclear legacy. The NDA’s strategic objective is to manage radioactive waste and dispose of it where possible, or place it in safe, secure, and suitable storage, in line with the UK and devolved administrations’ policies. The Energy Act 2004 (United Kingdom - Parliament 2004) requires the NDA to review and publish its strategy every 5 years. Its most recent strategy was published in 2026 (Nuclear Decommissioning Authority 2026) and the business plan for 2026 to 2029 is available (Nuclear Decommissioning Authority 2026). In 2025 the NDA’s subsidiary body Nuclear Waste Services Ltd (NWS) published an inventory and forecast of radioactive wastes in the UK (Nuclear Waste Services 2026a; Nuclear Waste Services 2026b) and a Mission Progress Report in 2024 (Nuclear Decommissioning Authority no date).

Solid LLW requiring management continues to be produced by both nuclear and non-nuclear sites. The current UK Strategy for the management of solid LLW from the nuclear industry, published in 2016 (Department of Energy and Climate Change and others, 2016), promotes the application of the waste hierarchy and the use of risk-informed, fit-for-purpose waste management routes for LLW based on the characteristics of the waste. Whilst some LLW is disposed of at near-surface disposal facilities such as the LLWR and the Dounreay LLW Facility, operators are therefore encouraged to consider alternative management options, including reuse, recycling and treatment, where these represent an optimised solution.

In 2024, DESNZ, the Scottish Government, Department of Agriculture, Environment and Rural Affairs and the Welsh Government published the UK policy framework for the management of radioactive substances and nuclear decommissioning (Department for Energy Security & Net Zero and others, 2024).

The NDA is responsible for implementing UK and Welsh Government policies on the long-term management of higher activity radioactive waste (HAW) either through geological disposal or, in the case of less hazardous HAW, disposal at near-surface facilities. It is also responsible for implementing Scottish Government policy, which is that the long-term management of all HAW should be in near-surface facilities (Natural Scotland, Scottish Government 2011; Scottish Government 2016) . Facilities should be located as near to the site where the waste is produced as possible. Guidance to site operators and regulatory position statements on the management of HAW on licensed sites has been issued by the Environment Agency, NRW, SEPA and the ONR (Environment Agency, Office for Nuclear Regulation, and others, 2021; Office for Nuclear Regulation and others, 2021).

The UK government’s initial framework on geological disposal was set out in 2008 (Department for Environment Food & Rural Affairs and others, 2008), and last updated in 2024 (Department for Energy Security & Net Zero and others, 2024). The Scottish Government, Welsh Government and Northern Ireland Executive each have responsibility for determining disposal policy in their respective areas. Further information on the aspects of Geological Disposal Facility (GDF) is available on the GOV.UK website: geological disposal facility for high activity radioactive waste and GDF (Geological Disposal Facility) - GOV.UK

The Committee on Radioactive Waste Management (CoRWM) continues to provide independent scrutiny of the government’s long-term management, storage, and disposal of radioactive waste. This committee has published its annual report for 2025 (Committee on Radioactive Waste Management no date), proposed work programme for 2026 and a position paper on Radioactive Waste Burning by Nuclear transmutation (Committee on Radioactive Waste Management 2025).

The environment agencies published guidance on requirements for authorisation for geological and for near-surface disposal facilities in 2009 (Environment Agency, Northern Ireland Environment Agency, & Scottish Environment Protection Agency 2009; Environment Agency & Northern Ireland Environment Agency 2009; Environment Agency 2012). They launched consultations on updated guidance, in late 2024 for England, Wales and Northern Ireland, and in early 2025 for separate guidance in Scotland. They aim to publish their finalised guidance in late 2026. In May 2019, SEPA issued guidance on the decommissioning of non-nuclear facilities (for example, individual laboratories) from the use radioactive of radioactive substances (Scottish Environment Protection Agency 2020).

Decommissioning of many nuclear sites in Great Britain is currently underway. In 2018, the ‘Guidance on Requirements for Release of Nuclear Sites from Radioactive Substances Regulation’, referred to as ‘GRR’ was published (Scottish Environment Protection Agency, Environment Agency, & Natural Resources Wales 2018). This guidance describes what operators must do to release sites from radioactive substances regulation and is also available via: decommissioning of nuclear sites and release from regulation.

Some industrial activities give rise to wastes containing elevated concentrations of naturally occurring radionuclides, commonly referred to as Naturally Occurring Radioactive Material (NORM) Further information relevant to the UK NORM Waste Strategy, published in 2014, is available in earlier RIFE reports (for example, (Environment Agency and others, 2018)).

1.4 Solid radioactive waste disposal at sea

In the past, packaged solid waste of low radioactivity concentrations was disposed of deep in the North Atlantic Ocean, the last disposal of this type was in 1982. The UK government announced at the OSPAR Ministerial meeting in 1998 that it was stopping disposal of this material at sea. At that meeting, Contracting Parties agreed that there would no longer be any exception to prohibiting the dumping of radioactive substances, including radioactive waste (OSPAR 1998). The environmental impact of the deep ocean disposals was assessed by detailed mathematical modelling and has been shown to be negligible (Organisation for Economic Co-operation and Development Nuclear Energy Agency 1985). Disposals of small amounts of waste also took place from 1950 to 1963 in a part of the English Channel known as the Hurd Deep. The results of environmental monitoring of this area are presented in Section 8 and confirms that the radiological impact of these disposals was insignificant.

In England, the Marine Management Organisation administers a range of statutory controls that apply to marine works on behalf of the Secretary of State for Environment, Food and Rural Affairs. This includes issuing licences under the Marine and Coastal Access Act 2009 (United Kingdom - Parliament 2009) for the disposal of dredged material at sea. In Northern Ireland, Scotland and Wales, licences for disposal of dredged material at sea are the responsibility of Department of Agriculture Environment and Rural Affairs (DAERA), the Scottish Government (Marine Scotland) and NRW, respectively.

The protection of the marine environment is considered before a licence is issued. Since dredged materials will contain varying concentrations of radioactivity from natural and artificial sources, assessments are carried out, when appropriate, to provide reassurance that there is no significant risk to the food chain, human health or the marine environment from the disposal. Guidance on exemption criteria for radioactivity in relation to sea disposal is available (International Atomic Energy Agency 1999). The International Atomic Energy Agency (IAEA) has published a system of assessment that can be applied to dredged spoil disposal (International Atomic Energy Agency 2003; International Atomic Energy Agency 2015) and which has been adapted to reflect operational practices in England and Wales (McCubbin & Vivian 2006).

1.5 Other sources of radioactivity

There are several other anthropogenic sources of radioactivity that may affect the food chain and the environment. These could include disposals of material from offshore installations, transport incidents, satellite re-entry, releases from overseas nuclear installations and the operation of nuclear-powered submarines. UK Health Security Agency (UKHSA) has assessed incidents involving the transport of radioactive materials in the UK (Jones & Harvey 2014). UKHSA have also considered the effects of discharges into the marine environment from the oil and gas industry, with the estimated highest individual dose (per head of population) being less than 0.001mSv per year (Harvey, Smith & Cabianca 2010). Submarine berths in the UK are monitored by the MOD (for example, Defence Science and technology Laboratory 2026). General monitoring of the British Isles is carried out as part of the programmes described in this report, to detect any significant effects from the sources above. No such effects were found in 2025. Low concentrations of radionuclides were detected in the marine environment around the Channel Islands (Section 8), and these may be partly due to discharges from the nuclear fuel reprocessing plant at La Hague in France.

The effects of exploration for, and extraction of, gas from shale rock have been investigated in the UK with support from DESNZ. Further details on shale gas development and hydraulic fracturing (“fracking”) in the UK is available on the GOV.UK website: about shale gas and hydraulic fracturing (fracking).

Further information on the previous involvement by each of the environment agencies to support engagement with industry, and other related issues to shale gas extraction, is available in earlier RIFE reports (for example, RIFE 29 (Environment Agency and others, 2024)).

Another potential source of radioactivity in the UK is land which has been contaminated by radioactivity from historical activities. The Environmental Protection Act 1990 provides the basis for a regulatory regime for identifying and remediating contaminated land. In the UK, there is a duty to inspect land under Part ll A of the Environmental Protection Act 1990, but there must be reasonable grounds for inspecting land for radioactivity. Reasonable grounds are defined in the statutory guidance.

DESNZ issued guidance for radioactive contaminated land to local authorities and the Environment Agency, which was last updated in 2018 (Department of Business Energy and Industrial Strategy (BEIS) 2018). Clear dose criteria are set for homogeneous and heterogeneous contamination. Also, the risk (probability or frequency of occurrence) of receiving the dose should be considered for the designation of radioactive contaminated land. To date, no site has been legally designated as ‘radioactive contaminated land’ due to radioactivity in England and Wales.

Equivalent legislation exists as Statutory Instruments in Northern Ireland through the Radioactive Contaminated Land Regulations (Northern Ireland) 2006 and subsequent amending legislation introduced in 2007 and 2010 (Statutory Instruments 2007; Statutory Instruments 2010b).

In 2007, the Radioactive Contaminated Land (Scotland) Regulations came into force by amending Part ll A of the Environmental Protection Act 1990. SEPA has powers to inspect land that may be contaminated with radioactivity, to decide if land should be identified as radioactive contaminated land and require remediation if considered necessary. Revised Statutory Guidance was issued to SEPA in 2009. This guidance is broadly similar to that issued to the Environment Agency. In Scotland, clear dose criteria are set for homogeneous and heterogeneous contamination. Also, the risk (probability or frequency of occurrence) of receiving the dose should be considered for the designation of radioactive contaminated land. To date, no site has been designated as ‘contaminated land’ due to radioactivity in Scotland.

The contribution of aerial radioactive discharges from UK installations to concentrations of radionuclides in the marine environment has been studied (Department for Environment Food & Rural Affairs 2004). The main conclusion was that aerial discharges do not make a significant contribution to activity concentrations in the marine environment. On occasion, the effects of aerial discharges may be detected in the aquatic environment, and conversely the effects of aquatic discharges may be detected on land. Where this is found, appropriate comments are made in this report.

Only a small proportion of the public’s exposure to ionising radiation originates from anthropogenic sources of radioactivity. All sources of ionising radiation exposure to the UK population are reviewed by UKHSA, the most recent report was published in June 2025: UK Ionising Radiation - UKHSA (UK Health Security Agency). The most significant source of exposure was from natural radiation (radon and thoron gases). Figure 1.2 provides a breakdown of the exposure to the UK population by source;

Figure 1.2. Average UK population exposure from natural and artificial sources of radioactivity (UKHSA radiation and you)

Category	Percentage of total exposure from natural and artificial sources of radioactivity
radon and thoron in the home (from naturally occurring sources)	44
diagnostic medical procedures	16
terrestrial gamma radiation	14
cosmic radiation (non-occupational)	13
intake of naturally occurring radionuclides, excluding radon	10
occupational exposure to natural sources	4.0
other sources	0.3

The average individual dose from exposure to all significant sources of ionising radiation was estimated to be about 2.6mSv per year, the same as that reported in the previous reviews (Watson and others, 2005; Oatway and others, 2016). Environmental sources of radiation contributed approximately 84% (2.2 mSv per year) of the average individual dose received from all sources. This was dominated by exposure to naturally occurring sources of radiation although there is significant variation across the UK due to local geology and other factors. Only about 0.3% of the annual dose was from artificial sources; and of this, the majority was from radionuclides released during historical testing of nuclear weapons in the atmosphere (global fallout) from the 1950s and 1960s (hereafter referred to as ‘nuclear weapons testing’), with exposure to radionuclides routinely discharged by industry contributing less than 0.01% to the total dose. As the average member of the UK population does not live near a nuclear discharge point, the doses from nuclear discharges will be underestimated.

1.6. Summary of radiation doses

1.6.1. The assessment process

Most of the monitoring was carried out to determine the effects of discharges from nuclear and non-nuclear sites on the food people consume and their environment. The results are used to estimate and assess annual radiation doses to the public that can then be compared with the relevant dose limits. Dose assessments are retrospective in that they apply to 2025 using monitoring results for that year. The radioactivity concentrations and dose rates reported are spot measurements that reflect the combined radiological impact of all discharges

In this report, 2 main types of retrospective doses are assessed, ‘total dose’ and ‘source-specific’ doses.

‘Total dose’ assessments consider the doses from radioactive discharges (gaseous and liquid) to the environment from nuclear sites combined with the dose from radiation sources on site (direct radiation). This assessment gives an estimate of the annual ‘total dose’ to people living near the nuclear sites. The ‘total dose’ assessment is the main method for estimating radiation exposure to the public.

Source-specific assessments estimate the annual dose from individual sources of radioactivity and associated exposure pathways (see Appendix 2, and Appendix 5 for more information). These dose assessments provide reassurance on the robustness and reasonableness of the annual ‘total dose’ method (which is the preferred assessment type (Environment Agency, Scottish Environment Protection Agency, and others 2012)) and provide information for a range of additional exposure pathways. The sum of the doses from specific sources (terrestrial and aquatic) cannot be directly compared to the assessment of ‘total dose’ from all sources. This is because the assessment methods use different ways of defining the most exposed people.

The sources considered, habits and monitoring data used, and the dose calculations are described in this report. The primary purpose of each assessment approaches is to identify and assess the main exposure pathways at each site and to demonstrate compliance with the dose limit of 1mSv y^-1.

Exposure from direct radiation may be a significant contributor to dose, close to a nuclear site, due to radiation emitting from sources on the site^{[footnote 3]}. The ONR is responsible for regulating direct radiation. In 2018, EDF revised its method of direct radiation dose (EDF Energy 2018). Therefore, values since 2018 will differ from the generic values given previously. The operators of nuclear sites provide estimates of direct radiation doses to the ONR (Table 1.1); annual exposure data are then made available for use in ‘total dose’ assessments. These dose assessments use recent habits survey data from which different habits profiles have been created using an agreed method (Camplin, Grzechnik & Smedley 2005). Data tables and the detailed results of the dose assessments, in Open Document Spreadsheet (ODS) format, are downloadable from the main RIFE page.

Both types of assessment consider those people in the population most exposed to radiation (the ‘representative person’). The results from both types of assessments are compared with legal limits (1mSv y^-1 for members of the public and 50mSv y^-1 specifically for skin exposure). The effective doses (defined in Appendix 2) are calculated and compared with the legal dose limit of 1mSv per year for members of the public. All legal radiation dose limits in the UK are based on recommendations made by the International Commission on Radiological Protection (ICRP) (International Commission on Radiological Protection 2007), which are consistent with Basic Safety Standards Directive 13 (European Commission 2014). The radiation dose specifically to skin is also assessed in some cases and compared with the legal limit for skin exposure.

The radiation doses resulting from human activities may be compared with doses received from naturally occurring sources of radioactivity. The average individual radiation dose in the UK population (in 2025) from natural radiation was estimated by UKHSA to be approximately 2.2mSv per year (UKHSA - ionising radiation) (UK Health Security Agency)

Radiation exposures to some specific groups of workers are included in the assessment of doses from nuclear sites. These are people who may receive exposure as a consequence of their work activities, such as fishers, farmers, and sewage workers. It is appropriate to compare their doses to the dose limit for members of the public (Allott 2005). Those people who specifically work with ionising radiation have their radiation doses assessed and recorded as part of their employer’s programme to assess occupational exposure (United Kingdom - Parliament 1999).

1.6.2. ‘Total dose’ results for 2025

The results of the assessment for each site are summarised in Table 1.2 (see also Figure TS and Table S in the Technical Summary). These data are presented in 3 parts. Part A shows the representative person receiving the highest annual doses from gaseous discharges and direct radiation pathways. Part B shows the representative person receiving the highest annual doses from liquid discharges. Part C shows the representative person receiving the highest annual dose from all pathways and sources; occasionally, the people receiving the highest doses from all pathways and sources are different from those in parts A and B. In some cases, the selection of profiles may be driven by the inclusion of pathways that have higher consumption/occupancy rates than in the respective profiles, for example, for Capenhurst, part A, the profile selected (infant poultry meat consumers) is due to the additional contribution from consumption of root vegetables. The major contributions to the total dose are provided. The use of radionuclide concentrations reported at the limits of detection provide an upper estimate of doses calculated for pathways based on these measurements. The full output from the assessment for each site can be provided by contacting one of the agencies listed on the inside front or back covers of this report or downloaded from the main RIFE page,

In all cases, doses estimated for 2025 were less than the annual limit of 1mSv for members of the public. The people most affected from gaseous discharges and direct radiation varied from site to site but the dominant pathway was often direct radiation (from the relevant site), where it was applicable. The people most affected from liquid discharges were generally adults eating seafood or people who spend long periods of time over contaminated sediments, which are coastal or other areas that are impacted by liquid discharges.

The representative person who received the highest annual ‘total dose’ (0.51mSv), is from the Cumbrian Coastal Community (near Sellafield) who consumed crustaceans at high rates, together with other seafood. The ‘total dose’ (from all sources) at this site is combined with the effects of all local sources, including specifically the effects of historical discharges of natural radionuclides from the former phosphate processing plant. The next highest annual ‘total doses’ were received by people living near the Capenhurst (0.18mSv) and Aldermaston and Burghfield (0.10mSv) sites these doses were almost entirely due to direct radiation from the site.

1.6.3. ‘Total dose’ trends

Data for the time-series of annual ‘total dose’ from 2008 to 2025 is given in Table 1.3. In all cases, the assessed ‘total doses’ were less that the 1mSv dose limit to members of the public. Detailed plots and discussion on the trends are given in the relevant site sections and supporting texts.

1.6.4 Source-specific dose results for 2025

The results of the source-specific assessments for the sites assessed in the UK are summarised in Figure 1.3 and Table 1.4, which contains numerical data and the major contributors to dose. Figure 1.3 shows the assessed source-specific doses for 2025, both from gaseous and liquid sources, compared to the 1mSv dose limit to members of the public. Doses ranged from less than 0.005mSv (at many sites) to 0.44mSv from all liquid sources along the Cumbrian Coast, including a significant contribution to the dose from historical discharges of naturally occurring radionuclides from the former phosphate processing plant at Whitehaven. Doses from gaseous discharges, ranged from less than 0.005mSv to 0.64mSv, the latter from consumption of terrestrial foods around Sellafield (primarily caesium-137 in wild wood pigeon, discussed in Section 3.3.3.12). These assessments focus on the effect of gaseous or liquid waste discharges, unlike the assessment of ‘total dose’ which includes all sources including the effect of direct radiation.

At some sites, source-specific doses were higher than the corresponding total dose assessments. This difference comes from the use of different assessment assumptions. Source-specific assessments use conservative assumptions when combining the exposure effects from different food consumption pathways, whereas total dose assessments use more realistic assumptions about patterns of exposure. The estimates from the source-specific assessments provide reassurance that the ‘total dose’ approach is reasonable. Radiation doses to all age groups (see Section 2.6 for the age groups used), calculated using the source-specific method, were all found to be below the legal limit of 1mSv per year.

Figure 1.3(a). Source-specific doses, in mSv y^-1, from liquid discharges in the UK, 2025. (Exposures to the Cumbrian Coastal Community receive a significant contribution to the dose from historical discharges of naturally occurring radionuclides from the former phosphate processing plant at Whitehaven). Small doses less than or equal to 0.005mSv are recorded as being 0.005mSv.

Site name	Dose from liquid discharges, mSv y-1
Cumbrian Coastal Community	0.44
Barrow	0.065
Berkeley/Oldbury	0.028
Heysham	0.023
Hinkley	0.013
Trawsfynydd	0.012
Dungeness	0.010
Capenhurst	0.009
Dounreay	0.008
Faslane	0.008
Hunterston	0.008
Springfields	0.008
Hartlepool	0.007
Harwell	0.007
Chapelcross	0.006
Aldermaston	0.005
Amersham	0.005
Bradwell	0.005
Derby	0.005
Devonport	0.005
Rosyth	0.005
Sizewell	0.005
Torness	0.005
Winfrith	0.005
Wylfa	0.005
limit	1.0

Figure 1.3(b). Source-specific doses, in mSv y^-1, from gaseous discharges in the UK, 2025. Small doses less than or equal to 0.005mSv are recorded as being 0.005mSv.

Site name	Dose from gaseous discharges, mSv y-1
Sellafield	0.64
Hunterston	0.025
Trawsfynydd	0.021
Dounreay	0.013
Chapelcross	0.006
Torness	0.006
Aldermaston	0.005
Amersham	0.005
Barrow	0.005
Berkeley and Oldbury	0.005
Bradwell	0.005
Capenhurst	0.005
Derby	0.005
Devonport	0.005
Dungeness	0.005
Faslane	0.005
Hartlepool	0.005
Harwell	0.005
Heysham	0.005
Hinkley	0.005
Low level waste repository	0.005
Sizewell	0.005
Springfields	0.005
Winfrith	0.005
Wylfa	0.005
limit	1.0

The most significant exposures from seafood (fish and crustacean shellfish) consumption were to the Cumbrian coastal community. The majority of the dose was from historical discharges of naturally occurring radionuclides from the former phosphate processing plant. The most important pathways and radionuclides at each site were similar to those found for ‘total dose’.

The most significant exposures from consumption of terrestrial foods were to people close to the Sellafield site. The majority of the dose was from enhanced levels of caesium-137 found in wild wood pigeon.

1.6.5. Protecting the environment

This report focuses primarily on risks to members of the public and on demonstrating that radiation doses remain below regulatory limits. However, the environment agencies also consider the protection of wildlife and the environment from radiation exposure caused by human activity. The 2007 recommendations of the International Commission on Radiological Protection (ICRP) concluded that a systematic approach to the radiological assessment of non-human species was required to support the management of radiation effects in the environment (International Commission on Radiological Protection 2007). The ICRP, introduced the concept of Reference Animals and Plants (RAPs) for a system of radiological environmental protection (International Commission on Radiological Protection 2008). The ICRP has published its aims covering:

1. prevention or reduction of the frequency of deleterious (harmful) radiation effects on biota (animals and plants) to a level where they would have a negligible impact on the maintenance of biological diversity
2. the conservation of species and the health and status of natural habitats, communities, and ecosystems (International Commission on Radiological Protection 2014). No dose limits are proposed to apply, but a set of derived consideration reference levels for representative species are recommended for use in assessing the impact of different sources of exposure

In the UK, the current legislative measures for protection of wildlife from radiation are implemented through The Conservation of Habitats and Species (Amendment) (EU Exit) Regulations 2019, known as the ‘Habitats Regulations’ (UK Statutory Instruments 2019).

Under the ‘Habitats Regulations’, the Environment Agency, NRW and SEPA are required to review existing authorisations or permits to ensure that no authorised activity or permission has an adverse effect, either directly or indirectly, on the integrity of Natura 2000^{[footnote 4]} habitat sites. Similarly, for any new or varied authorisation or permit, applicants must assess the potential effects of proposed discharges on reference organisms representing species that may be adversely affected.

The assessment of impacts on wildlife and plants (non-human) species is also considered during the determination of applications for new and varied environment permits. Further information concerning assessment of dose rates to reference organisms is available in earlier RIFE reports (for example, Environment Agency and others, 2017 ) and Environment Agency reports (Environment Agency 2009a; Environment Agency 2009b).

SEPA has carried out a pressures and impacts assessment from radioactive substances on Scotland’s water environment. The study concluded that there was no adverse impact on the aquatic environment as a result of authorised discharges of radioactive substances, although it recognised that there may be a need for further data to support this conclusion. SEPA has included a specific habitats assessment in any new authorisation granted by the agency.

2. Methods of sampling, measurement and presentation used in this report

This section explains the scope of the monitoring programmes presented in this report (hereafter referred to as ‘programmes’) and summarises the methods and data used to measure and assess radioactivity in food and the environment. The bulk of the programmes, assessment methods and supporting datasets used in 2025 were broadly unchanged from previous years, with no special sampling was required for unusual short-term increases in discharges or inadvertent releases. However, the main changes are summarised below:

Assessment and presentation

• new habits data - consumption and occupancy rates have been updated with the benefit of recent habits survey results at Barrow, Sellafield and Sizewell in England, and Dounreay in Scotland

Accompanying this report is a further set of files giving full details of each assessment of ‘total dose’ summed over all sources at each site. These are available on the main RIFE page.

The appendices of this report contain further details on:

• modelling to support or supplement the results of monitoring (Appendix 3)
• consumption, occupancy and other habits data (Appendix 4)
• dosimetric data (Appendix 5)
• estimates of concentrations of natural radionuclides (Appendix 6)

Guidance on planning and implementing routine environmental radiological monitoring programmes has been published Environment Agency radiological monitoring guidance and by SEPA (Scottish Environment Protection Agency 2019a). In recent years, the Environment Agency (with NRW providing advice on monitoring in Wales), FSA, FSS and SEPA have all completed reviews of their environmental radioactivity monitoring programmes. Further information is available in earlier RIFE reports (Environment Agency and others, 2017; Environment Agency and others, 2019) and in Section 1.1.

2.1. Sampling programmes

The primary purpose of the programmes is to measure the quantities of radioactivity in food and the environment. Results are used to demonstrate that the safety of the public is not compromised and that doses, resulting from discharges of radioactivity, are below the statutory dose limits (see Section 1 for more details). The scope in 2025 extends throughout the UK (and the Channel Islands) and is undertaken independently of the industries which discharge wastes to the environment. Samples of food, water and other materials are collected and analysed in specialist laboratories. In situ measurements of radiation dose rates and contamination are also made and the results of the programmes are assessed in terms of limits and trends in this report. Subsidiary objectives for the programmes are:

• to provide information for assessing the impact of radioactivity in the environment on non-human species
• to enable indirect confirmation of compliance with authorised or permitted waste disposals
• to determine whether undisclosed releases of radioactivity have occurred from sites
• to establish a baseline to judge the importance of accidental releases of radioactivity should they occur
• to demonstrate compliance with international obligations, such as The Oslo and Paris Convention for the Protection of the marine environment of the North-East Atlantic (OSPAR)

Routine sampling is focused on nuclear sites licensed under the Nuclear Installations Act, 1965 (United Kingdom - Parliament 1965). The programmes also serve to provide information to assist the environment agencies to fulfil statutory duties, which are further described in Section 1.1. Additional sampling is conducted in areas remote from nuclear sites to establish the general safety of the food chain, sources of drinking water and the environment. These data provide background activity concentrations against which results from areas near nuclear sites can be compared to show the variation in the quantities of radioactivity across the UK. Quantities of radioactivity in the environment can also be affected by disposals of radioactive waste from nuclear sites abroad and show the legacy of atmospheric fallout from both past nuclear weapons testing and the nuclear reactor accidents (such as at Chernobyl in Ukraine in 1986).

Various methods for undertaking sampling and analysis are available. The programmes are primarily directed towards widespread contamination where exposure through contact or consumption can reasonably be expected. Where a source of potential exposure to particles of radioactivity is concerned, the likelihood of encounter is an important factor. This is considered separately in this report in site-specific programmes targeted at contamination from radioactive particles on beaches near Sellafield (Section 3.3.3.6) and Dounreay (Section 5.2.3).

The programmes can be divided into 3 main sectors, generally based on the source of radioactivity in the environment:

• nuclear sites discharging gaseous and liquid radioactive wastes
• selected non-nuclear sites and solid waste disposal sites
• UK regional monitoring and overseas accidents

2.1.1. Nuclear sites

Nuclear sites are the primary focus of the monitoring programmes because they represent the most significant permitted/authorised sources of radioactive waste discharges. Sampling and direct monitoring is conducted close to most of the sites shown in Figure 1.1. Radionuclides from historical liquid discharges at Sellafield can be detected in the marine environment in many parts of north European waters. Therefore, programmes for this site extend beyond national boundaries.

The frequency and type of measurement and the materials sampled vary from site to site and are chosen to be representative of existing exposure pathways. Information on local peoples’ diets and way of life, from habits surveys, are used to inform the exposure pathways. Detailed information on the scope of the programme at individual sites is given in the tables of results. The routine programme is supplemented by additional monitoring if applicable, for example, in response to incidents or reports of unusual or high discharges of radioactivity with the potential to enter the food chain or the environment. Results of both routine and additional monitoring are included in this report.

The main aim of the programme is to monitor the environment and food consumed by people who live or work near nuclear sites, to estimate doses for those small groups of people who are more at risk of exposure to radioactivity from these sources. It is assumed that if the most exposed people have a dose below the national and international legal limit then doses to the wider population will also be below those limits. For liquid wastes, the pathways that are the most relevant to discharges are the ingestion of seafood and freshwater fish, drinking water and external exposure from contaminated materials. For gaseous wastes, the effects are due to the ingestion of terrestrial foods, inhalation of airborne activity and external exposure from material in the air and deposited on the ground. Inhalation of airborne activity and external exposure from airborne material and surface deposition are difficult to assess by direct measurement but can be assessed using environmental models. The main part of the monitoring is therefore directed at a variety of foodstuffs and measurements of external dose rates on the shores of seas, rivers and lakes. The programme also includes some environmental indicators that provide historical and contextual information on trends in environmental radioactivity.

2.1.2. Selected non-nuclear site and solid waste disposal sites

Although the emphasis of the monitoring programme is the nuclear sector, a small proportion of the monitoring programmes are focussed on other activities that may have a radiological impact on people and the food chain. This part of the programme considers the effect of disposals of naturally occurring and artificial radionuclides from non-nuclear industries and of disposal into solid waste disposal sites, other than at Dounreay (considered separately in Section 5).

The impact of the non-nuclear industry was studied at several locations in 2025 including East Northants Resource Management Facility (near Kings Cliffe), Clifton Marsh (Lancashire), Lillyhall (Cumbria), the River Clyde (Glasgow) and Whitehaven (see Section 7). As in recent years, a small-scale programme was undertaken near Hartlepool (see Section 4.1.4), in addition to that directed at the effects of the power station itself. Sampling and analysis reflected the nature of the sources (of radioactivity) under study and, where appropriate, included consideration of the enhanced concentrations of naturally occurring radionuclides from non-nuclear industrial activity. There are also occasional specific programmes that consider, for example, the effects of land contaminated with historical sources of radioactivity and discharges from non-nuclear sites such as hospitals.

The distribution of solid waste disposal sites considered in 2025 is shown in Figure 7.1. Sites were studied to assess the extent of radiological contamination, resulting from leachates from the site, re-entering the terrestrial environment (leachates accumulating in surface waters close to the sites).

2.1.3. UK regional monitoring and fallout in the UK from overseas accidents

The programme of regional monitoring considers the quantities of radioactivity in the environment in areas away from specific sources as an indication of general radiological contamination of the food supply and the environment. The component parts of this programme are:

• monitoring of the Channel Islands and Northern Ireland
• dietary surveys
• sampling of milk
• drinking water sources, groundwater, rain and airborne particulates
• seawater surveys
• fallout in the UK from overseas accidents

Channel Islands and Northern Ireland

The programmes for the Channel Islands and Northern Ireland are designed to complement that for the rest of the UK and to take into account the possibility of long-range transport of radionuclides.

Channel Islands monitoring is conducted on behalf of the Channel Island States. It consists of sampling and analysis of seafood and indicator materials as a measure of the potential effects of UK and French disposals into the English Channel and historical disposal of solid waste in the Hurd Deep.

Monitoring on the Isle of Man for foodstuffs and indicator materials ceased in 2013 and 2016 (Environment Agency and others, 2015; Environment Agency and others, 2016), respectively. Monitoring of the marine environment was primarily directed at the effects of disposals from Sellafield.

The Northern Ireland programme is directed at the far-field effects of disposals of liquid radioactive wastes into the Irish Sea. Seafood and indicator materials are collected from a range of coastal locations including marine loughs, and dose rates are monitored on beaches.

General diet

The purpose of the general diet survey programme is to provide information on radionuclides in the food supply to the wider population, rather than to those living near particular sources of radiological contamination such as the nuclear industry. This programme is based on sampling and analysis of canteen meals throughout the UK. It provides background information that is useful in interpreting site-related measurements and helps ensure that significant sources of radiological contamination are identified and appropriately reflected in site-specific monitoring programmes.

Specific foods, freshwater, rain and airborne particulates

Further background information on the relative concentrations of radionuclides is gained from the sampling and analysis of milk. Freshwater, rain and airborne particulates are also analysed to add to the understanding of radionuclide intakes by the population via ingestion and inhalation and as general indicators of the state of the environment.

Milk sampling took place at dairies throughout the UK in 2025.

Meat and crop monitoring of naturally occurring and artificial radionuclides, as a check on general food contamination, remote from nuclear sites, ceased in 2014. However, in 2025, surveillance of imported food at ports of entry using radiation screening equipment continued as a means of detecting the effects of overseas incidents. If screening and subsequent sample analysis shows quantities of radioactivity that fail to comply with UK food standards, which are retained from EU directives or regulations, then the consignments are removed from the UK market.

Freshwater used for the supply of drinking water was sampled throughout England, Northern Ireland, Scotland and Wales. Regular measurements of radioactivity in air and rainwater were also made.

Seawater surveys

Seawater surveys are conducted in the seas around the UK on behalf of the DESNZ to provide information on radionuclide concentrations and information on water transport mechanisms in the coastal seas of northern Europe. Such information is used to support international studies of the health of the seas under the auspices of the OSPAR Conventions (OSPAR 2000) (to which the UK is a signatory) and in support of research on the fate of radionuclides discharged to sea. These surveys are conducted using government research vessels and are supplemented by a programme of spot sampling of seawater at coastal locations.

Fallout in the UK from overseas accidents

Monitoring of the long-range effects of the Fukushima Dai-Ichi accident started across the UK in March 2011. Samples from all sectors of the environment were taken and analysed by gamma spectrometry. The most significant radionuclides to monitor were iodine-131 and caesium-137, which were prevalent in the release from the accident. Very low activity concentrations were detected, and the extended programme ceased later in 2011. Further details of the programme and the results are given in the RIFE report for 2011 (Environment Agency, Food Standards Agency, and others, 2012).

Monitoring of the effects of the 1986 Chernobyl accident was undertaken in relation to the upland contamination of lakes. Earlier RIFE reports have provided detailed results of monitoring by the environment agencies and FSA (Environment Agency and others, 2013). Sheep monitoring ceased in 2012 due to the removal of restrictions on the movement, sale and slaughter of sheep in parts of Cumbria and North Wales. Sampling for freshwater fish in locations affected by Chernobyl ceased in 2014.

2.2. Methods of measurement

There are 2 basic types of measurement made:

• dose rates are measured directly in the environment
• samples collected from the environment are analysed for their radionuclide content in a laboratory

2.2.1. Sample analysis

Analysis of samples varies depending on the nature of the radionuclide under investigation. The types of analysis can be broadly categorised into 2 groups:

• gamma-ray spectrometry
• radiochemical methods

The former is a cost-effective method of detecting a wide range of (gamma-emitting) radionuclides, commonly found in radioactive wastes, and is used for most samples. Radiochemical methods consist of a range of analyses involving the application of chemical separation and purification techniques to quantify the concentrations of alpha- and beta-emitting radionuclides. These are sensitive determinations, but generally more labour intensive. These methods are only used if alpha and beta concentration data are required for specific radionuclides and are not detectable using gamma-ray spectrometry (see Section 2.4 for discussion on limits of detection).

Several laboratories analysed samples in the monitoring programmes described in this report. Their main responsibilities were as follows:

Cefas

Centre for Environment, Fisheries and Aquaculture Science, gamma-ray spectrometry and radiochemical analysis of food samples in England, Wales, Northern Ireland and the Channel Islands

SOCOTEC

SOCOTEC UK Limited, gamma-ray spectrometry and radiochemical analysis of environmental samples (including analysis of sources of drinking water) in England and Wales

UKHSA

UK Health Security Agency, gamma-ray spectrometry and radiochemical analysis of food and environmental samples from Scotland, air and rain samples in England, Wales and Northern Ireland, and freshwater for Northern Ireland

Each laboratory operates quality control procedures to the standards required by the UK environment and food standards agencies and have their analytical procedures independently assessed by the UK Accreditation Service. This ensures the requirements from the international standard ISO 17025 (International Organisation for Standardisation 2017) are maintained. Regular calibration of detectors is undertaken, and intercomparison exercises are held with participating laboratories. The quality assurance procedures and data are made available to the UK environment agencies, FSA and FSS for auditing. The methods of measurement include alpha and gamma-ray spectrometry; beta and Cerenkov scintillation counting; and alpha and beta counting using proportional detectors.

Corrections are made for the radioactive decay of short-lived radionuclides between the time of sample collection and measurement in the laboratory. This is particularly important for sulphur-35 and iodine-131. If a sample is bulked from a sequence of samples over time, the date of collection of the bulked sample is assumed to be in the middle of the bulking period. Otherwise, the actual collection date for the sample is used. In a few cases where short-lived radionuclides are part of a radioactive decay chain, the additional activity (‘in-growth’ and equilibrium status) produced from radioactive decay of parent and daughter radionuclides after sample collection is also considered. Where necessary, corrections to the activity present at the time of measurement are made to take account for this.

The analysis of foodstuffs is conducted on the part of the sampled material that is normally eaten, for example, shells of shellfish and the pods of some legumes are discharged before analysis. Most other foodstuffs are analysed raw, as it is conceivable that all the activity could be consumed in the raw foodstuff. Some shellfish samples are cooked (boiled) to represent processing by members of the public and therefore, some activity will be lost as a consequence. Several studies have investigated the loss of activity of caesium-137, strontium-90 and polonium-210, which are dependent upon cooking method (Masson and others, 1989; Rantavaara 1989; International Atomic Energy Agency 1992; Saiki 1994; International Atomic Energy Agency 2009; NABESHI and others, 2013; Uddin and others, 2019; Abd-Elghany and others, 2020; Johansen and others, 2023). The retention factors for caesium-137 in bivalve molluscs varied from 0.49 to 1.30 (Masson and others, 1989; International Atomic Energy Agency 1992). The Uddin (Uddin and others, 2019) and Johansen (Johansen and others, 2023) studies suggest lower retention factors when samples are boiled or steamed, rather than grilled or fried, with polonium-210 retention factors of 0.58 and 0.56 for crustacean and bivalve molluscs, respectively (Johansen and others, 2023). The depuration of transuranic radionuclides from edible winkles has been studied by Swift (Swift 1995).

2.2.2. Measurement of dose rates and contamination

Measurements of gamma dose in air over intertidal and other areas are normally made at 1 metre above the ground using RadEye SX Survey Meters or Mini Instruments^{[footnote 5]} environmental radiation meters type 6-80, with both types of meters connected to compensated Geiger-Muller tubes, type MC-71. In some scenarios, for example, for people living on houseboats or for wildfowlers lying on the ground, measurements at other distances from the ground may be made. External beta doses are measured on contact with the source, for example fishing nets, using Mini Instruments^{[footnote 5]}, Smart ION and Electra PB19RD monitors. These portable instruments are calibrated against recognised reference standards, and the inherent instrument background is subtracted. There are 2 quantities that can be presented as measures of external gamma dose rate, total gamma dose rate or terrestrial gamma dose rate. Total gamma dose rate includes all sources external to the measuring instrument. Terrestrial gamma dose rate excludes cosmic sources of radiation but includes all others. In this report, the total gamma dose rate is presented. UKHSA reports terrestrial gamma dose rates to SEPA. Terrestrial gamma dose rate is converted to total gamma dose rate by the addition of 0.037µGy h^-1 which approximates the contribution made by cosmic radiation (Her Majesty’s Inspectorate of Pollution 1995).

Gamma monitoring of radiological contamination on beaches is undertaken, on behalf of SEPA, using similar instrumentation to that for measurements of dose rates. The aim is to cover a large area including strandlines where radioactive debris may become deposited. At Dalgety Bay (Section 7.7) and Dounreay (Section 5.1), in Scotland, and at Sellafield (Section 3.3.3), in Cumbria, special monitoring procedures are in place due to the potential presence of radioactive particles on beaches. Further information regarding Dalgety Bay, Dounreay, and Sellafield is provided elsewhere in this report.

2.3. Presentation of results

The tables of monitoring results contain summarised values of observations obtained during the year under review. The data are generally rounded to 2 significant figures. Values near to the limits of detection will not have the precision implied by using 2 significant figures. Observations at a given location, for activity concentrations and dose rates, may vary throughout the year. This variability may be due to changes in rates of discharge, different environmental conditions and uncertainties arising from the methods of sampling and analysis.

The method of presentation of the summarised results allows the data to be interpreted in terms of public radiation exposures for comparison with agreed safety standards.

For milk samples, the most appropriate quantity for use in assessments is the arithmetic mean in the year sampled from the farm with the highest mean activity concentration. This is labelled ‘max’ in the tables of results to distinguish it from the values that are averaged over a range of farms. For other terrestrial foods, an alternative approach is adopted since it is recognised that the possible storage of foods harvested during a particular time of the year has to be taken into account. Greater public exposures would be observed coincidentally with foods being harvested at times of elevated radiological contamination. For such foods, as well as the mean value, the maximum activity concentration (labelled ‘max’ in the tables) observed for each radionuclide is presented at any time in the relevant year and forms the basis for the assessment of dose.

Results are presented, where a sample is taken or a measurement is made, for each location or source of supply. Sample collectors are instructed to obtain samples from the same location during the year. Spatial averaging is therefore not generally undertaken, though it is inherent in the nature of some collected samples. A fish may move some tens of kilometres in an environment of changing concentrations in seawater, sediments and lower trophic levels. The resulting quantity of radiological contamination therefore represents an average over a large area. Similarly, cows providing milk at a farm may feed on grass and other fodder collected over a distance of a few kilometres of the farm. In the case of dose rate measurements, the position where the measurement is conducted is within a few metres of other measurements made within a year. Each observation consists of the mean of many instrument readings at a given location.

The numbers of farms that were sampled to provide information on activities in milk at nuclear sites are indicated in the tables of results. Milk samples collected weekly or monthly are generally bulked to provide quarterly samples for analysis each year. Otherwise, the number of sampling observations in the tables of concentrations refers to the number of samples that were prepared for analysis during the year. In the case of small animals such as molluscs, one sample may include several hundred individual animals.

The number of sampling observations does not necessarily indicate the number of individual analyses conducted for a specific radionuclide. In particular, determinations by radiochemical methods are sometimes conducted less frequently than those by gamma-ray spectrometry. However, results are often based on bulking of samples such that the resulting determination remains representative.

Only results that are the most relevant for assessing the impact of radionuclide concentrations in food and the environment are provided in each site table. This ensures that reporting of the more meaningful results is manageable. For example, gamma-ray spectrometry can provide many ‘less than values’ and may not be reported. To identify the most relevant values to be included in each individual table, one or more of the following conditions is required:

1. all radionuclide results (both positively detected and ‘less than values’) are reported in the site table if the radionuclide is specified in the relevant permit or authorisation (as indicated for each site in Appendix 1, Table A1.1 and Table A1.2)

2. all radionuclide results (both positively detected and ‘less than values’) are reported that have been analysed using a radiochemistry method (for example, plutonium radionuclides)

3. for any radionuclide that is reported as positively detected in the previous 5 years of annual reporting, all activity concentration data of that radionuclide are reported (they are only excluded from the table after 5 continuous years of reporting ‘less than values’)

4. for any radionuclide that is reported as positively detected in one of the samples, all activity concentration data of that radionuclide are reported for other samples presented in the table (terrestrial and marine) in that year

5. naturally occurring radionuclides measured by gamma-ray spectrometry (for example potassium-40) are not usually reported unless the intention is to establish whether there is any enhancement above the expected background concentrations (for example from landfill sites)

2.4. Detection limits

There are 2 main types of results presented in the tables:

• positively detected values
• values preceded by a ‘less than’ symbol (<)

Where the results are an average of more than one value, and each value is positive, the result is positive.

Alternatively, where there is a mixture of data, or all data are at the limit of detection (LoD) or minimum reporting level, the result is preceded by a ‘less than’ symbol. Gamma-ray spectrometry can provide many ‘less than values’.

Limits of detection are governed by various factors relating to the measurement method used and these are described in earlier reports (Ministry of Agriculture Fisheries and Food 1995). There are also a few results quoted as ‘not detected’ (ND) by the methods used. This refers to the analysts’ judgement that there is insufficient evidence to determine whether the radionuclide is present or absent.

2.5. Additional information

The main aim of this report is to present all the results of routine monitoring from the programmes described previously. However, it is necessary to carry out some averaging for clarity and to exclude some basic data that may be of use only to those with specific research interests. Full details of the additional data are available from the environment agencies and FSA. Provisional results of concentrations of radionuclides in food samples collected in the vicinity of nuclear sites in England, Northern Ireland (milk and canteen meals) and Wales are published on the FSA’s data portal - radiological monitoring.

The main categories of additional data are:

• data for individual samples prior to averaging
• uncertainties in measurements
• data for very short-lived radionuclides supported by longer-lived parents
• data which are not relevant to a site’s discharges for naturally occurring radionuclides and for artificial radionuclides below detection limits
• measurements conducted as part of the research programme described in Appendix 7

Very short-lived radionuclides such as yttrium-90, rhodium-103m, rhodium-106m, barium-137m and protactinium-234m (formed by decay of strontium-90, ruthenium-103, ruthenium-106, caesium-137 and thorium-234, respectively) are taken into account for calculating exposures to members of the public. They are not listed in the tables of results. As a first approximation, their concentrations can be taken to be the same as those of their respective parents. The effects of these short-lived radionuclides are included in the dose coefficients and mean beta and gamma energies (Appendix 5).

In the discussion of changes in discharges, the factors listed below are considered:

• is the change in discharge greater than +/- 10% of the percent of annual limit between years
• has there been an order of magnitude change in the discharges
• has the discharge gone from Nil to a finite value (or vice versa)

2.6. Radiation protection standards

The monitoring results in this report are interpreted in terms of radiation exposures of the public, commonly termed ‘doses’. This section describes the dose standards that apply in ensuring protection of the public. Previous UK practice is described in previous RIFE reports (Environment Agency and others, 2007).

Current UK radiological protection law is retained from the 2013 Basic Safety Standards Directive (European Commission 2014). This EU directive implemented the ICRP’s 2007 general recommendations for a system of radiological protection, set out in ICRP Publication 103 (International Commission on Radiological Protection 2007). The Directive’s requirements were transposed into UK legislation and include dose limits for members of the public, including limits on effective dose and equivalent doses to the skin and lens of the eye. Any changes in UK radiological protection law and standards will be taken into account for future issues of this RIFE report.

The respective national legislative frameworks, which are equivalent, governing radiological protection, including regulation of public exposure to radioactive wastes are described below

• For England and Wales, the requirements are set out in Schedule 23 ‘radioactive substances activities’ of the Environmental Permitting (England and Wales) Regulations 2016 (EPR 16) (United Kingdom - Parliament 2016)
• In Northern Ireland, the Radioactive Substances (Modification of Enactments) Regulations (Northern Ireland) 2018 (RSR 18) (Statutory Rules of Northern Ireland 2018) by amending the Radioactive Substances Act 1993 (RSA 93) (United Kingdom - Parliament 1993).
• in Scotland the requirements are set out in the Environmental Authorisations (Scotland) Regulations 2018 (EASR) (Scottish Government 2018), Schedule 8 ‘radioactive substances activities’. EASR was amended in 2025 to provide an integrated authorisation framework, bringing together the authorisation, procedural and enforcement arrangements relating to water, waste management, industrial activities and radioactive substances.

A guidance document was also published in 2018, providing the scope of and exceptions from the radioactive substances legislation in England, Wales, and Northern Ireland (Department for Business Energy & Industrial Strategy and others, 2018).

To transpose the requirements of Basic Safety Standards Directive 13, the Ionising Radiations Regulations 2017 (IRR 17) (United Kingdom - Parliament 2017) came into force in 2018 (replacing the Ionising Radiations Regulations 1999). The Ionising Radiations Regulations 2017 controls the radiation exposure of workers and the public apart from that resulting from the permitted disposal of radioactive waste, which is regulated by the environment agencies under the various permitting legislation described previously.

The Environment Agency, NRW and SEPA also have broader responsibilities under the Environment Act 1995 (United Kingdom - Parliament 1995) for environmental protection including determining general concentrations of pollution in the environment. The Environment Act 1995, does not apply to Northern Ireland.

The mean annual dose received by the ‘representative person’ is compared with the relevant dose limit. The term ‘representative person’ refers to those people most exposed to radiation. In this report, they are usually members of the public consuming large quantities of locally harvested food (high-rate consumers) or spending long periods of time in locations being assessed for external exposure. The dose limits apply to all age groups. Doses received by an individual will be age dependent because of differences in their physiology, anatomy and dietary habits. The embryo or foetus (prenatal child) can also receive higher doses than its mother. Consequently, doses have been assessed for different age groups; for example, adults, children (10-year-old), infants (1-year-old) and prenatal children, and from this information it is possible to determine which of these age groups receives the highest dose. Each age group is subject to different factors, including, but not limited to physiological development stages, breathing rates, diet, gender, and smoking/non-smoking.

For drinking water, water quality regulations (Scottish Statutory Instruments 2015; Statutory Instruments 2016; Statutory Rules of Northern Ireland 2017; Welsh Statutory Instruments 2018), prescribe the requirements on the quality of water intended for human consumption in respect of radioactive substances and is retained from the 2013 EU Basic Safety Standards Directive (European Commission 2013). These regulations specify threshold values for gross alpha, gross beta, radon, tritium and ‘Indicative Dose’. Above these values, UK regulatory bodies shall assess whether the presence of radioactive substances in drinking water poses a risk to human health that requires action and, where necessary, take remedial action to improve the quality of water to a level which complies with the requirement for the protection of human health from a radiation protection point of view. Drinking water is taken to include bottled waters (spring and drinking).

In situations that present a novel exposure pathway for members of the public, ‘potential’ exposure routes and standards are determined, and these are discussed further in relation to particles of radioactivity (Dale, Robertson & Toner 2008). For contamination known to be due to radioactive particles in the UK, a site-specific assessment is considered in the relevant section of this report.

Accidental releases will be assessed against UK and ICRP standards in emergency situations (Commission of the European Community 1987; International Commission on Radiological Protection 2007). In addition, it is government policy that food intervention levels retained from EU standards will be taken into account for setting discharge limits. Guidelines for radionuclides in foods following accidental radiological contamination for use in international trade has been published by the Codex Alimentarius Commission (Committee on Interagency Research and Policy Coordination Alimentarius Commission 2011).

2.7. Assessment methods

Calculations of exposures to members of the public in this report are primarily based on the environmental monitoring data for the year shown under study. The methods used have been assessed for conformity with the principles endorsed by the UK National Dose Assessment Working Group (Allott 2005), and were found to be compatible (Camplin & Jenkinson 2007). The methods used in RIFE are comparable to those used elsewhere (Johansen and others, 2025). The dose assessment models, PC-CREAM 08® and the Initial Radiological Assessment Tool version 2 have been subjected to thorough intercomparison exercises (Smith & Simmonds 2009; Watson and others, no date). There are 2 types of dose assessment made. The first type gives an estimate of the ‘total dose’ to people around the nuclear sites. It considers the effects of all sources, that is the discharges of gaseous and liquid wastes and direct radiation from sources on the site premises (Camplin and others, 2005). The stages of the assessment are described below.

1. obtain the consumption and occupancy data from habits surveys

2. use the ‘cut-off’ method to group individuals whose consumption or occupancy is within a factor of 3 of the observed maximum

3. habits profiles for the group determined by averaging the habits rates of all individuals in the group

4. repeat steps 2 and 3 for all pathways identified in habits survey (for example, occupancy for direct radiation, milk consumption)

5. doses to each profiled group calculated (using concentrations of radionuclides in food and environmental dose rates). The group with the highest dose near each site becomes the representative person

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The second type of assessment is focused on specific sources of radioactivity and their associated pathways (see Section 1.6 and Appendix 2 in this report for additional information). It serves as a check on the robustness of the ‘total dose’ assessment and is also compatible with the approach used prior to the introduction of ‘total dose’ in 2004.

‘Total dose’ assessments include doses from direct radiation. The estimates of direct radiation dose are provided by The ONR based on information supplied by industry (Coleby 2026). Both types of assessment provide information on 2 other main pathways:

• ingestion of foodstuffs
• external exposure from contaminated materials in the aquatic environment

Collective doses are beyond the scope of this report. They are derived using modelling techniques. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has published an assessment of individual and collective doses to members of the public from exposure to ionising radiation, including nuclear power production and related nuclear fuel cycle facilities and natural sources of ionising radiation (UNSCEAR 2026).

Monitoring data is also used to assess doses from other pathways (Allott 2009) :

• drinking water
• inadvertent ingestion of water and sediments
• inhalation of re-suspended soil and sediment

In addition, models are used to supplement the monitoring data in 3 situations:

• atmospheric dispersion models are used for non-food pathways where monitoring is not an effective method of establishing concentrations or dose rates in the environment. The doses from external exposure and inhalation are included as an hourly dose rate in ‘total dose’ and as an annual dose in the ‘source-specific’ assessments
• food chain models provide additional data to fill gaps and to adjust for high limits of detection
• modelling of exposures of sewage workers is undertaken for discharges from the Atomic Weapons Establishment (AWE) Aldermaston and the Grove Centre, Amersham

Full details of the models used are given in Appendix 3.

For pathways involving intakes of radionuclides, the data required for assessment are:

• concentrations in foodstuffs, drinking water sources, sediments or air
• the amounts eaten, drunk or inhaled
• the dose coefficients that relate an intake or activity to a dose

For external radiation pathways, the data required are:

• the dose rate from the source, for example a beach or fisher’s nets
• the time spent near the source

In both cases, the assessment estimates exposures from these pathways for people who are likely to be most exposed.

2.8. Concentrations of radionuclides in foodstuffs, drinking water sources, sediments and air

In nearly all cases, the concentrations of radionuclides are determined by monitoring and are given in the main text of this report. The concentrations chosen for the assessment are intended to be representative of the intakes of the most exposed consumers in the population. All of the positively determined concentrations tabulated are included irrespective of the origin of the radionuclide. In some cases, this means that the calculated exposures could include contributions due to disposals from other sites as well as from fallout from nuclear weapon testing and activity deposited following a nuclear reactor accident (such as at Chernobyl in 1986). Where possible, corrections for ‘background’ concentrations of naturally occurring radionuclides are made in the calculations of dose (see Section 2.12).

For aquatic foodstuffs, drinking water sources, sediments and air, the assessment is based on the mean concentration near the site in question. For milk, the mean concentration at a nearby farm with the highest individual result is used in the dose assessment. This procedure accounts for the possibility that any farm close to a site can act as the sole source of supply of milk to high-rate consumers.

For other foodstuffs, the maximum activity concentrations are selected for the assessment. This allows for the possibility of storage of food harvested at a particular time when the peak quantities in a year may have been present in the environment.

The tables of activity concentrations include ‘less than values’ as well as positive determinations. This is particularly evident for gamma-ray spectrometry of terrestrial foodstuffs. Where a result is presented as a ‘less than value’, the dose assessment methodology treats it as if it were a positive determination in the following scenarios:

1. when that radionuclide is specified in the relevant permit or authorisation (gaseous or liquid)

2. when that radionuclide was determined using radiochemical methods

3. when a positive result is reported for that radionuclide in another sample from the same sector of the environment at the site (aquatic or terrestrial)

Although this approach may produce an overestimation of dose, particularly at sites where activity concentrations are low, it ensures that estimated exposures are unlikely to be understated.

2.9. Consumption, drinking and inhalation rates

2.9.1. Source-specific assessments

In the assessment of the effects of disposals of liquid effluents, the amounts of fish and shellfish consumed are determined by site-specific dietary habits surveys. Data are collected primarily by direct interviews with potential high-rate consumers who are often found in fishing communities. Children are rarely found to eat large quantities of seafood, and their resulting doses are invariably less than those of adults. The calculations presented in this report are therefore representative of adult seafood consumers or their unborn children if the prenatal children age group is more restrictive.

In assessments of terrestrial foodstuffs, the amounts of food consumed are derived from national surveys of diet and are defined for 3 age groups: adults, children (10-year-old) and infants (1-year-old) (based on (Byrom and others, 1995)). Adult consumption rates are used in the assessment of doses to prenatal children. For each food type, consumption rates at the 97.5^th percentile of consumers have been taken to represent the people consuming a particular foodstuff at a high rate (the consumption rate of the ‘representative person’).

Drinking and inhalation rates are general values for the population, adjusted according to the times spent in the locations being studied.

The consumption, drinking and inhalation rates are given in Appendix 4. Estimates of dose are based on the most up to date information available at the time of writing the report. Where appropriate, the data from site-specific surveys are averaged over a period of 5 years following the recommendation of the report of the consultative exercise on dose assessments (Food Standards Agency 2001).

The assessment of terrestrial foodstuffs is based on 2 assumptions:

• that the foodstuffs eaten by the most exposed individuals are those that are sampled for the purposes of monitoring, see references (Swift 2002; Centre for Environment Fisheries and Aquaculture Science no date) for previous investigations into key marine environmental indicators and uncommon seafoods, respectively
• that the consumption of such foodstuffs is sustained wholly by local sources

The 2 food groups resulting in the highest dose are taken to be consumed at high consumption rates, while the remainder are consumed at mean rates. The choice of 2 food groups at the higher consumption rates is based on statistical analysis of national diet surveys. This shows that only a very small percentage of the population were critical rate consumers in more than 2 food groups (Ministry of Agriculture Fisheries and Food 1996). Locally grown cereals are not considered in the assessment of exposures as it is considered highly unlikely that a significant proportion of cereals will be made into locally consumed (as opposed to nationally consumed) foodstuffs, notably bread.

2.9.2. ‘Total dose’ assessments

The ‘total dose’ assessments are based on consumption and occupancy data collected from site-specific surveys which are targeted at those most likely to be exposed around the site. The habits profiles that give rise to the highest doses in the assessment of RIFE data are given in files that accompany this report and are available from the main RIFE page. Care should be taken in using these data in other circumstances because the profile leading to the highest doses may change if the measured or forecast concentrations and dose rates change.

2.10. Dose coefficients

Dose calculations for intakes of radionuclides by ingestion and inhalation are based on the compendium of dose coefficients taken from ICRP Publication 119 (International Commission on Radiological Protection 2012) and from ICRP 88 (International Commission on Radiological Protection 2001) and National Radiological Protection Board (NRPB) (Health Protection Agency 2008). The ICRP has published part 1 of its revised dose coefficients to members of the public and has completed consultations on parts 2 and 3. UK regulators are currently reviewing these revised values with a view to implementing them in dose assessment calculations (including those in RIFE) at a suitable timescale agreed with DESNZ and other relevant stakeholders.

These coefficients (often referred to as ‘dose per unit intake’) relate the committed dose received to the amount of radioactivity ingested or inhaled. The dose coefficients used in this report are provided in Appendix 5 for ease of reference. Dose coefficients are available for multiple age groups.

The dose assessments include the use of appropriate gut uptake factors (proportion of radioactivity being absorbed from the digestive tract). Where there is a choice of gut uptake factors for a radionuclide, we have generally chosen the one that gives the highest predicted exposure. Where results for total tritium are available, we have assumed that the tritium content is wholly in an organic form. However, we have also considered specific research work of relevance to the foods considered in this report. This affects the assessments for tritium, polonium, plutonium, and americium radionuclides as discussed in Appendix 5.

2.11. External exposure

In the assessment of external exposure, there are 2 factors to consider:

• the dose rate from the source
• the time spent near the source

In the case of external exposure to penetrating gamma radiation, uniform whole-body exposure has been assumed. The radiation as measured is in terms of the primary quantity known as ‘air kerma rate’, a measure of the energy released when the radiation passes through air. This has been converted into exposure using the factor 1milligray = 0.85mSv (International Commission on Radiological Protection 2010). This factor applies to a rotational geometry with photon energies ranging from 50keV to 2MeV. This is appropriate for the instrument used whose sensitivity is much reduced below 50keV, and to the geometry of deposits of artificial radionuclides. Applying an isotropic geometry gives a value of 0.70Sv Gy^-1, which would be more appropriate for natural background radiation. The choice of 0.85 will therefore tend to overestimate dose rates for the situations considered in this report which include both artificial and natural radiation.

For external exposure of skin, the measured quantity is radiological contamination in Bq cm^-2. In this case, dose rate factors in Sv y^-1 per Bq cm^-2 are used, which are calculated for a depth in tissue of 7mg cm^-2 (Kocher & Eckerman 1987). The time spent near sources of external exposure are determined by site-specific habits surveys in a similar manner to consumption rates of seafood. The occupancy and time spent handling fishing gear are given in Appendix 4.

2.12 Subtraction of ‘background’ activity concentrations

For assessing internal exposures in seafood due to the ingestion of carbon-14 and radionuclides in the uranium and thorium decay series, ‘background’ activity concentrations are subtracted. Background carbon-14 concentrations in terrestrial foods are also subtracted. The estimates of background activity concentrations are given in Appendix 6. For assessing the effect of external exposures to gamma radiation, dose rates due to background are subtracted. Since measurements were made previously as part of the monitoring programmes reported here, the gamma dose rate backgrounds in the aquatic environment are taken to be 0.05µGy h^-1 for sandy substrates, 0.07µGy h^-1 for mud and salt marsh and 0.06µGy h^-1 for other substrates. These data are compatible with those presented in (McKay and others, 1995). Where it is difficult to distinguish the result of a dose rate measurement from natural background, the method of calculating exposures based on the concentrations of artificial radionuclides in sediments is used (Hunt 1984). Estimates of external exposures to beta radiation include a component due to naturally occurring (and un-enhanced) sources because of the difficulty in distinguishing between naturally occurring and artificial contributions. Such estimates are therefore conservative, compared with the relevant dose limit that excludes natural sources of radiation.

2.13. Uncertainties in dose assessment

Various methods are used to reduce the uncertainties in the process of the dose estimation of the representative person. These address the following main areas of concern:

• programme design
• sampling and in situ measurement
• laboratory analysis
• description of pathways to humans
• radiation dosimetry
• calculational and presentational error

Quantitative estimation of uncertainties in doses is beyond the scope of this report.

3. Nuclear fuel production and reprocessing

Highlights

• For nuclear fuel production and reprocessing sites assessed in 2025 the ‘total dose’ for the representative person was 51% (or less) of the annual dose limit

Capenhurst, Cheshire

• ‘total dose’ for the representative person was 0.18mSv and decreased in 2025 compared to 2024

Springfields, Lancashire

• ‘total dose’ for the representative person was 0.010mSv and decreased in 2025 compared to 2024

Cumbrian coastal area, including Sellafield, Cumbria

• ‘total dose’ for the Cumbrian coastal community was 0.51mSv and increased in 2025 compared to 2024
• the highest ‘total dose’ was from seafood, dominated by the effects of historical discharges of naturally occurring radionuclides from the former phosphate processing plant. Historical discharges from the Sellafield site made a lesser contribution

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This section considers the results of monitoring, by the Environment Agency, FSA, NIEA and SEPA, of 3 sites in the UK associated with civil nuclear fuel production and reprocessing. Data tables and the detailed results of the dose assessments, in Open Document Spreadsheet (ODS) format, are downloadable from the main RIFE page.

3.1. Capenhurst, Cheshire

The Capenhurst site is located near Ellesmere Port and is home to uranium enrichment plants and associated facilities. The major operators at the site are Urenco UK Limited (UUK), Urenco Nuclear Stewardship Limited (UNS) and Urenco ChemPlants Limited (UCP); they each have their own permits. Urenco UK Limited operates 3 plants producing enriched uranium for nuclear fuel production. Urenco Nuclear Stewardship Limited manages assets owned by the NDA, comprising uranic material storage facilities and activities associated with decommissioning, Urenco Nuclear Stewardship Limited also manage radioactive wastes on behalf of all 3 operators. Urenco ChemPlants Limited are currently commissioning a new facility on a separate part of the site, to allow safer long-term storage of depleted uranium. This facility, the Tails Management Facility, de-converts uranium hexafluoride (UF₆ or “Hex”) to uranium oxide (U₃O₈). This allows the uranium to be stored in a more chemically stable oxide form for potential future reuse in the nuclear fuel cycle. This process recovers hydrofluoric acid for reuse in the chemical industry.

The most recent habits survey to determine the consumption and occupancy rates by members of the public was undertaken in 2021 (Moore, Clyne & Greenhill 2022).

3.1.1. Doses to the public

The ‘total dose’ from all pathways and sources of radiation was 0.18mSv in 2025 (Table 3.1), or 18% of the dose limit to members of the public. This is a decrease from 0.22mSv in 2024 due to a lower estimate of direct radiation, which is the dominant contribution to dose from the site. The representative person was a child living close to the site, unchanged from 2024. The trend in annual ‘total dose’ over the period 2014 to 2025 is given in Figure 3.1. The ‘total dose’ at Capenhurst ranged from 0.13mSv in 2015 to 0.22mSv in 2024 and all were below the dose limit to members of the public. Any changes in annual ‘total dose’ over time were due to changes in the estimates of direct radiation from the site.

Figure 3.1. ‘Total dose’, in mSv y^-1, at Capenhurst, 2014 to 2025.

Year	Dose
50% of the Dose limit	0.50
2014	0.17
2015	0.13
2016	0.17
2017	0.17
2018	0.16
2019	0.17
2020	0.17
2021	0.17
2022	0.14
2023	0.15
2024	0.22
2025	0.18

Source-specific assessments for high-rate consumers of locally grown foods, and for children playing in and around Rivacre Brook, give exposures that were less than the ‘total dose’ in 2025 (Table 3.1). The dose for children (10-year-old), who play in and around the brook and may inadvertently ingest water and sediment, was 0.009mSv in 2025 (up from 0.007mSv in 2024). The increase in dose was due to higher gamma dose rates measured over the riverbank at Rivacre Brook in 2025. The dose is estimated using cautious assumptions for occupancy of the bank of the brook, inadvertent ingestion rates of water and sediment, and gamma dose rates.

3.1.2 Gaseous discharges and terrestrial monitoring

Uranium is the main radioactive constituent of gaseous discharges from Capenhurst (Table A1.1), with small amounts of other radionuclides present in discharges by Urenco Nuclear Stewardship Limited. The focus for terrestrial sampling was the analyses of technetium-99 and uranium in food (including milk), grass and soil. Results for 2025 are given in Table 3.2(a). Concentrations of radionuclides in milk and food samples around the site were very low and generally similar to those in previous years. Isotopes of uranium in silage were lower by small amounts (most likely due to natural variation) in 2025. Figure 3.2(a) shows the trends over time (2014 to 2025) of low technetium-99 discharges and corresponding technetium-99 concentrations in grass. The overall trend reflects the reductions in discharges of technetium-99 from the enrichment of reprocessed uranium in the past. The most recently observed variability (from year to year) in the technetium-99 concentrations is based on data reported as ‘less than values’. Discharges of uranium in 2025 are also given in Table A1.1 and were similar to those reported in 2024. Long term plots of uranium discharges are given in (OSPAR 2023).

Figure 3.2. Technetium-99 concentrations in grass, in Bq kg^-1 (fresh), and annual discharges, in MBq y^-1 at Capenhurst, 2014 to 2025. (Note different scales used for discharges and activity concentrations).

3.1.3 Liquid waste discharges and aquatic monitoring

The permit for the Urenco UK Limited Capenhurst site allows liquid waste discharges to the Rivacre Brook for uranium and uranium daughters, technetium-99 and non-uranium alpha (mainly neptunium-237) as shown in Table A1.2. Monitoring included the collection of samples of fish and shellfish from the local aquatic and downstream marine environment (for analysis of a range of radionuclides) and of freshwater and sediments for the analysis of tritium, technetium-99, gamma-emitting radionuclides, uranium, neptunium-237, and gross alpha and beta. Dose rate measurements were taken on the banks of the Rivacre Brook and surrounding area. Results for 2025 are given in Table 3.2(a) and Table 3.2(b). Concentrations of radionuclides in foods from the marine environment were very low and generally similar to those in previous years. The concentrations in fish and shellfish reflect the distant effects of discharges from Sellafield as observed in previous monitoring reports, such as the ‘Radioactivity in surface and coastal waters of the British Isles’ reports (published as part of the Fisheries Radiobiological Laboratory report and Aquatic Environment Monitoring Report series) and earlier RIFE reports.

As in previous years, sediment samples collected downstream from the Rivacre Brook contained very low but measurable concentrations of uranium (enhanced above natural concentrations) and technetium-99. As expected, enhanced concentrations of these radionuclides (and others) were measured close to the discharge point (Rivacre Brook). Technetium-99 and uranium radionuclide concentrations from this location were lower in 2025, compared to 2024, but similar to those in other recent years. Variations in concentrations in sediment from the brook are also to be expected due to differences in the size distribution of sedimentary particles. Concentrations of radionuclides in freshwaters at the discharge point (and at other freshwater locations) were very low in 2024. Measured gamma dose rates near to the discharge point were higher in 2025, compared to 2024 (where comparisons can be made for similar ground types and locations). Downstream of the discharge point (Rivacre Brook), at the location where children play, dose rates over grass were also higher in 2025.

Concentrations of technetium-99 from liquid discharges were detectable in sediment from Rivacre Brook close to the discharge point in 2025. The trend of technetium-99 in sediment is given in Figure 3.3; concentrations in 2017 were higher than adjoining years as discussed in RIFE 23 (Environment Agency and others, 2018).

Figure 3.3. Technetium-99 concentrations in sediment in Bq kg^-1 (dry) at Rivacre Brook, Capenhurst, 2014 to 2025.

Year	99Tc concentration Bq Kg-1 (dry)
2014	120
2015	92
2017	530
2018	69
2019	190
2020	270
2021	250
2022	250
2023	150
2024	42
2025	250

Concentrations of caesium-137 and americium-241 in sediments at Rock Ferry (Figure 3.4) on the Irish Sea coast were from past discharges from Sellafield carried into the area by tides and currents. The concentrations were generally similar over most of the time period and any fluctuations were most likely due to the effects of normal dispersion in the environment. The lowest activity concentrations at Rock Ferry were reported in 2016.

Figure 3.4. Caesium-137 and americium-241 concentrations in sediment in Bq kg^-1 (dry) at Rock Ferry, 2014 to 2025.

3.2. Springfields, Lancashire

The Springfields site near Preston is operated by Springfields Fuels Limited (SFL). The site is owned by the NDA and leased to Westinghouse Electric Company UK Limited, the parent company of Springfields Fuels Limited (SFL). The main commercial activity is the manufacture of fuel elements for nuclear reactors and the deconversion of uranium hexafluoride to produce powders and pellets for other fuel manufacturers. Other important activities include recovery of uranium from residues and decommissioning redundant plants and buildings, under contract to the NDA, who retain responsibility for the historical nuclear liabilities on the site.

Research and development, carried out by the UK National Nuclear Laboratory (UKNNL), produces small amounts of other gaseous radionuclides that are also discharged under the permit (see Appendix 1, Table A1.1).

Monitoring around the site is carried out to check not only for uranium concentrations, but also for other radionuclides discharged in the past (such as actinide decay products from past discharges when uranium ore concentrate (UOC) was the main feed material) and for radionuclides discharged from Sellafield. The monitoring locations (excluding farms) are shown in Figure 3.5. The corresponding sample types and locations are listed in the corresponding site tables.

Figure 3.5. Monitoring locations at Springfields, 2025 (not including farms).

The most recent habits survey was undertaken in 2022 (Clyne and others, 2023). Figures for consumption rates, together with occupancy and handling rates, are provided in Appendix 4 (Table A4.2).

3.2.1. Doses to the public

The ‘total dose’ from all pathways and sources of radiation was 0.010mSv in 2025 (Table 3.1), or 1% of the dose limit to members of the public. This is a decrease from 0.017mSv in 2024 and mainly attributed to a lower estimate of direct radiation from the site. In 2025, the representative person was an infant living near to the site and unchanged from 2024. Most of the dose to the representative person was from direct radiation. The trends of ‘total dose’ over the period 2014 to 2025 are given in Figure 3.6 and are generally low over this period, the increase observed in 2019 was due to a higher estimate of direct radiation caused by increased occupancy of some workers undertaking a specific responsibility (associated with the rail line) close to the site.

Source-specific assessments give exposures that were all less than the ‘total dose’ in 2025 (Table 3.1) for:

• consumers of locally grown food and of seafood (including wildfowl)
• farmers spending time on the banks of the estuary
• children playing on the banks of the estuary

Trends in source-specific doses for a high-rate houseboat dweller are presented in earlier RIFE reports.

Figure 3.6. ‘Total dose’, in mSv y^-1, at Springfields (2014 to 2025).

Year	Dose
50 % of the Dose limit	0.50
2014	0.050
2015	0.050
2016	0.038
2017	0.028
2018	0.075
2019	0.14
2020	0.047
2021	0.031
2022	0.032
2023	0.040
2024	0.017
2025	0.010

The dose for high-rate consumers of seafood and wildfowl was 0.008mSv in 2025, with approximately 0.006mSv from external exposure (the remainder being from consumption of fish, crustaceans and wildfowl) and was similar to that in 2024 (0.009mSv). The most important radionuclide was caesium-137 from historical discharges from Sellafield.

A source-specific assessment for external exposure to farmers was less than 0.005mSv in 2025 (Table 3.1) and unchanged from 2024. The estimated doses to high-rate consumers of locally grown food, and to children playing on the banks of the estuary were all less than 0.005mSv in 2025.

It has been previously shown that assessed annual doses to the public from inhaling sediment from the Ribble Estuary, re-suspended into the air, were much less than 0.001mSv, and negligible in comparison with other exposure routes (Rollo and others, 1994).

3.2.2 Gaseous discharges and terrestrial monitoring

Uranium is the main radioactive constituent of gaseous discharges, with small amounts of other radionuclides present in discharges from UK National Nuclear Laboratory research and development facilities (Table A1.1).

The focus of the terrestrial sampling was for the analyses of tritium, carbon-14, strontium-90, iodine-129, and isotopes of uranium, thorium, plutonium and americium in milk and vegetables. Grass, soil and freshwater samples were collected and analysed for isotopes of uranium. Data for 2025 are given in Table 3.3(a). Uranium isotope concentrations in beetroot in 2025 were similar to those in pumpkin in 2024 (no beetroot sample was available in 2024). Concentrations of thorium were also low in vegetable and grass samples. As in previous years, elevated concentrations of uranium isotopes were measured in soils around the site, but the isotopic ratio showed that they were most likely to be naturally occurring. Overall, results were broadly similar to those of previous years.

Figure 3.7 shows the trends over time (2014 to 2025) of gaseous uranium discharges and total uranium radionuclide concentrations in food (beetroot; 2014 to 2023; pumpkin 2024; beetroot 2025). Over the period, uranium discharges have declined, with the lowest value reported from this site in 2022. Total uranium was detected in beetroot and pumpkin samples during the period, as given in Figure 3.7, but the concentrations were very low. The apparent peak of uranium in beetroot in 2017 was also low and significantly less than that found in soil samples.

Figure 3.7. Concentrations of total uranium in terrestrial food, in Bq kg^-1 (fresh) and annual discharges of uranium, in MBq y^-1 at gaseous Springfields 2014 to 2025. (Note different scales used for discharges and activity concentrations).

3.2.3 Liquid waste discharges and aquatic monitoring

Permitted discharges of liquid waste (including gross alpha and beta, technetium-99, thorium-230, thorium-232, neptunium-237, uranium and ‘other transuranic radionuclides’) are made from the Springfields site to the Ribble Estuary via 2 pipelines (Table A1.2). All discharges were generally similar in 2025, compared to 2024. Compared to previous years, discharges are now generally lower for beta-emitting radionuclides. This includes the short half-life beta-emitting radionuclides (mostly thorium-234) that have decreased following the end of the uranium ore concentrate purification process in 2006. Production of uranium hexafluoride ceased in 2014, and the associated plants mothballed. This has led to a corresponding reduction in discharges of uranium in recent years. Discharges of technetium-99 depend almost entirely on which legacy uranic residues are being processed. Since completion of one particular residue processing campaign (in 2012), technetium-99 discharges (Figure 3.8) have generally declined, with the lowest value (reported as <1% of the annual limit) from this site in 2024. The Ribble Estuary monitoring programme consisted of ‘in situ’ dose rate measurements, the collection and analysis of sediments for uranium and thorium isotopes and gamma-emitting radionuclides.

Figure 3.8. Concentrations of technetium-99 in shrimp, in Bq kg^-1 (fresh) and annual discharges of technetium-99, in GBq y^-1 at Springfields 2014 to 2025. (Note different scales used for discharges and activity concentrations).

Results for 2025 are shown in Table 3.3(a). As in previous years, radionuclides due to discharges from both Springfields and Sellafield were detected in sediment and biota in the Ribble Estuary. Radionuclides found in the Ribble Estuary originating from Sellafield were technetium-99, caesium-137 and americium-241. Isotopes of uranium and the short half-life radionuclide thorium-234 were also found from Springfields. Concentrations of the latter were closely linked to recent discharges from the Springfields site. In 2025, thorium-234 concentrations in sediments (over the range of sampling sites) were generally similar compared to those in 2024. Over a much longer timescale these concentrations have declined due to reductions in discharges as shown by the trend of sediment concentrations at the outfall (Figure 3.9), Lower Penwortham and Becconsall (Environment Agency and others, 2018). The most significant change in the discharge trends was the step reduction of short half-life beta-emitting radionuclides in liquid discharges, mostly thorium-234. The reduction was because the uranium ore concentrate purification process ended in 2006. In more recent years, thorium-234 concentrations have generally declined by small amounts in sediments at Lower Penwortham (Figure 3.10) and Becconsall (Figure 3.11), with the lowest values reported at Lower Penwortham and the outfall in 2023.

Figure 3.9. Concentrations of caesium-137, thorium-234 and americium-241 in sediment, in Bq kg^-1 (dry), at the outfall, Springfields 2014 to 2025.

Figure 3.10. Concentrations of caesium-137, thorium-234 and americium-241 in sediment, in Bq kg^-1 (dry), at Lower Penwortham Park, Springfields 2014 to 2025.

Figure 3.11. Concentrations of caesium-137, thorium-234 and americium-241 in sediment, in Bq kg^-1 (dry), at Becconsall, Springfields 2014 to 2025.

Caesium-137 and americium-241 radionuclides were detected in biota and sediments from the Ribble Estuary in 2025, due to historical liquid discharges from Sellafield, carried from west Cumbria into the Ribble Estuary by sea currents and adsorbed on fine-grained muds. The concentrations observed were generally similar to those in recent years.

Figure 3.8 and Figure 3.12 also provide trend information over time (2014 to 2025) for several other permitted radionuclides and activity concentrations in food, flounder and shrimp. Liquid discharges of uranium radionuclides steadily decreased (and other discharges to a lesser extent) over the whole period, whilst technetium-99 discharges generally decreased overall (but peaked in 2012 and 2017). Caesium-137 concentrations in flounder showed variations between years and this was most likely due to natural changes in the environment, although there is evidence of decreasing concentrations overall (Environment Agency and others, 2025). Technetium-99 concentrations in shrimp showed variations between years and this was most likely due to natural changes in the environment, with lower concentrations observed as discharges have decreased in recent years.

Figure 3.12. Concentrations of caesium-137 in flounder, in Bq kg^-1 (fresh) at Springfields 2014 to 2025.

Year	137Cs Concentration Bq Kg-1 (fresh)
2014	3.2
2015	2.3
2016	2.1
2017	2.0
2018	2.3
2019	2.1
2020	1.7
2021	1.5
2022	1.7
2023	1.1
2024	1.3
2025	1.2

Gamma dose rates (Table 3.3(b)) in the estuary were generally higher than expected natural background rates (see Section 2.12), due to discharges of gamma-emitting radionuclides (caesium-137 and americium-241) from Sellafield. In 2025, gamma dose rates in the estuary, were generally higher (by small amounts) to those in 2024, but with some small variations at some sites. Beta dose rates over salt marsh (where comparisons can be made) were similar to those in recent years.

3.3. Cumbrian coastal area including Sellafield, Cumbria

This section considers both historic and present activities in the Cumbrian coastal area that have led to discharges of radioactive waste, including Sellafield where a range of decommissioning and waste management activities are carried out.

The area is impacted by several sources of radioactivity, these are:

• Naturally occurring radionuclides from historical discharges from the former phosphate processing plant
• Artificial radionuclides from both historical and current discharges from Sellafield to both the marine and terrestrial environments
• Liquid discharges from LLWR
• Direct radiation from Sellafield
• Direct radiation from LLWR

The discharges impact upon the same area, therefore this section presents a dose to the Cumbrian Coastal Community from all sources. A separate assessment of doses from Sellafield only is also presented. Separate assessments for LLWR and the former phosphate processing plant are given in Sections 7.1 and 7.5 respectively.

The former phosphate processing plant which closed in 2004 was near Whitehaven in Cumbria. Although phosphoric acid production at the plant ceased in 1992, with a corresponding reduction in discharges to the Irish Sea (Rollo and others, 1992), the effects of these past operations continue due to the ingrowth of decay products from the long-lived parent radionuclides discharges by the plant to the Irish Sea. Naturally occurring radionuclides from this historic industrial activity are monitored and assessed (see Section 7.5).

Sellafield Limited is responsible for the operation of the Sellafield site and is a wholly owned subsidiary of the NDA. In 2025, the main operations at Sellafield were:

• post-operational clean out at the Magnox reprocessing facility
• the decommissioning and clean-up of redundant nuclear facilities including Calder Hall nuclear power station, Windscale reactors and the Thermal Oxide Reprocessing Plant (THORP)
• waste treatment and storage of radioactive materials

Nuclear fuel reprocessing at THORP and the Magnox reprocessing facility ceased in 2018 and 2022 respectively, Resulting in reduced gaseous and liquid discharges in the intervening period. THORP will continue to serve the UK until the 2070/80s as a storage facility for spent Advanced Gas-cooled Reactor (AGR) fuel pending disposal to a new geological disposal facility. The Magnox Reprocessing facility has now entered the post-operational clean-out phase.

Monitoring of the environment and food in the Cumbrian Coastal area including around Sellafield reflects the historical and current activities the components of the programme are considered here in depth. The discussion is provided in 4 sub-sections, relating to the assessment of dose, the effects of gaseous discharges, the effects of liquid discharges and unusual pathways of exposure identified around the site.

A full habits survey is conducted every 5 years around the Cumbrian coastal area in the vicinity of the Sellafield site, which investigates the exposure pathways relating to current and historical liquid and gaseous discharges, and to direct radiation. Annual review surveys are also undertaken between the full habits surveys that investigate the pathways relating to liquid discharges, review high-rate fish and shellfish consumption by local people and review their intertidal occupancy rates. The most recent full Sellafield habits survey was conducted in 2023 (Moore and others, 2024a). A full survey around the LLWR was also performed in 2023 (Moore and others, 2024b). In 2025, some changes were found in the amounts (and mixes) of seafood species consumed and intertidal occupancy rates (Moore, Clyne, Greenhill & Wylie 2026). Revised figures for consumption rates, together with occupancy rates, are provided in Appendix 4 (Table A4.2). Further afield, the most recent habits surveys were conducted to determine the consumption and occupancy rates by members of the public on the Dumfries and Galloway coast in 2024 (available upon request from SEPA by emailing RSEnquiries@sepa.org.uk) and around Barrow and the south-west Cumbrian coast in 2025 (Greenhill and others, 2026). The results of these surveys are used to determine the potential exposure pathways, related to liquid discharges from Sellafield.

Habits surveys to obtain data on activities undertaken on beaches relating to potential public exposure to radioactive particles in the vicinity of the Sellafield nuclear site were undertaken in 2007 and 2009 (Clyne and others, 2008; Clyne and others, 2010).

3.3.1. Doses to the Cumbrian coastal community

The doses calculated in this section cover a wide area and consider the inputs from several sources:

• naturally occurring radionuclides from the non-nuclear activity from the former phosphate processing plant in Whitehaven
• artificial radioactivity from both historical and current discharges from Sellafield to both the marine and terrestrial environments
• sources of direct radiation from Sellafield
• liquid discharges from the LLWR
• sources of direct radiation from the LLWR

Liquid discharges from Wylfa, Chapelcross, Barrow and Heysham also have a very small impact on doses but are not considered in this section.

3.3.1.1. ‘Total dose’ from all pathways and sources to the Cumbrian coastal community

In 2025, the highest ‘total dose’ to the Cumbrian coastal community, near Sellafield, was assessed to have been 0.51mSv^{[footnote 6]} (Table 3.16), or 51% of the dose limit to members of the public. The dose is broken down as follows:

• 0.49mSv from historical discharges of naturally occurring radionuclides from the former phosphate processing plant at Whitehaven, an increase from 0.18mSv in 2024
• 0.020mSv from discharges of artificial radionuclides (including external radiation) from Sellafield, a small increase from 0.018mSv in 2024. Approximately 0.003mSv of this was from sources of direct radiation from the LLWR

This is an increase from 0.20mSv in 2024, which is mostly attributed to higher polonium-210 concentrations in crabs (at Parton) and to a lesser extent an increase in the crustacean consumption rate. Polonium-210 (and lead-210) are important radionuclides as small changes in concentrations above the natural background of these radionuclides, significantly influence the dose contribution from these radionuclides (due to a relatively high dose coefficient used to convert an intake of radioactivity into a radiation dose) and therefore the value of the estimated dose. The assessment is cautious as the liquid discharges from all sites go into the same area.

The representative person was an adult consuming crustacean shellfish at high rates who also consumed significant quantities of other seafood (fish) and was unchanged from 2024. The annual ‘total dose’ from all pathways and sources of radiation is assessed using consumption and occupancy data from the full habits survey of 2023 (Moore and others, 2024b) and the yearly review of shellfish and fish consumption, and intertidal occupancy in 2025 (Moore, Clyne, Greenhill & Wylie 2026). Calculations are performed for 4 age groups (adults, 10-year-old children, 1-year-old infants and prenatal children).

The most significant pathway contributions^{[footnote 7]} to the ‘total dose’ in 2025 were from crustacean consumption (97%), fish consumption (1%), direct radiation (from the LLWR) (<1%) and external exposure over intertidal substrates (<1%) and other pathways (<1%). The listed food groups are consumption pathways; the other pathways include external exposure over sediment and saltmarsh. The most important radionuclide was polonium-210 (contributing 95% of the dose) with transuranic radionuclides (including plutonium-239+240 and americium-241) contributing less than 2% of the dose.

The contributions from artificial radionuclides from Sellafield (0.020msv in 2025) to the ‘total dose’ were mostly americium-241 (33%), iodine-129 (28%, based on concentrations reported at the limit of detection), and plutonium radionuclides (6%). External exposure contributed 27% of the ‘total dose’ from artificial radionuclides (48% in 2024).

Contributions to the highest annual ‘total dose’ each year (2014 to 2025), from all pathways and sources by industry, are given in Figure 3.13. Inter-annual variations were more complex and governed by both natural variability in seafood concentrations and real changes in the consumption and occupancy characteristics of the local population. Over a longer period, the trend is of generally declining dose (Environment Agency and others, 2018). From 2014, the relative changes in dose were largely due to variations in polonium-210 concentrations in locally caught lobsters and crabs.

Figure 3.13. Contributions from the nuclear industry (Sellafield and the LLWR) and the former phosphate processing plant to ‘total dose’, in mSv y^-1, from all sources assessed along the Cumbrian Coast, 2014 to 2025.

Year	Dose from the Nuclear Industry (Sellafield and the LLWR), mSv y-1	Dose from the Former phosphate processing plant at Whitehaven, mSv y-1	Total, mSv y-1
2014	0.068	0.15	0.22
2015	0.078	0.35	0.42
2016	0.074	0.34	0.42
2017	0.077	0.18	0.25
2018	0.034	0.33	0.37
2019	0.055	0.20	0.25
2020	0.058	0.25	0.31
2021	0.019	0.19	0.21
2022	0.014	0.22	0.24
2023	0.019	0.21	0.23
2024	0.018	0.18	0.20
2025	0.020	0.49	0.51

The contributions from all pathways and sources to the highest annual ‘total dose’ from the nuclear industry (primarily Sellafield), from external exposure and ingestion or inhalation of radionuclides, and by radionuclide, are also given in Figure 3.14 (2014 to 2025) and Figure 3.15 (2014 to 2025), respectively. The overall trend from the nuclear industry is a generally declining dose (Figure 3.14), broadly reflecting a general reduction of concentrations of artificial radionuclides in seafood from the nuclear industry discharges and changes in habits information, over this period. The pathways of exposure contributing the highest dose were consumption of mollusc, crustacean and sea fish.

Figure 3.14. Contributions from nuclear industry (external exposure, and ingestion and inhalation doses), primarily from Sellafield to ‘total dose’, in mSv y^-1, from all sources assessed along the Cumbrian Coast, 2014 to 2025.

Year	Dose from external exposure, mSv y-1	Dose from ingestion and inhalation of radionuclides, mSv y-1	Total, mSv y-1
2014	0.017	0.052	0.068
2015	0.017	0.061	0.078
2016	0.019	0.055	0.074
2017	0.016	0.061	0.077
2018	0.0043	0.030	0.034
2019	0.018	0.037	0.055
2020	0.015	0.044	0.058
2021	0.0027	0.016	0.019
2022	0.0027	0.011	0.014
2023	0.012	0.0075	0.019
2024	0.0088	0.0096	0.018
2025	0.0054	0.015	0.020

Figure 3.15. Radionuclide contributions from the ingestion and inhalation of radionuclides from nuclear industry to ‘total dose’, in mSv y^-1, from all sources assessed along the Cumbrian Coast, 2014 to 2025

Year	Doses from 129I, mSv y-1	Doses from 99Tc, mSv y-1	Doses from 137Cs, mSv y-1	Dose from Pu isotopes, mSv y-1	Dose from 241Am, mSv y-1	Doses from other artificial radionuclides, mSv y-1	Total, mSv y-1
2014	0.0028	0.00068	0.0026	0.014	0.026	0.0059	0.052
2015	0.012	0.0012	0.0022	0.014	0.026	0.0063	0.061
2016	0.010	0.00097	0.0024	0.013	0.021	0.0071	0.055
2017	0.012	0.0012	0.0023	0.013	0.027	0.0055	0.061
2018	0.0088	0.00074	0.0019	0.0036	0.011	0.0036	0.030
2019	0.0054	0.00073	0.0012	0.010	0.017	0.0028	0.037
2020	0.0086	0.00072	0.0011	0.011	0.020	0.0030	0.044
2021	0.0042	0.00034	0.00044	0.0014	0.0087	0.0011	0.016
2022	0.0041	0.00026	0.00037	0.00083	0.0044	0.00096	0.011
2023	0.0029	0.00013	0.00041	0.00054	0.0029	0.00060	0.0075
2024	0.0027	0.000082	0.00021	0.00072	0.0051	0.00075	0.0096
2025	0.0056	0.00015	0.00050	0.0012	0.0066	0.00073	0.015

Other age groups in the Cumbrian Coastal Community received less exposure than the adults ‘total dose’ of 0.51mSv in 2025 (10-year-old children: 0.27mSv; 1-year-old infants: 0.18mSv; prenatal children: 0.063mSv). The contributors to the other age groups are similar to those for the overall ‘total dose. The ‘total dose’ estimated for each age group may be compared with the average dose of approximately 2.2mSv to members of the UK population from exposure to natural radiation in the environment UKHSA UK ionising radiaton (UK Health Security Agency no date) and to the annual dose limit to members of the public of 1mSv.

3.3.1.2. ‘Total dose’ from all pathways and sources in the vicinity of the Sellafield site

The annual ‘total dose’ from all pathways and sources of radiation is assessed using consumption and occupancy data from the full habits survey of 2023 (Moore and others, 2024a) and the yearly review of shellfish and fish consumption, and intertidal occupancy in 2025 (Moore, Clyne, Greenhill & Wylie 2026). Calculations are performed for 4 age groups (adults, 10-year-old children, 1-year-old infants and prenatal children).

The highest total dose for a local high-rate seafood consumer was assessed to have been 0.51mSv in 2025, or approximately 51 per cent of the dose limit to members of the public (Table 3.16). This dose is broken down as follows:

• 0.49mSv from historical discharges of naturally occurring radionuclides from the former phosphate processing plant at Whitehaven, an increase from 0.18mSv in 2024
• 0.018mSv from discharges of artificial radionuclides (including external radiation) from Sellafield, an increase from 0.012mSv in 2024. 0.0003mSv of this was from sources of direct radiation from Sellafield (the ‘representative person’ only receives a portion of the annual direct radiation dose of 0.003mSv)

The representative person was an adult consuming crustacean shellfish at high rates who also consumed significant quantities of other seafood (fish). The increase from 0.19mSv in 2024, which was mostly attributed to higher polonium-210 concentrations in crabs (at Parton) and to a lesser extent an increase in the crustacean consumption rate.

The most significant contributions were from crustacean consumption (98%), fish consumption (1%) and other pathways (<1%). The listed food groups are consumption pathways the other pathways include external exposure over sediment. The most important radionuclide was polonium-210 from historical discharges of naturally occurring radionuclides from the former phosphate processing plant (96%) with transuranic radionuclides (including plutonium-239+240 and americium-241) contributing approximately 2% of the dose.

The dose in 2025 from artificial radionuclides discharged by Sellafield (including external radiation) and from historical discharges of naturally occurring radionuclides (from the former phosphate processing plant at Whitehaven) contributed 0.018mSv and 0.49mSv, respectively. Data for naturally occurring radionuclides in fish and shellfish, and their variation in recent years, are discussed in Section 7.5.

The contribution to the ‘total dose’ of 0.018mSv in 2025 from artificial radionuclides (including external radiation) was higher, in comparison to that in 2024 (0.012mSv). This was mostly attributed to update of habits information, in particular the increase in consumption rates of crustacean species. The contributing radionuclides to the dose from artificial radionuclides from Sellafield in 2025 were mostly americium-241 (37%), iodine-129 (31%, based on results at the analytical limit of detection), other radionuclides (including carbon-14 and caesium-137) (8%) and plutonium radionuclides (7%). External exposure contributed 18% of the ‘total dose’ from artificial radionuclides (10% in 2024).

Other age groups received less exposure than the adults ‘total dose’ of 0.51mSv in 2025 (10-year-old children: 0.27mSv; 1-year-old infants: 0.18mSv; prenatal children: 0.12mSv). The contributors to the other age groups are similar to those for the overall ‘total dose, except the ‘total dose’ to prenatal children, which is due to consumption of game meat, which has a high consumption rate of poultry. The ‘total dose’ estimated for each age group may be compared with the dose of approximately 2.2mSv to members of the UK population from exposure to natural radiation in the environment (UKHSA UK ionising radiation) (UK Health Security Agency no date) and to the annual dose limit to members of the public of 1mSv.

3.3.1.3. ‘Total dose’ from gaseous discharges and direct radiation in the vicinity of the Sellafield site

The annual ‘total dose’ from pathways related to gaseous discharges and sources of direct radiation is assessed by determining the highest dose to all combinations of these pathways. Once the representative person has been identified, the contributions from all other pathways are then included.

Therefore, the representative person for the gaseous discharge pathway may also receive a dose contribution from consumption of seafood and intertidal occupancy.

The highest total dose from pathways related to gaseous discharges and sources of direct radiation in the vicinity of Sellafield was assessed to have been 0.30mSv in 2025, or approximately 30% of the dose limit to members of the public (Table 3.16). This is made up of:

• 0.26mSv from discharges of artificial radionuclides (including external radiation) from Sellafield, an increase from 0.036mSv in 2024
• 0.040mSv from historical discharges of naturally occurring radionuclides in seafood from the former phosphate processing plant, an increase from 0.009mSv in 2024

This is an increase from 0.046mSv in 2024. The most exposed profile and age group in 2025 was an adult who consumed game meat, who also consumed sea fish and spent time over intertidal substrates and a change from 2024 (adult freshwater fish consumer). The increase from 0.046mSv was attributed to high concentrations of caesium-137 in wild wood pigeon (~1600Bq kg^-1) observed in 2025, discussed in Section 3.3.3.12. The profile selection is based upon which individual (derived from habits surveys) receives the highest dose from pathways related to the gaseous discharges and direct radiation from the Sellafield site. In this case, the habits of the game consumers, had the highest consumption rate of poultry, which is the dominant pathway. After selection all pathways are re-included in the assessment, including aquatic pathways (see Section 1.6.1).

The pathway contributors in 2025 to the ‘total dose’ for adults were from consumption of poultry (85%), consumption of crustaceans (13%) and consumption of sea fish (1%)

3.3.1.4. ‘Total dose’ from liquid discharges in the vicinity of the Sellafield site

The people receiving the highest ‘total dose’ from the pathways predominantly relating to liquid discharges are given in Table 3.16. Each ‘total dose’ is the same as that giving their maximum ‘total dose’ for all sources and pathways.

3.3.1.5. Source-specific doses

Doses from important routes of exposure resulting from radioactive waste discharges from Sellafield were estimated using source-specific assessments, and the results of these are given in Table 3.15 and Table 3.16. As in recent years, the sources of highest potential exposure were high-rate consumption of seafood, and external exposure from gamma rays over long periods. Other pathways were kept under review, particularly the potential for sea to land transfer at the Ravenglass Estuary to the south of the site, exposure from contact with beta-emitting radionuclides during handling of sediments and/or handling of fishing gear and from gaseous discharges, and the high-rate consumption of locally grown food.

Doses from terrestrial food consumption

In 2025, adults consuming poultry at high rates and exposed to external and inhalation pathways from gaseous discharges received the highest dose for all ages. The estimated dose was 0.64mSv in 2025 (Table 3.16), or 64% of the dose limit to members of the public and up from 0.010mSv in 2024. Other age groups were less exposed than the adults (10-year-old children: 0.25mSv; infants: 0.12mSv, prenatal children: 0.29mSv).

Doses from seafood consumption

Two sets of habits data are used in these dose assessments. One is based on the habits information seen in the area each year (2025 habits survey). The second is based on a 5-year rolling average using habits data gathered from 2021 to 2025. Some changes were found in the amounts (and mixes) of species consumed compared to those in the 2025 and the 2021 to 2025 rolling average. For crustaceans (crab and lobster, and other crustaceans), the total consumption rate increased in the 2025 habits survey and in the 2021 to 2025 rolling average data. For fish (cod, other fish), the total consumption rate increased in both the 2025 habits survey and in the 2021 to 2025 rolling average data. For molluscs (winkles and other molluscs), the total consumption rates remained the same in the 2024 habits and decreased in the 2021 to 2025 rolling average data. The occupancy rate over sediments increased in the 2024 habits information and decreased in the 2021 to 2025 rolling average. The revised habits data are given in Appendix 4 (Table A4.2).

Aquatic pathway habits are normally the most important in terms of dose near Sellafield and are surveyed every year (for example Moore, Clyne, Greenhill & Wylie 2026). This allows generation of a unique yearly set of data and also rolling 5-year averages. The rolling averages are intended to smooth the effects of sudden changes in habits and provide an assessment of dose that follows more closely changes in radioactivity concentrations in food and the environment. These are used for the main assessment of doses from liquid discharges and follow the recommendations of the report of the consultative exercise on dose assessments (Food Standards Agency 2001).

Table 3.16 summarises source-specific doses to seafood consumers in 2025. The doses from artificial radionuclides to people who consume a large amount of seafood were 0.032mSv (0.030mSv in 2024) and 0.034mSv (0.040mSv in 2024) using the annual and 5-year rolling average habits data, respectively. These doses each include a contribution due to external radiation exposure over sediments.

The dose to a high-rate consumer of seafood, due to the naturally occurring radionuclides resulting from historical discharges from the former phosphate works (using maximising assumptions for the dose coefficients and the 5-year rolling average habits data), is estimated to have been 0.41mSv in 2025, and up from 0.27mSv in 2024. Most of this was due to polonium-210 (99%). For comparison (with the assessment using the 5-year rolling average habits data), the dose from the single-year assessment for the Cumbrian coastal community seafood consumer from naturally occurring radionuclides (based on consumption rates and habits survey data in 2025) was 0.56mSv (Table 3.16).

Taking artificial and enhanced natural radionuclides together, the source-specific doses were 0.59mSv and 0.44mSv for the annual and 5-year rolling average habits data, respectively. These estimates are slightly higher or similar than the estimate of ‘total dose’ from all sources of 0.51mSv. The main reason for this is a difference in the approach to selecting consumption rates for seafood for the representative person. The differences in dose are expected and are within the uncertainties in the assessments (see Section 2.13).

Exposures typical of the wider communities associated with fisheries in Whitehaven, Dumfries and Galloway, the Morecambe Bay area, Northern Ireland and North Wales have been kept under review in 2025 (Table 3.15). Those for fisheries in the Isle of Man and Fleetwood have been shown to be generally lower and dose data are available in earlier RIFE reports (for example Environment Agency and others, 2014). Where appropriate, the dose from consumption of seafood is summed with a contribution from external exposure over intertidal areas. The doses received in the wider communities were significantly lower than for the Cumbrian coastal community because of the lower concentrations and dose rates further afield. There were generally small changes in the doses (and contribution to doses) in each area in 2025 (Table 3.15), in comparison to those in 2024. For example, in Morecambe Bay, the increase in dose, in 2025, to 0.023mSv (from 0.020mSv in 2024) was mostly due to higher gamma dose rates. All annual doses of the wider communities were well within the dose limit for members of the public of 1mSv.

The dose to a person, who typically consumes 15kg of fish per year from landings at Whitehaven is also given in Table 3.16. This dose was less than 0.005mSv in 2025. The consumption rate used represents an average for a typical consumer of seafood from the north-east Irish Sea.

Doses from sediments

The main radiation exposure pathway associated with sediments is due to external dose from gamma-emitting radionuclides adsorbed on intertidal sediments in areas frequented by the public. This dose can make a significant contribution to the total exposure of members of the public in coastal communities of the north-east Irish Sea but particularly in Cumbria and Lancashire. Gamma dose rates currently observed in intertidal areas are mainly due to radiocaesium and naturally occurring radionuclides. For some people, the following pathways may also contribute to doses from sediments: exposure due to beta-emitting radionuclides during handling of sediments or fishing gear; inhalation of re-suspended beach sediments; and inadvertent ingestion of beach sediments. These pathways are considered later. In the main, they give rise to only minor doses compared with those due to external gamma-emitters.

Gamma radiation dose rates over areas of the Cumbrian coast and further afield in 2025 are given in Table 3.9. The results of the assessment of external exposure pathways are included in Table 3.16. The highest whole-body exposures due to external radiation resulting from Sellafield discharges, past and present, was received by a local houseboat dweller at Barrow, Cumbria. In 2025, the dose was 0.065mSv, or less than 7% of the dose limit, and up from 0.060mSv in 2024 (see Section 6.2). Other people received lower external doses in 2025. The dose to a person who spends a long time over the marsh in the Ravenglass Estuary was 0.008mSv in 2025, and a decrease from that in 2024 (0.016mSv). This decrease in dose was due to lower occupancy over salt marsh (Appendix 4, Table A4.2).

The doses to people in 2025 were also estimated for several other activities. Assessments were undertaken for a typical resident using local beaches for recreational purposes at 300 hours per year, and for a typical tourist visiting the coast of Cumbria with a beach occupancy of 30 hours per year. The exposure to residents was assessed for 2 different environments (at several locations) and at a distance from the Sellafield influence. The 2 different environments are 1) residents that visit and use beaches, and 2) residents that visit local muddy areas or salt marsh. Typical occupancy rates (Clyne and others, 2008; Clyne and others, 2010) are assumed and appropriate gamma dose rates have been used from Table 3.9. The activities for the typical tourist include consumption of local seafood and occupancy on beaches. Concentrations of radioactivity in fish and shellfish have been used from Table 3.5 to Table 3.7, and appropriate gamma dose rates used from Table 3.9. The consumption and occupancy rates for activities of a typical resident and tourist are provided in Appendix 4 (Table A4.2).

In 2025, the doses to people from recreational use of beaches varied from less than 0.005 to 0.008mSv (Table 3.16), with the higher doses being closer to the Sellafield source. The doses for recreational use of salt marsh and muddy areas had a similar variation, from less than 0.005 to 0.009mSv. The values for these activities were similar to those in recent years. The annual dose to a typical tourist visiting the coast of Cumbria, including a contribution from external exposure, was estimated to be less than 0.005mSv.

Doses from handling fishing gear and sediment

Exposures can also arise from contact with beta-emitting radionuclides during handling of sediments, or fishing gear on which fine particulates have become trapped. Habits surveys keep under review the amounts of time spent by fishers handling their fishing gear, and by bait diggers and shellfish collectors handling sediment. For those most exposed, the rates for handling nets and pots and for handling sediments are provided in Appendix 4 (Table A4.2). In 2025, the skin doses to a bait digger and shellfish collector from handling sediment was 0.087mSv (Table 3.16). This was less than 0.5% of the appropriate annual dose limit of 50mSv specifically for skin. The skin dose to a fisherman from handling fishing gear (including a component due to naturally occurring radiation), based on 2019 monitoring data was 0.14mSv. Therefore, both handling of fishing gear and sediments continued to be minor pathways of radiation exposure.

Doses from atmospheric sea to land transfer

At Ravenglass, the representative person was infants (1-year-old) from consuming terrestrial foods that were potentially affected by radionuclides transported to land by sea spray. In 2025, the dose (including contributions from Chernobyl and fallout from nuclear weapons testing) was estimated to be 0.013mSv, which was less than 2% of the dose limit for members of the public, and generally similar to that in 2024 (0.014mSv). The largest contribution to the dose was, from ruthenium-106 in milk. As in previous years, sea-to-land transfer was not of radiological importance in the Ravenglass area.

Doses from seaweed and sea-washed pasture

Estimated annual doses for a high-rate consumer of laverbread (brown seaweed), and a high-rate consumer of vegetables (assuming these foods were obtained from the monitored plots near Sellafield and seaweeds were used as fertilisers and/or soil conditioners), are available in earlier RIFE reports (for example (Environment Agency and others, 2014)). Exposures of vegetable consumers using seaweed from further afield in Northern Ireland, Scotland and North Wales are expected to be much lower than near Sellafield.

Animals may also graze on seaweeds on beaches in coastal areas. However, there has been no evidence of this taking place significantly near Sellafield. A research study (relevant to the Scottish islands and coastal communities) conducted by UKHSA on behalf of the FSA and SEPA, investigated the potential transfer of radionuclides from seaweed to meat products and also to crops grown on land where seaweed had been applied as a soil conditioner (Brown and others, 2009). The study concluded that the highest levels of dose to people using seaweed, as a soil conditioner or an animal feed, were in the range of a few microsieverts (µSv) and most of the doses are at least a factor of 100 lower. The report is available from SEPA by emailing RSEnquiries@sepa.org.uk.

3.3.2. Gaseous discharges and monitoring

Permitted discharges to atmosphere are made from a wide range of facilities at the site including the fuel storage ponds, the reprocessing plants and waste treatment plants, as well as from Calder Hall Power Station. Discharges to atmosphere, during 2025 are summarised in Appendix 1 (Table A1.1). The permit limits gaseous discharges for gross alpha and beta activities, and 8 specified radionuclides. In addition to overall site limits, plant notification levels have been set on discharges from the main contributing plants on site.

3.3.2.1. Monitoring around the site related to gaseous discharges

Monitoring of terrestrial foods in the vicinity of Sellafield is conducted by the FSA to reflect the scale and risk of discharges from the site. This monitoring is the most extensive of that for the nuclear sites in the UK. A range of foodstuffs was sampled in 2025 including milk, fruit, vegetables, meat and offal, game, and environmental materials (grass and soil). Environmental samples were obtained from different locations around the site to allow for variations due to the influence of meteorological conditions on the dispersal of gaseous discharges. The analyses conducted included gamma-ray spectrometry and specific measurements for tritium, carbon-14, strontium-90, technetium-99, iodine-129, uranium and transuranic radionuclides.

The results of monitoring in 2025 are given in Table 3.4. The activity concentrations of most radionuclides around the site were generally low. Activity concentrations in milk, fruit, vegetables, meat and offal, game, and environmental materials (grass and soil) were generally similar to those in recent years. Activity concentrations of radionuclides in meat and offal (cattle and sheep) were low, with many reported as below the limit of detection with only very limited evidence of the effects of Sellafield’s gaseous discharges, detected in concentrations of carbon-14 in meat and offal samples. Concentrations of strontium-90, caesium-134, caesium-137 and transuranic radionuclides in wild wood pigeon were significantly higher than recorded over the last two decades (discussed in Section 3.3.3.12).

A range of foods (including fruit and vegetables) and terrestrial indicator materials was sampled in 2025, and the activity concentrations were generally similar to those found in previous years. In common with meat and offal samples, only limited evidence of the gaseous discharges from Sellafield was found in some of these foods. Strontium-90 was positively detected in a number of food samples (including milk) at low concentrations. As in 2024, the maximum iodine-129 and iodine-131 concentrations in milk were reported as below the limit of detection. Small enhancements (above the expected background) in concentrations of carbon-14 were found in some food samples (including milk), as in recent years. Concentrations of transuranic radionuclides, when detectable in these foods, were very low. Concentrations of radionuclides in milk (near Sellafield), and corresponding discharges of carbon-14, strontium-90 and caesium-137, for more than a decade are shown in Figure 3.16 to Figure 3.18, respectively. Over the whole period, concentrations of carbon-14 were relatively constant (with some variation between years and close to background), and caesium-137 concentrations (and strontium-90 to a lesser extent) were declining overall.

Figure 3.16. Concentrations of carbon-14 in milk, in Bq l^-1, near Sellafield and annual discharges of carbon-14, TBq y^-1 from in Sellafield, 2014 to 2025.

Figure 3.17. Concentrations of strontium-90 in milk, in Bq l^-1, near Sellafield and annual discharges of strontium-90, GBq y^-1 from in Sellafield, 2014 to 2025.

Figure 3.18. Concentrations of caesium-137 in milk, in Bq l^-1, near Sellafield and annual discharges of caesium-137, GBq y^-1 from in Sellafield, 2014 to 2025.

3.3.3 Liquid discharges and monitoring

Permitted liquid discharges derive from a variety of sources at the site including the fuel storage ponds, the reprocessing plants, from the retrieval and treatment of legacy wastes, the laundry and general site drainage. Wastes from these sources are treated and then discharged to the Irish Sea via the sea pipelines that terminate 2.1km beyond low water mark. A small quantity of low activity liquid wastes (mostly rainfall runoff) is also discharged from the factory sewer to the River Ehen Estuary and (since 2015) some liquid wastes are also discharged via the Calder Interceptor Sewer (Environment Agency and others, 2016). Discharges from the Sellafield pipelines during 2025 are summarised in Appendix 1 (Table A1.2). The current permit sets limits on gross alpha and beta, and 12 individual radionuclides. In addition to overall site limits, plant notification levels have been set on discharges from the main contributing plants on site (Segregated Effluent Treatment Plant, Site Ion Exchange Effluent Plant (SIXEP), Enhanced Actinide Removal Plant and THORP).

All discharges of liquid wastes from Sellafield were less than the permit limits in 2025. Liquid discharges of most radionuclides decreased, in 2025, compared to releases in 2024.

The downward trend of technetium-99 discharges from Sellafield is given in Figure 3.19 (2014 to 2025) and Figure 3.20 (1996 to 2025). Technetium-99 trends in seaweed around the UK are shown in Figure 3.21 to Figure 3.28. Technetium-99 discharges have substantially reduced from the peak of 192TBq in 1995. Further information relating to past discharges of technetium-99 is available in earlier RIFE reports (for example Environment Agency and others, 2019).

Figure 3.19. Technetium-99 in Sellafield seaweed (‘Fucus vesiculosus’), in Bq kg^-1 (fresh), and Sellafield discharges, in TBq y^-1.

Figure 3.20. Technetium-99 in UK seaweed (‘Fucus vesiculosus’), in Bq kg^-1 (fresh), and Sellafield liquid discharges between, in TBq y^-1, 1996 to 2025.

Figure 3.21.Technetium-99 in Dounreay seaweed (‘Fucus vesiculosus’), in Bq kg^-1 (fresh), 2014 to 2025

Figure 3.22.Technetium-99 in Hartlepool seaweed (‘Fucus vesiculosus’), in Bq kg^-1 (fresh), 2014 to 2025

Figure 3.23.Technetium-99 in Bradwell seaweed (‘Fucus vesiculosus’), in Bq kg^-1 (fresh), 2014 to 2025

Figure 3.24.Technetium-99 in Dungeness seaweed (‘Fucus vesiculosus’), in Bq kg^-1 (fresh), 2014 to 2025

Figure 3.25.Technetium-99 in Isles of Scilly seaweed (‘Fucus vesiculosus’), in Bq kg^-1 (fresh), 2014 to 2025

Figure 3.26.Technetium-99 in Fishguard seaweed (‘Fucus vesiculosus’), in Bq kg^-1 (fresh), 2014 to 2025

Figure 3.27.Technetium-99 in Ardglass seaweed (‘Fucus vesiculosus’), in Bq kg^-1 (fresh), 2014 to 2024

Figure 3.28.Technetium-99 in Port William seaweed (‘Fucus vesiculosus’), in Bq kg^-1 (fresh), 2014 to 2025

3.3.3.1. Monitoring of the marine environment

Regular monitoring of the marine environment near to Sellafield and further afield was conducted during 2025, by the Environment Agency and FSA (for England and Wales), NIEA (for Northern Ireland) and SEPA (for Scotland). In Scotland, SEPA and the FSS work closely together to maximise the value of every sample taken as it is fully funded by the Scottish Government. The monitoring locations for seafood, water, environmental materials and dose rates near the Sellafield site are shown in Figure 3.29 and Figure 3.30, the corresponding sample species, types and locations are listed in the corresponding site tables.

Figure 3.29. Monitoring locations in Cumbria, 2025 (not including farms).

Figure 3.30. Monitoring locations at Sellafield, 2025 (not including farms).

3.3.3.2. Monitoring of fish and shellfish

Concentrations of beta and gamma activity in fish from the Irish Sea and from further afield are given in Table 3.5. Data are listed by location of sampling or landing point, north to south in Cumbria, then in approximate order of increasing distance from Sellafield. Results are available for previous specific surveys in the ‘Sellafield Coastal Area’ (extending 15km to the north and to the south of Sellafield, from St Bees Head to Selker, and 11km offshore) and the smaller ‘Sellafield Offshore Area’ (consisting of a rectangle, 1.8km wide by 3.6km long, situated south of the pipelines) in earlier RIFE reports (for example, Environment Agency and others, 2014). Concentrations of specific naturally occurring radionuclides in fish and shellfish in the Sellafield area are given in Section 7.

The concentrations of most radionuclides have decreased over the previous decades in response to decreases in discharges (Environment Agency and others, 2011). Concentrations generally continue to reflect changes in discharges over time periods, characteristic of radionuclide mobility and organism uptake. More recent trends in concentrations of radionuclides, and corresponding discharges, in seafood near Sellafield (over the last decade) are shown in Figure 3.31 to Figure 3.36. There was variability from year to year, particularly for the more mobile radionuclides. Over the period 2014 to 2025, discharges and the concentrations of carbon-14 in fish and shellfish have declined (Figure 3.31). Discharges of cobalt-60 have decreased over the period 2014 to 2025 (Figure 3.32). However, concentrations in fish and shellfish have shown some variation year on year, albeit at low concentrations. Liquid discharges of technetium-99 and concentrations of technetium-99 in fish and shellfish in 2025 (Figure 3.33) were similar, in comparison to their respective values in recent years. Over a longer timescale, technetium-99 concentrations in fish and shellfish have shown a continued reduction, from the relatively elevated values in the previous decade (Environment Agency and others, 2011). For the transuranic elements (Figure 3.35 and Figure 3.36), the trend of reductions in concentrations is not evident, unlike in earlier decades(Environment Agency and others, 2011). Over the last decade, discharges and concentrations of americium-241 and plutonium-239+240 in fish and shellfish have continued to show some variations from year to year (Figure 3.35 and Figure 3.36). Overall, these concentrations in shellfish have decreased over the period. The mean concentrations of carbon-14, cobalt-60, technetium-99, caesium-137, plutonium-239+240 and americium-241 in shellfish, were generally similar in 2025, compared to those in 2024.

Figure 3.31. Carbon-14 concentrations in plaice, lobsters and winkles from near Sellafield, in Bq kg^-1 (fresh) and liquid discharge from Sellafield, in TBq y^-1, 2014 to 2025.

Figure 3.32. Cobalt-60 concentrations in plaice, lobsters and winkles from near Sellafield, in Bq kg^-1 (fresh) and liquid discharge from Sellafield, in TBq y^-1, 2014 to 2025.

Figure 3.33. Technetium-99 concentrations in plaice, lobsters and winkles from near Sellafield, in Bq kg^-1 (fresh) and liquid discharge from Sellafield, in TBq y^-1, 2014 to 2025.

Figure 3.34. Caesium-137 concentrations in plaice, lobsters and winkles from near Sellafield, in Bq kg^-1 (fresh) and liquid discharge from Sellafield, in TBq y^-1, 2014 to 2025.

Figure 3.35. Plutonium-239+240 concentrations in plaice, lobsters and winkles from near Sellafield, in Bq kg^-1 (fresh) and liquid discharge from Sellafield, in TBq y^-1, 2014 to 2025.

Figure 3.36. Americium-241 concentrations in plaice, lobsters and winkles from near Sellafield, in Bq kg^-1 (fresh) and liquid discharge from Sellafield, in TBq y^-1, 2014 to 2025.

Beta- and gamma-emitting radionuclides detected in fish included tritium, carbon-14, technetium-99 and caesium-137 (Table 3.5). Overall, concentrations of caesium-137 in fish species, across a wide range of sampling locations, were generally similar in 2025, compared to those in 2024. Over longer time, activity concentrations in fish and shellfish appear to be generally declining (with minor variations) at a slow rate (Figure 3.34). Activity concentrations in fish (and shellfish) generally reflected progressive dilution with increasing distance from Sellafield. However, the rate of decline of caesium-137 concentrations with distance was not as marked as was the case when significant reductions in discharges were achieved in earlier decades.

Other artificial beta- and gamma-emitting radionuclides detected in fish included carbon-14 and tritium (Table 3.5). With an expected carbon-14 concentration from natural sources of about 19Bq kg^-1 (see Appendix 6, Table A6.1), the data suggest a continued local enhancement of carbon-14 due to discharges from Sellafield. In 2025, carbon-14 is reported as the highest activity concentration in marine fish (plaice, 31Bq kg^-1) from Ravenglass. In 2025 most of both tritium and organically bound tritium (OBT) values, across all species and locations, were reported as below the limit of detection.

For shellfish, a wide range of radionuclides is detectable, owing to generally greater uptake of radioactivity by these organisms from sediments. Generally, molluscs tend to contain higher concentrations than crustaceans and both contain higher concentrations than fish. Concentrations of beta- and gamma-emitting radionuclides are shown in Table 3.6 (Table 3.7 for plutonium-241). There can be substantial variations between species; for example, lobsters tend to concentrate more technetium-99 than crabs (as shown in references, Knowles, Smith & Winpenny 1998; Swift & Nicholson 2001j). The highest concentrations in the marine environment from Sellafield discharges were carbon-14, tritium and technetium-99. Comparing 2024 and 2025 data across a wide range of sampling locations and shellfish species (where comparisons can be made), technetium-99 concentrations were similar (with minor variations) but reduced in comparison to those years prior to 2012 due to the progressive reductions in discharges of this radionuclide. Concentrations of other radionuclides (non-transuranic) in 2025 were also broadly similar (where comparisons can be made) to those in 2024.

Transuranic radionuclide data for fish and shellfish samples (chosen on the basis of potential radiological significance) in 2025 are given in Table 3.7. Transuranic elements are less mobile than other radionuclides in seawater and have a high affinity for sediments. This is reflected in higher concentrations of transuranic elements in shellfish compared with fish. Comparing 2025 and 2024 data across a wide range of sampling locations and shellfish species further afield from Sellafield, concentrations in shellfish were generally similar (where comparisons can be made). Those from the north-eastern Irish Sea were the highest transuranic concentrations found in foodstuffs in the UK. In 2025, the concentrations of plutonium and americium-241 in shellfish were generally lower (by small amounts) compared to those in 2024 at most of the north-eastern Irish Sea locations (for example, winkles from Parton). Americium-241 concentrations in mussels (near Sellafield) were also generally similar in 2025, compared to those in 2024. Overall, plutonium-239+240 and americium-241 concentrations in lobsters (near Sellafield) were generally similar (with minor variations) in 2025, compared to those in recent years. Variations of these observations in previous years were likely to have resulted from a combination of mechanisms including natural environmental variability and redistribution of sediments due to natural processes.

3.3.3.3. Monitoring of sediments

Radionuclides in Sellafield liquid discharges are taken up by sediments along the Cumbrian Coast, in particular in muddier (fine grained) areas such as estuaries. Some of these areas are used by the public. Concentrations of radionuclides are regularly monitored, both because of their relevance to exposure and to keep distributions of radioactivity under review. The results for 2025 are shown in Table 3.8. Radionuclides positively detected were cobalt-60, strontium-90, caesium-137, and transuranic elements. The highest concentrations found are close to the site and in fine particulate materials in estuaries and harbours, rather than the coarser grained sands on open beaches. In 2025, the concentrations of caesium-137 and plutonium-238, plutonium-239+240, plutonium-241 and americium-241 radionuclides were lower in the River Mite Estuary (an erosional area), compared to those in 2024. The concentrations of long-lived radionuclides, particularly caesium-137 and the transuranic elements, largely reflect past discharges from Sellafield, which were considerably higher than in recent years. Over the last 4 decades, discharges have fallen significantly as the site provided enhanced treatment to remove radionuclides prior to discharge. Overall, concentrations in sediments were generally similar in 2025, compared to those in 2024.

The trends over time (1996 to 2025) for activity concentrations in mud from Ravenglass and liquid discharges from Sellafield are shown in Figure 3.37 to Figure 3.40. The concentrations of most radionuclides have declined over the time period in response to decreases in discharges, with sustained reductions in discharges of caesium-137 and transuranic elements. Discharges of cobalt-60 have been variable in the earlier years but reduced over the last decade, as reflected in the sediment concentrations at Ravenglass, with some evidence of a time lag between discharge and sediment concentration (Figure 3.39). Over the last decade, caesium-137 and transuranic concentrations in sediments have remained relatively constant (Figure 3.37, Figure 3.38 and Figure 3.40). Since the mid-1990s, discharges of caesium-137, plutonium isotopes and americium-241 have remained low, but with some variability. There is a suggestion of small progressive increases in caesium-137 and transuranic elements activities in sediments (peaking in both 2006 and 2014). The likely explanation is that changes in these concentrations are due to remobilisation and subsequent accretion of fine-grained sediments containing higher activity concentrations. For americium-241, there is also a contribution due to radioactive in-growth from the parent plutonium-241 already present in the environment. The effect is less apparent in fish and shellfish (Figure 3.34 to Figure 3.36) and will continue to be monitored.

Figure 3.37. Caesium-137 concentration in mud at Ravenglass, in Bq kg^-1 (dry), liquid discharge from Sellafield, in TBq y^-1, 1996 to 2025.

Figure 3.38. Plutonium-alpha concentration in mud at Ravenglass, in Bq kg^-1 (dry), liquid discharge from Sellafield, in TBq y^-1, 1996 to 2025.

Figure 3.39. Cobalt-60 concentration in mud at Ravenglass, in Bq kg^-1 (dry), liquid discharge from Sellafield, in TBq y^-1, 1996 to 2025.

Figure 3.40. Americium-241 concentration in mud at Ravenglass, in Bq kg^-1 (dry), liquid discharge from Sellafield, in TBq y^-1, 1996 to 2025.

Concentrations of caesium-137 and americium-241 in sediments from coastal locations of the north-east Irish Sea, including locations on the Dumfries and Galloway coast, Cumbrian coastline, Flookburgh, River Ribble estuary and North Wales coast, are also shown in Figure 3.41 to Figure 3.48 . Concentrations of both radionuclides diminish with distance from Sellafield. Overall, concentrations in 2025 at a given location were generally similar to those in recent years, and any fluctuations were most likely due to the normal variability expected in the environment.

Figure 3.41. Concentrations of americium-241 and caesium-137 in coastal sediments, in Bq kg^-1 (dry), at Innerwell between 1999 to 2025

Figure 3.42. Concentrations of americium-241 and caesium-137 in coastal sediments, in Bq kg^-1 (dry), at Carsluith between 1999 to 2025

Figure 3.43. Concentrations of americium-241 and caesium-137 in coastal sediments, in Bq kg^-1 (dry), at Newton between 1999 to 2025

Figure 3.44. Concentrations of americium-241 and caesium-137 in coastal sediments, in Bq kg^-1 (dry), at Carleton Marsh between 1999 to 2025

Figure 3.45. Concentrations of americium-241 and caesium-137 in coastal sediments, in Bq kg^-1 (dry), at Newbiggins/Eskmeals between 1999 to 2025

Figure 3.46. Concentrations of americium-241 and caesium-137 in coastal sediments, in Bq kg^-1 (dry), at Flookburgh between 1999 to 2025

Figure 3.47. Concentrations of americium-241 and caesium-137 in coastal sediments, in Bq kg^-1 (dry), at the River Ribble outfall between 1999 to 2025

Figure 3.48. Concentrations of americium-241 and caesium-137 in coastal sediments, in Bq kg^-1 (dry), at Caerhun between 1999 to 2025

3.3.3.4. Monitoring of dose rates

Dose rates are regularly monitored at many locations, both in the Sellafield vicinity and further afield, using environmental radiation dosimeters. Table 3.9 provides the locations monitored by the environment agencies and the gamma dose rates in air at 1 metre above ground. Where comparisons can be made from similar ground types and locations, dose rates over intertidal areas throughout the Irish Sea in 2025 were generally similar to those in recent years (with small variations compared to those in 2024). Any variations between years are likely to have been due to normal variability expected in the environment. As in previous years, gamma dose rates were measured on the banks of the River Calder, which flows through the Sellafield site. In 2025, gamma dose rates did not show a significant excess above natural background downstream of the site. Although these dose rates have been locally enhanced in previous years on the banks of the River Calder, occupancy by the public (mainly anglers) is low in this area, this is unlikely to be more than a few tens of hours per year. On this basis, the resulting doses (in previous years) were also much less than those at other intertidal areas as discussed earlier in this section.

Gamma dose rates above mud and salt marshes, from a range of coastal locations in the vicinity of Sellafield, are shown in Figure 3.49 to Figure 3.56 (2014 to 2025). Gamma dose rates at sandy locations are generally lower than those above mud or salt marshes. The general decrease in dose rates with increasing distance from Sellafield, which was apparent under conditions of higher discharges several decades ago, is no longer so prominent in recent years. Spatial variability of dose rates is expected, depending on ground type, with generally higher dose rates recorded over areas with finely grained sediments. For each location, there has been variation over time. Close to Sellafield (at Carleton Marsh and Newbiggin), there is some evidence to suggest that dose rates were slowly declining over time. Locations that are further afield from Sellafield show dose rate values that only marginally exceed average UK natural background rates.

Figure 3.49. Gamma dose rates, in microGy h^-1, above fine coastal sediments (mud and salt marshes) at Innerwell between 2014 to 2025.

Figure 3.50. Gamma dose rates, in microGy h^-1, above fine coastal sediments (mud and salt marshes) at Carsluith between 2014 to 2025.

Figure 3.51. Gamma dose rates, in microGy h^-1, above fine coastal sediments (mud and salt marshes) at Newton Arlosh between 2014 to 2025.

Figure 3.52. Gamma dose rates, in microGy h^-1, above fine coastal sediments (mud and salt marshes) at Carleton Marsh between 2014 to 2025.

Figure 3.53. Gamma dose rates, in microGy h^-1, above fine coastal sediments (mud and salt marshes) at Newbiggin/Eskmeals between 2014 to 2025.

Figure 3.54. Gamma dose rates, in microGy h^-1, above fine coastal sediments (mud and salt marshes) at Flookburgh between 2014 to 2025.

Figure 3.55. Gamma dose rates, in microGy h^-1, above fine coastal sediments (mud and salt marshes) at the River Ribble outfall between 2014 to 2025.

Figure 3.56. Gamma dose rates, in microGy h^-1, above fine coastal sediments (mud and salt marshes) at Caerhun between 2014 to 2025.

Over the last 4 decades, concentrations of radioactivity in the environment around Sellafield have declined as a result of reduced discharges. In more recent years, the values in the Esk Estuary have shown a less clear trend, with concentrations of some radionuclides fluctuating from year to year (for example, see Figure 3.38). This effect could be due to the dynamic nature of the sediment in the estuary, which is eroded and transported by tide and freshwater, periodically exposing older sediment (from depth) containing radioactivity from historical discharges. Due to annual variations and local concerns, the Environment Agency initiated a more detailed study of dose rates in the Esk Estuary in 2007. Further information providing more background information, and describing the objectives and results of this study, is available in earlier RIFE reports (for example Environment Agency and others, 2015).

3.3.3.5. Monitoring of fishing gear

During immersion in seawater, fishing gear may trap particles of sediment on which radioactivity is adsorbed. Fishers handling this gear may be exposed to external radiation, mainly to skin from beta particles. Up to 2019, fishing gear was regularly monitored using surface contamination monitors. As in recent years, no monitoring of fishing gear was performed in 2025. Results up to 2019 are included in previous RIFE reports (for example, Environment Agency and others, 2020).

3.3.3.6. Contact dose-rate monitoring of intertidal areas

Results from measurements of beta dose rates on shoreline sediments (using contamination monitors), to allow estimation of exposure of people who handle sediments regularly, are given in Table 3.10. Overall, positively detected dose rates in 2025 were generally similar to those in 2024 (where comparisons can be made from similar ground types and locations). Beta dose rates measured over sand in 2025 were similar at St Bees compared to those in 2024. However, reported beta dose rates are low, with no radiological significance.

In 2008, the Environment Agency published a formal programme of work for the assessment of contamination by radioactive particles and objects^{[footnote 8]} on and around the west Cumbrian coastline. The assessment was focused on public protection from high activity discrete radioactive particles that have been released to the environment from activities at the Sellafield site (Environment Agency 2008).

Beach survey work using vehicle mounted detectors, by the Sellafield site operator’s contractors, began in 2006. The current detection system in use is the Groundhog™ Synergy2 system, which was introduced in mid-2014 and was designed, and introduced, to further improve detection of americium-241 and strontium-90/yttrium-90. This replaced the Groundhog^TM Synergy system, which was used from mid-2009 to mid-2014, which had a specific capability in relation to the detection of medium and high energy gamma-emitting radionuclides. The Groundhog^TM Synergy system also provided improved detection capability for low energy gamma emissions (in comparison to the original system introduced in 2006), increasing the ability to detect particles containing americium-241.

Further beach monitoring for the 2025 calendar year was completed in line with the Environment Agency’s specification (Sellafield Limited 2026). During 2025, a total area of 117 hectares of the beaches along the Cumbrian coast were surveyed against a programme target of 105 hectares. A total of 49 particles and 3 larger objects were detected, recovered and analysed. The number of radioactive finds identified was 52 in 2025, of which approximately 94% were classified as particles (less than 2mm in size) and the remainder as larger objects. The number of finds were typical of those in recent years (for a summary of finds, see Sellafield beach monitoring. All of the finds were recovered from beaches between Drigg point and St Bees. All have been removed from the beaches. In 2025, none of the finds detected exceeded the characterisation triggers set within the Environment Agency’s intervention trigger levels: Sellafield radioactive objects intervention plan.

Monitoring along the Cumbrian coast will continue in 2026, with the current proposal being a further 105 hectares to be surveyed.

In 2012, UKHSA reported their review of the results and position on risk following the introduction of the improved monitoring (Groundhog™ Synergy system). The report concluded that the increase in particle finds following the introduction of this system was a result of its improved capability and also that advice previously given by UKHSA to the Environment Agency following a detailed assessment of risks in 2010 remained valid (Brown & Etherington 2011; Etherington and others, 2012). The report restated the conclusion that, based on the currently available information, the overall health risks to beach users are very low and significantly lower than other risks people accept when using the beaches. As such, UKHSA advice remained that no special precautionary actions were required to limit access to or use of the beaches. A report by UKHSA describes the assessed health risks from the consumption of seafood (including those to commercial fishers) from radioactive particles in the vicinity of the Sellafield Site (Oatway & Brown 2015). Based on currently available information, it is concluded that the overall health risks to both seafood consumers and commercial fishers are very low. More recently, UKHSA were requested by the Environment Agency to update their recommendations, if supported by available evidence. This is to account for the information from the beach monitoring programme and from the further analysis of finds that have been collected since 2012. A summary report of assessing the risk to people’s health from radioactive objects on beaches around the Sellafield site was published by UKHSA in February 2020, concluding that the risk is very low (Oatway, Cabianca & Jones 2020). Longer term trends on the number of finds and their characteristics have been published (Newsome & Hill 2025)

In relation to food safety (and following a previous assessment of the particles frequency and the activity concentrations), FSA’s guidance to the Environment Agency supported UKHSA’s advice. The Environment Agency will continue to work with relevant authorities to keep the situation under review.

In 2007, SEPA published a strategy document for the assessment of the potential impact of Sellafield radioactive particles on members of the public in south-west Scotland (Scottish Environment Protection Agency 2007) and the beach monitoring programme was temporarily extended to include 2 locations on the north Solway coastline (Kirkcudbright Bay and Southerness). This was based on some limited modelling work on the movement of particles undertaken for the Environment Agency following a request by SEPA. No particles were detected at these locations. SEPA is maintaining a watching brief on the situation in as much as it may affect Scotland.

Further detail on enhanced beach monitoring data compiled so far can be obtained on the UK government website: Sellafield radioactive objects intervention plan - monitoring beaches near sellafield.

3.3.3.7. Monitoring of seaweed

Seaweeds are useful indicator materials, in addition to their occasional use in foods and as fertilisers. Seaweeds have the capability to readily accumulate radionuclides and thereby assist in the detection of these radionuclides in the environment. Table 3.11 gives the results of measurements in 2025 of seaweeds from shorelines of the Cumbrian coast and further afield. When comparing between 2024 and 2025 data across a wide range of sampling locations, radionuclide concentrations were generally similar (where comparisons can be made) in seaweeds.

Fucus species of seaweeds are particularly useful indicators of most fission product radionuclides. In particular, samples of ‘Fucus vesiculosus’ are collected both in the Sellafield vicinity and further afield to show the extent of Sellafield contamination in north European waters. The effects of technetium-99 discharges from Sellafield on concentrations in seaweed are shown in Figure 3.19 (2014 to 2025) and Figure 3.20 (1996 to 2025). In the north-east Irish Sea, technetium-99 concentrations have been reasonably constant over the present decade, consistent with the relatively low discharges; the highest concentrations which were found near Sellafield were much less than those in the mid-1990s and the decade thereafter (in response to the progressive reduction in discharges). In general, there was also a large reduction in concentrations of technetium-99 in ‘Fucus vesiculosus’ with distance from Sellafield, as the effect of the discharges becomes diluted in moving further afield.

Technetium-99 concentrations in seaweed (Table 3.11) collected from sites in Cumbria were generally lower by small amounts in 2025, compared to those in 2024. Over the last 5 years, small variations have been found, year on year, but technetium-99 concentrations in seaweed in 2025 were still low (Figure 3.19). At one specific location (Auchencairn, Scotland), known to have had fluctuating concentrations in previous years, technetium-99 concentrations in seaweed (Fucus) were higher in 2025 than those in 2024. The reasons behind these variations have been described in previous RIFE reports (for example Environment Agency and others, 2019).

3.3.3.8. Monitoring of tide-washed pasture

The potential transfer of technetium-99 to milk, meat and offal from animals grazing tide-washed pasture was considered using a modelling approach in the report for 1997 (Ministry of Agricultrure Fisheries and Food & Scottish Environment Protection Agency 1998). The maximum potential dose was calculated to be 0.009mSv per year, at that time. Follow-up sampling of tide-washed pastures at Newton Arlosh (Cumbria) and Hutton Marsh (Lancashire) in 2006 suggested that this dose estimate remains valid (Environment Agency and others, 2007).

3.3.3.9. Monitoring of sea to land transfer

Terrestrial foodstuffs are monitored near Ravenglass to check on the extent of transfer of radionuclides from sea to land in this area. In 2025, samples of milk and livestock were collected and analysed, for radionuclides which were released in liquid effluent discharges from Sellafield. Results from surveys for activity concentrations in crops, fruit and environmental indicators are available in earlier RIFE reports (for example, Environment Agency and others, 2014).

The results of measurements in 2025 are given in Table 3.12. Generally, the activity concentrations, where positively detected, show lower concentrations than were found in the immediate vicinity of Sellafield (Table 3.4). As in previous years, the evidence for sea to land transfer was very limited in 2025. Technetium-99 concentrations are reported as below (or close) to the limit of detection. Small concentrations of artificial nuclides were detected in some samples, but the concentrations were very low. As in recent years, where detectable, observed isotopic ratios of plutonium-238 to plutonium-239+240 concentrations were somewhat higher than 0.025, a ratio which might be expected if the source was entirely due to fallout from nuclear weapons testing. This may suggest a Sellafield influence.

3.3.3.10. Monitoring of fishmeal

A theoretical study has established that any indirect onward transmission of both naturally occurring and artificial radioactivity into the human diet from the fishmeal pathway (that is fed to farmed fish, poultry, pigs, cows and sheep) is unlikely to be of radiological significance (Smith & Jeffs 1999). A detailed survey was undertaken to confirm these findings (Food Standards Agency 2003). Samples, obtained from 14 fish farms in Scotland and 3 in Northern Ireland, contained very low radionuclide concentrations, most being less than the limits of detection, and the few positively detected values were all less than 1Bq kg^-1. Annually reported RIFE results for activity concentrations in farmed salmon from the west of Scotland confirm the findings of the FSA study (for example, Tables 2.5 and 2.7 (Environment Agency and others, 2014)).

3.3.3.11. Monitoring of waters

Evidence of the effects of liquid discharges from Sellafield on concentrations of radionuclides in seawater is determined by sampling from research vessels and the shore. The results of the seawater programme are given in Section 8.

Sampling of freshwater from rivers and lakes in west Cumbria is conducted as part of the regular environmental monitoring programme around Sellafield. However, other environmental materials are likely to be more indicative of direct site-related effects. Some of the sources monitored provide public drinking water. The results for 2025 are included in Table 3.13. Tritium, gross alpha and gross beta concentrations in public supplies were below the investigation levels for drinking water in the Water Supply (Water Quality) (Amendment) 2018 Regulations (retained from the European Directive 2013/51).

Small amounts of radioactivity are discharged from Sellafield under permit via the factory sewer outfall to the River Ehen Estuary, immediately prior to the confluence with the River Calder. In 2025, there was no evidence of tritium downstream or upstream of the outfall (Table 3.13). These are not drinkable waters, and any low concentrations observed previously are of no radiological significance. Table 3.13 also includes the results of monitoring from Ehen Spit beach (Figure 3.29) near Sellafield where water issues from the ground at low tide. This release is not due to permitted discharges of liquid wastes but to ground water migration from the Sellafield site. The water contains high levels of salt so it will not be used as a drinking water source and therefore the only consumption would be inadvertent (incidental). Enhanced gross beta and tritium concentrations were observed in 2025 with concentrations similar to those in recent years. The annual dose from inadvertent consumption of water from Ehen Spit has been shown to be insignificant (Environment Agency 2002).

3.3.3.12. Monitoring of unusual pathways

In 2025, concentrations of caesium-137 were significantly higher than recorded over the last two decades. This was due to elevated levels of caesium-137 found in the muscle of wild wood pigeon near Sellafield, with the concentration being reported as 1600Bq kg^-1. Results of the analysis of this wild wood pigeon sample collected in 2025 are included in Table 3.4.

In 1998, high caesium-137 concentrations (up to 110,000Bq kg^-1) were found in feral pigeons sampled in Seascale by the Ministry for Agriculture, Fisheries & Food (Ministry of Agriculture Fisheries and Food & Scottish Environment Protection Agency 1999). MAFF issued precautionary advice not to eat feral pigeons in the vicinity of Sellafield and this advice has not subsequently been rescinded. Further background information, describing the consequences of this monitoring, and remedial measures taken by the site operator, is available in earlier RIFE reports (for example Environment Agency and others, 2015).

Therefore, in 2025, while caesium-137 in pigeons was higher than in previous years, the levels remain orders of magnitude lower than in 1998. From a food safety perspective, there is minimal concern, due to the current advice in place not to eat wild wood pigeons and the supporting evidence from recent Habits surveys (Moore and others, 2024a) which indicate that wood pigeons do not represent a significant dietary pathway for local populations, meaning the associated risk of radiological exposure is expected to be low. As there is no suggestion of any consumption of feral pigeons, no further controls have been needed to be proposed. However, as a precautionary measure in the unlikely event that feral pigeons are consumed, the wild wood pigeon data has been included in the terrestrial dose assessment in accordance with the National Dose Assessment Working Group (NDAWG) guidance and the “other foodstuffs” selection rules outlined in Section 2.8. The assessment demonstrated that, even when these results are taken into account, the resulting dose to members of the public remains within acceptable legal limits (see Table 1.4 and Table 3.16).

The cause of the elevated levels is under consideration and results of samples collected in 2026, will be reported in RIFE 32.

Following discovery of elevated concentrations in feral pigeons in 1998, the Environment Agency began to sample and analyse sediments from road drains (gully pots) in Seascale and Whitehaven in 1999. Gully pots in road drains collect sediments washed off road surfaces and provide good indicators of radiological contamination of urban environments. The results of analyses in 2025 are shown in Table 3.14. Overall, activity concentrations are generally similar to those in recent years, although caesium-137 concentrations decreased, by small amounts, in 2025. Further information of the previously elevated concentrations (of strontium-90, caesium-137, americium-241 and plutonium radionuclides) in road drain sediments is given in earlier RIFE reports (for example Environment Agency and others, 2019).

4. Nuclear power stations

Highlights

• For nuclear power stations assessed in 2025 the ‘total dose’ for the representative person was 2% (or less) of the annual dose limit

England

Berkeley, Gloucestershire and Oldbury, South Gloucestershire

• ‘total dose’ for the representative person was less than 0.005mSv in 2025 and was unchanged from 2024

Bradwell, Essex

• ‘total dose’ for the representative person was less than 0.005mSv in 2025 and was unchanged from 2024

Dungeness, Kent

• ‘total dose’ for the representative person was 0.010mSv in 2025 and was unchanged from 2024

Hartlepool, County Durham

• ‘total dose’ for the representative person was 0.007mSv in 2025 and was unchanged from 2024

Heysham, Lancashire

• ‘total dose’ for the representative person was 0.017mSv and increased slightly in 2025 compared to 2024

Hinkley Point, Somerset

• ‘total dose’ for the representative person was 0.011mSv and decreased in 2025 compared to 2024

Sizewell, Suffolk

• ‘total dose’ for the representative person was 0.010mSv and decreased in 2025 compared to 2024

Scotland

Chapelcross, Dumfries and Galloway

• ‘total dose’ for the representative person was 0.007mSv in 2025 and was unchanged from 2024

Hunterston, North Ayrshire

• ‘total dose’ for the representative person was 0.007mSv and increased slightly in 2025 compared to 2024

Torness, East Lothian

• ‘total dose’ for the representative person was 0.010mSv and decreased slightly in 2025 compared to 2024

Wales

Trawsfynydd, Gwynedd

• ‘total dose’ for the representative person was 0.015mSv and increased in 2025 compared to 2024

Wylfa, Isle of Anglesey

• ‘total dose’ for the representative person was 0.006mSv in 2025 and decreased compared to 2024

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This section considers the results of environment and food monitoring, under the responsibility of the Environment Agency, FSA, FSS, NRW and SEPA, undertaken near nuclear power stations (both operating stations and stations being decommissioned). There is a total of 18 nuclear power stations (which may contain more than 1 reactor and more than 1 reactor type) at 13 locations in the UK as listed in the highlights section above.

Ten of the 18 nuclear power stations are older, first-generation nuclear power stations (Magnox reactors), owned by the NDA. The NDA was set up under the Energy Act 2004 and is a non-departmental public body (sponsored and funded by DESNZ). Its remit is to secure the decommissioning and clean-up of the UK’s civil nuclear power sites. All first-generation nuclear power stations are now in the process of decommissioning, including Calder Hall which is operated by Sellafield Limited (see Section 3). The remaining first-generation nuclear power stations are operated by NRS Limited (formerly Magnox Limited).

All first-generation nuclear reactors have now been completely defuelled. In March 2026, the NDA published its annual business plan (April 2026 to March 2029) and a new strategy. The plan summarises the programme of work at each of the sites (Nuclear Decommissioning Authority 2026).

Six AGR power stations and one Pressurised Water Reactor power station are owned and operated by EDF Energy Nuclear Generation Limited. These are Dungeness B, Hartlepool, Heysham 1 and 2, Hinkley Point B, Sizewell B Power Stations in England, and Torness Power Station in Scotland. In 2021, EDF decided to move Dungeness B into defuelling phase following an extended outage in the previous years. In 2021, the UK government and EDF signed an agreement to transfer control of the AGR power stations to the NDA after cessation of generation and defuelling of the reactors. Hinkley Point B stopped generating electricity in 2022, became officially fuel free in January 2026. Ownership is now expected to be transferred to NRS in late 2026. Hunterston B stopped generating electricity in 2022 and defuelling was completed in 2025. In April 2026, Hunterston B nuclear power station ownership was transferred to Nuclear Restoration Services (NRS).

Gaseous and liquid discharges from each of the power stations are regulated by the Environment Agency and NRW in England and Wales, respectively and by SEPA in Scotland. In 2025, gaseous and liquid discharges were below regulated limits for each of the power stations (see Appendix 1, Table A1.1 and Table A1.2). Solid waste transfers in 2025 from nuclear establishments in Scotland (Chapelcross, Hunterston A, Hunterston B and Torness) are also given in Appendix 1 (Table A1.4). Independent monitoring of food and the environment around each of the power stations is conducted by the FSA and the Environment Agency in England and Wales, and by SEPA in Scotland. The Environment Agency undertakes the monitoring in Wales on behalf of NRW and the Welsh Government.

Data tables and the detailed results of the dose assessments, in Open Document Spreadsheet (ODS) format, are downloadable from the main RIFE page.

4.1. England

4.1.1 Berkeley, Gloucestershire and Oldbury, South Gloucestershire

Berkeley and Oldbury are both first-generation nuclear power stations. Berkeley Power Station is situated on the eastern bank of the River Severn and was powered by 2 Magnox reactors. Berkeley was the first commercial power station in the UK to enter decommissioning. Electricity generation started in 1962 and ceased in 1989. Defuelling was completed in 1992. Decommissioning is still in progress and small amounts of radioactive wastes are still generated by these operations. In 2021, a modular encapsulation plant went into service to treat intermediate level waste (ILW) and to make it suitable for longer term storage and eventual disposal.

Oldbury Power Station is located on the south bank of the River Severn close to the village of Oldbury-on-Severn and has 2 Magnox reactors. Electricity generation started in 1967 and ceased in 2012. Defuelling was completed in 2016, and the site is now prioritising the retrieval, treatment, and storage of intermediate level waste.

Berkeley and Oldbury sites are considered together for the purposes of environmental monitoring because the discharge effects from both sites impact on the same area. The most recent habits survey was undertaken in 2014 (Clyne, Garrod & Papworth 2015). A new habits survey was conducted during the summer of 2026; the results are which are expected to be published in early 2027.

4.1.1.1. Doses to the public

In 2025, the ‘total dose’ from all pathways and sources of radiation was less than 0.005mSv (Table 4.1), or less than 0.5% of the dose limit to members of the public. This is unchanged from recent years. The representative person in 2025 was an infant consuming milk and a change from 2024 (adult spending time over sediments). The trend in the ‘total dose’ over the period 2014 to 2025 is given in Figure 4.1. Any longer-term variations in ‘total dose’ over time are attributable to changes in the contribution from direct radiation.

Figure 4.1. ‘Total dose’, in mSv y^-1, at Berkeley and Oldbury nuclear power stations, 2014 to 2025. (Small doses less than or equal to 0.005mSv are recorded as being 0.005mSv).

Year	Dose, mSv y-1
10% of the Dose limit	0.10
2014	0.005
2015	0.005
2016	0.006
2017	0.005
2018	0.005
2019	0.005
2020	0.005
2021	0.013
2022	0.005
2023	0.005
2024	0.005
2025	0.005

As in recent years, the source-specific assessments for a high-rate consumer of fish and shellfish, in the vicinity of the Berkeley and Oldbury sites, gave exposures that were less than 0.005mSv in 2025 (Table 4.1). The dose to a consumer of fish and shellfish includes external gamma radiation and a component due to the tritium historically discharged from the Maynard Centre, the former GE Healthcare Limited plant at Cardiff^{[footnote 9]}. As in recent years, the estimated dose for a high-rate consumer (infant) of locally grown foods gave an exposure of less than 0.005mSv in 2025.

The estimated dose for houseboat dwellers was 0.028mSv in 2025. This is similar to that reported in 2024 (0.027mSv). The estimate is determined as a cautious value (and therefore not included in the ‘total dose’ assessment), because gamma dose rate measurements used were not necessarily representative of the categories of ground type and houseboat location (as identified in the habits survey (Clyne and others, 2015)).

4.1.1.2. Gaseous discharges and terrestrial monitoring

The Berkeley and Oldbury sites discharge gaseous radioactive wastes via separate stacks to the atmosphere. The gaseous discharge of carbon-14 from the Berkeley site decreased in 2025, compared to 2024. The focus of the terrestrial sampling was for the analyses of tritium, carbon-14 and sulphur-35 in milk and crops. Local freshwater samples were also analysed. Data for 2025 are given in Table 4.2(a). Unlike in 2024, sulphur-35 was not positively detected in barley in 2025. Carbon-14 concentrations in milk were above the default value used to represent background (see Appendix 5) and were slightly higher than those observed in 2024. Tritium, gross alpha and gross beta concentrations in surface water were below the investigation levels for drinking water in the Water Supply (Water Quality) (Amendment) 2018 Regulations (retained from the European Directive 2013/51).

4.1.1.3. Liquid waste discharges and aquatic monitoring

Liquid radioactive wastes are discharged to the Severn Estuary.

Analyses of seafood and marine indicator materials as well as measurements of external radiation were conducted over muddy intertidal areas. Data for 2025 are given in Table 4.2(a) and Table 4.2(b). Most of the artificial radioactivity detected was due to caesium-137, representing the combined effect of discharges from the sites, other nuclear establishments discharging into the Bristol Channel, fallout from nuclear weapons testing, and possibly a small Sellafield-derived component. In 2025, caesium-137 concentrations in sediment were similar to those observed in 2024 (Figure 4.2). Very small concentrations of other radionuclides were detected but taken together, were of low radiological significance. Gamma dose rates were generally similar to those observed in recent years.

Figure 4.2. Caesium-137 concentration, in Bq kg^-1 (dry), in marine sediments near Berkeley and Oldbury nuclear power stations between 2014 and 2025.

Year	137Cs concentration Bq Kg-1 (dry)
2014	19
2015	22
2016	18
2017	16
2018	13
2019	16
2020	13
2021	12
2022	12
2023	10
2024	23
2024	25

4.1.2. Bradwell, Essex

The Bradwell site is located on the south side of the Blackwater Estuary. This Magnox power station ceased electricity production in 2002 after 40 years of operation, and defuelling was completed in 2006. In 2018, Bradwell became the UK’s first Magnox site to reach the interim end-state of passive Care and Maintenance, following an accelerated decommissioning programme.

Following the cessation of intermediate level waste processing in 2018, environmental monitoring was reverted to baseline monitoring programme.

The most recent habits survey was undertaken in 2015 (Clyne, Garrod & Ly 2016).

4.1.2.1. Doses to the public

The ‘total dose’ from all pathways and sources of radiation was less than 0.005mSv in 2025 (Table 4.1), or 0.5% of the dose limit for members of the public and unchanged from 2024. The representative person in 2025 was an adult living on a houseboat and was unchanged from recent years. The trend in ‘total dose’ over the period 2014 to 2025 is given in Figure 4.3. Any significant variations in ‘total dose’ over time were attributed to changes in the estimate of direct radiation.

Figure 4.3. ‘Total dose’, in mSv y^-1, at Bradwell nuclear power station, 2014 to 2025. (Small doses less than or equal to 0.005mSv are recorded as being 0.005mSv).

Year	Dose, mSv y-1
10% of the Dose limit	0.10
2014	0.005
2015	0.017
2016	0.036
2017	0.011
2018	0.011
2019	0.005
2020	0.005
2021	0.006
2022	0.005
2023	0.005
2024	0.005
2025	0.005

As in recent years, the doses to a high-rate consumer of fish and shellfish and a high-rate consumer of locally grown foods from source-specific assessment were less than 0.005mSv in 2025.

4.1.2.2. Gaseous discharges and terrestrial monitoring

The power station is permitted to discharge gaseous wastes to the local environment via stacks to the atmosphere. Terrestrial sampling is similar to that for other power stations including analyses of milk and crop samples. Samples of freshwater are also taken from a coastal ditch. Data for 2025 are given in Table 4.3(a). Activity concentrations were low in terrestrial samples. As in recent years, carbon-14 was detected in locally produced milk at concentrations close to the expected background concentration. Unlike in 2024, strontium-90 was not positively detected in any coastal ditch freshwater samples in 2025. As in past years, the gross beta activities in water samples collected from the coastal ditch in 2025 were above the investigation levels for drinking water in the Water Supply (Water Quality) (Amendment) 2018 Regulations (retained from the European Directive 2013/51). However, the water in the ditches is not known to be used as a source of drinking water.

4.1.2.3. Liquid waste discharges and aquatic monitoring

Liquid wastes are discharged into the River Blackwater estuary. The main source of this effluent is rainwater runoff which is discharged to the estuary via the main drains pit at Bradwell site. The main drains pit is sampled at quarterly intervals. The site is also permitted to discharge non-radioactive effluent from the turbine hall voids to the main drains pit, and from there to the estuary. However, no effluent from this source was discharged in 2025. Effluent was last discharged to the estuary via Bradwell site’s active effluent system in 2017. This route has since been decommissioned and was removed from the environmental permit in 2019.

Aquatic sampling was directed at the consumption of locally caught fish and shellfish and external exposure over intertidal sediments. Seaweeds were also analysed as an environmental indicator material. Data for 2025 are given in Table 4.3(a) and Table 4.3(b). Low concentrations of artificial radionuclides were detected in marine samples as a result of discharges from the station, discharges from Sellafield and fallout from nuclear weapons testing. Due to the low concentrations detected, it is difficult to attribute these results to a particular source without any complementary forensic investigations. There has been an overall decline in caesium-137 concentrations in sediments over the last decade (Figure 4.4). The caesium-137 concentrations observed in sediment samples collected in 2025 were slightly higher than those reported in 2024. Gamma dose rates on beaches were difficult to distinguish from natural background and were generally similar to those observed in recent years.

Figure 4.4. Caesium-137 concentration, in Bq kg^-1 (dry), in marine sediments near Bradwell nuclear power station between 2014 and 2025.

Year	137Cs concentration Bq Kg-1 (dry)
2014	6.1
2015	6.2
2016	7.0
2017	6.7
2018	4.0
2019	3.9
2020	4.0
2021	3.2
2022	3.4
2023	3.2
2024	2.7
2025	3.5

4.1.3. Dungeness, Kent

The Dungeness power stations are located on the south Kent coast, between Folkestone and Rye. There are 2 separate A and B nuclear power stations on neighbouring sites: Dungeness A was powered by 2 Magnox reactors and Dungeness B has twin AGRs. Discharges are made via separate and adjacent outfalls and stacks, but for the purposes of environmental monitoring these are considered together. Dungeness A ceased generating electricity in 2006. Defuelling of both Magnox reactors was completed in 2012, and the site is currently undergoing decommissioning. In 2021, Dungeness B nuclear power station was moved into the defuelling phase following over 2 years of outage. A consultation led by EDF on proposals for the decommissioning of Dungeness B nuclear power station was run between March and April 2026. The most recent habits survey was conducted in 2019 (Greenhill and others, 2020).

4.1.3.1. Doses to the public

In 2025, the ‘total dose’ from all pathways and sources of radiation was 0.010mSv (Table 4.1), which was 1% of the dose limit to members of the public and was unchanged from 2024. As in 2024, the representative person was an adult spending extensive time over intertidal substrates in 2025. The trend in ‘total dose’ over the period 2014 to 2025 is given in Figure 4.5. The annual ‘total dose’ ranged between less than 0.005 and 0.037mSv over this period and were dominated by direct radiation. Over a longer time-series, this dose has declined more significantly from the peak value of 0.63mSv, following the shutdown of the Magnox reactors in 2006 (Environment Agency and others, 2018).

Figure 4.5. ‘Total dose’, in mSv y^-1, at Dungeness nuclear power stations, 2014 to 2025. (Small doses less than or equal to 0.005mSv are recorded as being 0.005mSv).

Year	Dose, mSv y-1
10% of the Dose limit	0.10
2014	0.021
2015	0.014
2016	0.021
2017	0.021
2018	0.022
2019	0.037
2020	0.012
2021	0.012
2022	0.011
2023	0.005
2024	0.010
2025	0.010

As in recent years, the dose to a high-rate consumer of locally grown foods was estimated to be less than 0.005mSv and was unchanged from recent years (Table 4.1). The dose to a local seafood consumer was estimated to be 0.010mSv in 2025, similar to that in 2024 (0.011mSv).

4.1.3.2. Gaseous discharges and terrestrial monitoring

Gaseous wastes are discharged via separate stacks to the local environment. The focus of the terrestrial sampling was the analyses of tritium, carbon-14 and sulphur-35 in milk and crops. The results of monitoring for 2025 are given in Table 4.4(a). Activity concentrations in many terrestrial foods are reported as ‘less than values’ (or close to the ‘less than value’). As in recent years, sulphur-35 was positively detected in grass. As was the case in 2024, tritium was not positively detected in food (potato) in 2025. As in recent years, carbon-14 was positively detected in locally produced milk at concentrations slightly above background in 2025. Tritium, gross alpha and gross beta concentrations in freshwater were below the investigation levels for drinking water in the Water Supply (Water Quality) (Amendment) 2018 Regulations (retained from the European Directive 2013/51) in 2025.

4.1.3.3. Liquid waste discharges and aquatic monitoring

Permitted discharges of radioactive liquid effluent from both power stations are made via separate outfalls to the English Channel. The draining of fuel ponds at Dungeness A was completed in 2019 and this removed the main source of aqueous waste discharges on site. As in 2024, the liquid discharge of sulphur-35 was reported as nil in 2025, as its presence in treated aqueous effluent has now fallen below detectable limits following cessation of electricity generation. Marine monitoring included gamma dose rate measurements, and analysis of seafood, seaweed, sediments and seawater. The results of monitoring for 2025 are given in Table 4.4(a) and Table 4.4(b). The caesium-137 concentrations in seafood are attributable to discharges from the stations, fallout from nuclear weapons testing and a long-distance contribution from Sellafield and La Hague nuclear fuel reprocessing facility in France. Due to the low concentrations detected in foods and marine materials, it is generally difficult to attribute the results to a particular source without any complementary forensic investigations. The low concentrations of transuranic nuclides in molluscs (scallop sample collected in 2025) were typical of values expected at sites remote from Sellafield. As in recent years, the 2025 tritium concentrations in seafood were all reported as ‘less than values’. Caesium-137 concentrations in sediment have remained low over the last decade (Figure 4.6). Unlike in recent years, caesium-137 was not positively detected in any sediments collected in 2025.

Figure 4.6. Caesium-137 concentration, in Bq kg^-1 (dry), in marine sediments near Dungeness nuclear power stations between 2014 and 2025.

Year	137Cs concentration Bq Kg-1 (dry)
2014	0.40
2015	0.46
2016	0.31
2017	0.24
2018	0.31
2019	0.28
2020	0.35
2021	0.30
2022	0.27
2023	0.56
2024	1.0
2025	0.26

4.1.4. Hartlepool, County Durham

Hartlepool Power Station is situated on the mouth of the Tees Estuary, on the north-east coast of England. This station, which is powered by twin AGRs, began operation in 1983. The power station in Hartlepool is expected to end power production in 2030. The most recent habits survey was undertaken in 2024 (Moore and others, 2025).

4.1.4.1. Doses to the public

The ‘total dose’ from all pathways and sources of radiation was 0.007mSv in 2025 (Table 4.1), which was less than 1% of the dose limit to members of the public and was unchanged from 2024. As in 2024, the representative person was an adult living near the site. The trend in ‘total dose’ over the period 2014 to 2025 is given in Figure 4.7. The ‘total doses’ in 2024 and 2025 were the lowest estimated in the last ten years.

Figure 4.7. ‘Total dose’, in mSv y^-1, at Hartlepool nuclear power station, 2014 to 2025.

Year	Dose, mSv y-1
10% of the Dose limit	0.10
2014	0.027
2015	0.022
2016	0.020
2017	0.031
2018	0.012
2019	0.013
2020	0.017
2021	0.012
2022	0.011
2023	0.015
2024	0.007
2025	0.007

A source-specific assessment for high-rate consumers of locally grown foodstuffs gave an exposure that was less than the ‘total dose’ in 2025 (Table 4.1). The estimated dose was less than 0.005mSv and down from 0.005mSv in 2024. The decrease in dose was mainly due to a lower concentration of carbon-14 in milk. The dose to a local fish and shellfish consumer (including external radiation but excluding naturally occurring radionuclides) was 0.007mSv in 2025 and was unchanged from 2024.

As in previous years, a source-specific assessment was not undertaken to determine the exposure from naturally occurring radionuclides in 2025 as discussed in previous RIFE reports (Environment Agency and others, 2022).

4.1.4.2. Gaseous discharges and terrestrial monitoring

Gaseous radioactive waste is discharged via stacks to the local environment. Gaseous discharges of carbon-14 decreased in 2025, compared to 2024 as a result of planned and unplanned outages. Analyses of tritium, carbon-14, sulphur-35 and gamma-emitting radionuclides were carried out in milk and crop samples. Samples of freshwater were also taken from boreholes. Data for 2025 are given in Table 4.5(a). Carbon-14 was detected in locally produced milk at concentrations slightly above the default value used to represent background. Tritium, and gross beta concentrations in freshwater were below the investigation levels for drinking water in the Water Supply (Water Quality) (Amendment) 2018 Regulations (retained from the European Directive 2013/51).

4.1.4.3. Liquid waste discharges and aquatic monitoring

Permitted discharges of radioactive liquid effluent are made to Tees Bay with non-radioactive trade effluents being discharged directly to the River Tees. Liquid discharges of tritium and sulphur-35 decreased in 2025 compared to 2024 due to planned and unplanned outages. Tritium discharges are directly related to power output and the reduction in liquid tritium discharges can be attributed to the increased time that the Hartlepool reactors were off-line undergoing maintenance or refuelling during outages.

Results of the aquatic monitoring programme conducted in 2025 are shown in Table 4.5(a) and Table 4.5(b). As in 2024, the carbon-14 concentrations measured in the mollusc samples (winkles) were found to be slightly above the expected background (Table A6.2). Carbon-14 concentrations in fish and crustaceans were generally higher in 2025, compared to those in 2024.

The analysis of technetium-99 in seaweed is used as a specific indication of the far-field effects of disposals to sea from Sellafield. As in previous years, technetium-99 was positively detected in seaweed, but was very low and significantly less than the peak concentration observed in 2008 (Environment Agency and others, 2019). Technetium-99 concentrations in seaweed are less than 1% of the equivalent concentrations near Sellafield. As in previous years, iodine-131 was positively detected in seaweed samples collected around the mouth of the River Tees Estuary in 2025. The detected values, as in previous years, are believed to originate from the therapeutic use of this radionuclide in local hospitals. Detectable concentrations of caesium-137 were mainly due to disposals from Sellafield and fallout from nuclear weapons testing. However, caesium-137 concentrations in sediment have remained low for several years (Figure 4.8). Overall, gamma dose rates over intertidal sediment in 2025 were similar (where comparisons can be made from similar ground types and locations), to those observed in recent years.

Figure 4.8. Caesium-137 concentration, in Bq kg^-1 (dry), in marine sediments near Hartlepool nuclear power station between 2014 and 2025.

Year	137Cs concentration Bq Kg-1 (dry)
2014	1.8
2015	1.4
2016	1.2
2017	1.3
2018	1.1
2019	1.5
2020	1.0
2021	0.91
2022	0.70
2023	0.76
2024	1.9
2026	4.2

In 2025, the reported polonium-210 and lead-210 concentrations in winkles from South Gare were consistent with values expected due to naturally occurring sources (given in Appendix 6, Table A6.1). As in previous years, a winkle sample could not be collected from the estuary entrance near Paddy’s Hole in 2025.

4.1.5. Heysham, Lancashire

Heysham Power Station is situated on the Lancashire coast, to the south of Morecambe and near the port of Heysham. This establishment comprises of 2 separate nuclear power stations, Heysham 1 and Heysham 2, each powered by twin AGRs. Heysham 1 commenced operation in 1983 and Heysham 2 began operating in 1988. It is estimated that Heysham 1 and 2 will continue to generate electricity until 2030. Disposals of radioactive waste from both stations are permitted via separate and adjacent outfalls to Morecambe Bay and via stacks. However, in RIFE, both stations are considered together for purposes of environmental monitoring, because the discharges from both sites impact on the same area.

The most recent habits survey was conducted in 2016 (Garrod and others, 2017), a new habits survey was conducted during the summer of 2026, the results are which are expected to be published in early 2027.

4.1.5.1. Doses to the public

The ‘total dose’ from all pathways and sources of radiation was 0.017mSv in 2025 (Table 4.1) or less than 2% of the dose limit for members of the public, similar to 2024 (0.016mSv). As in recent years, the representative person was an adult spending time over sediments. The small increase in ‘total dose’ in 2025 was mostly due to higher gamma dose rates measured over sand compared to those in 2024.

The trend in ‘total dose’ over the period 2014 to 2025 is given in Figure 4.9. The annual ‘total dose’ ranged between 0.010 and 0.025mSv and were below the dose limit.

Figure 4.9. ‘Total dose’, in mSv y^-1, at Heysham nuclear power stations, 2014 to 2025.

Year	Dose, mSv y-1
10% of the Dose limit	0.10
2014	0.023
2015	0.023
2016	0.019
2017	0.025
2018	0.010
2019	0.018
2020	0.010
2021	0.015
2022	0.016
2023	0.015
2024	0.016
2025	0.017

As in 2024, source-specific assessments for high-rate terrestrial food consumption, and from external exposure for turf cutting over salt marsh, give exposures that were less than the ‘total dose’ in 2025 (Table 4.1). The estimated dose for terrestrial food consumption was less than 0.005mSv in 2025 and unchanged from 2024. The estimated dose to the turf cutters was less than 0.005mSv in 2025 and unchanged from recent years. The dose to a local fisherman, who was considered to consume a large amount of seafood and was exposed to external radiation over intertidal areas, was 0.023mSv in 2025, which was approximately 2% of the dose limit for members of the public an increase from 0.020mSv in 2024 (Table 4.1). The main reason for the increase in dose was the same as that contributing to the ‘total dose’.

4.1.5.2. Gaseous discharges and terrestrial monitoring

Both stations discharge gaseous radioactive waste via stacks to the atmosphere. Gaseous discharges of carbon-14 from Heysham 2 decreased in 2025, compared to 2024. This was due to reduced power output from one of the reactors and reactor shut down as part of a graphite inspection. The monitoring programme for determining the effects of gaseous disposals was similar to that for other power stations. Data for 2025 are given in Table 4.6 (a). As in recent years, sulphur-35 was positively detected in silage in 2025. As in 2024, the carbon-14 concentrations in milk were above the default value used to represent background in 2025 but were lower than those observed in 2024. Tritium, gross alpha and gross beta concentrations in freshwater were below the investigation levels for drinking water in the Water Supply (Water Quality) (Amendment) 2018 Regulations (retained from the European Directive 2013/51).

4.1.5.3. Liquid waste discharges and aquatic monitoring

Permitted discharges of radioactive liquid effluent are made via outfalls into Morecambe Bay. Liquid discharges from Heysham 1 and 2, in 2025 were broadly similar in comparison with recent years.

The monitoring programme for the effects of liquid disposals included sampling of fish, shellfish, sediment, seawater and measurements of gamma dose rates. For completeness, the data considered in this section include all of those for Morecambe Bay. A substantial part of the programme is in place to monitor the effects of Sellafield disposals. The results for 2025 are given in Table 4.6(a) and Table 4.6(b). In general, activity concentrations in 2025 were similar (in comparison to those in recent years) and the effect of liquid disposals from Heysham was difficult to detect above the Sellafield background, based upon the greater historical discharges from Sellafield and monitoring data prior to operation of Heysham 1 and 2. Plutonium radionuclides and americium-241 concentrations in mussels and concentrations of technetium-99 in marine samples originating from Sellafield discharges were similar to those observed in recent years. As in recent years, strontium-90 was detected at low concentrations (reported as just above, or close to, the ‘less than value’) in food samples collected in 2025. Gamma dose rates measured over sand were slightly higher in 2025 (in comparison with 2024). Concentrations of caesium-137 in sediment samples near the Heysham nuclear power stations is given in Figure 4.10 over the period 2014 to 2025. There has been variability from year to year, with a large Sellafield influence.

Figure 4.10. Caesium-137 concentration, in Bq kg^-1 (dry), in marine sediments near Heysham nuclear power stations between 2014 and 2025.

Year	137Cs concentration Bq Kg-1 (dry)
2014	33
2015	16
2016	36
2017	27
2018	24
2019	28
2020	23
2021	48
2022	40
2023	53
2024	25
2025	30

4.1.6. Hinkley Point, Somerset

The Hinkley Point Power Station sites are situated on the Somerset coast, west of the River Parrett estuary. There are 2 separate stations, A and B, that include 2 Magnox reactors and 2 AGRs, respectively. Hinkley Point A started electricity generation in 1965 and ceased in 1999. This station completed defuelling in 2004 and is undergoing decommissioning. Hinkley Point B ended power generation and entered its defuelling phase in 2022. The defuelling phase was completed in 2025, and the site was granted Fuel Free Verification status by ONR, allowing formal decommissioning to begin. The permit limits for gaseous discharges of sulphur-35, argon-41, iodine-131 and liquid discharges of sulphur-35 from Hinkley Point B were revised in December 2025. A single environmental monitoring programme covers the effects of the 2 power stations, because the discharge effects from both sites impact on the same area. The most recent habits survey was conducted in 2024 (Greenhill and others, 2025).

The construction of the 2 new generation EPR^TM reactors continues at Hinkley Point C. Summary details of earlier environmental permits issued (by the Environment Agency), the pre-construction safety case (approved by the ONR), the planning consents granted, and other approvals, are available in earlier RIFE reports (for example (Environment Agency and others, 2019)) and from Hinkley Point decisions on environmental permit applications for a proposed new nuclear power station. The reactor pressure vessels were installed at Hinkley Point C in 2024 and 2026 with operation of the first reactor expected in 2030. The latest information on the project can be found at: Hinkley Point on Gov.uk.

4.1.6.1. Doses to the public

In 2025, the ‘total dose’ from all pathways and sources of radiation was 0.011mSv (Table 4.1), or approximately 1% of the dose limit to members of the public. This is a decrease from 0.014mSv in 2024. The representative person was an adult spending time over sediments (unchanged from recent years). The decrease in ‘total dose’ was primarily due to gamma dose rates being measured over different substrates at Stolford.

The trend in ‘total dose’ over the period 2014 to 2025 is given in Figure 4.11. The annual ‘total dose’ ranged between 0.011 and 0.041mSv and were below the dose limit.

Figure 4.11. ‘Total dose’, in mSv y^-1, at Hinkley Point nuclear power stations, 2014 to 2025.

Year	Dose, mSv y-1
10% of the Dose limit	0.10
2014	0.022
2015	0.016
2016	0.013
2017	0.032
2018	0.041
2019	0.021
2020	0.023
2021	0.030
2022	0.015
2023	0.032
2024	0.014
2025	0.011

As in 2024, the source-specific assessment for a high-rate consumer of locally grown food gave an exposure that was less than the ‘total dose’ in 2025 (Table 4.1). The dose to this consumer of locally grown food was less than 0.005mSv in 2025 (unchanged from 2024). A source-specific assessment for local people who consume high rates of seafood and are exposed to external radiation over intertidal area gave an exposure of 0.013mSv, similar to that in 2024 (0.014mSv). This dose estimate also includes the effects of (historical) discharges of tritium from the Maynard Centre, the former GE Healthcare Limited plant at Cardiff^{[footnote 9]} and uses an increased dose coefficient (see Appendix 5).

4.1.6.2. Gaseous discharges and terrestrial monitoring

Gaseous radioactive waste is discharged via separate stacks to the local environment. Gaseous discharges in 2025 were similar in comparison with 2024. Analyses of milk, fruit, honey and crops were undertaken to measure activity concentrations of tritium, carbon-14, sulphur-35 and cobalt-60. Local reservoir water samples were also analysed. Data for 2025 are given in Table 4.7(a). In 2025, tritium was positively detected in the blackberry sample. Activity concentrations of cobalt-60 in all terrestrial materials were reported as ‘less than values’. As in recent years, sulphur-35 was positively detected in food samples (honey and barley) in 2025. The carbon-14 concentrations in locally produced milk were higher than values observed in 2024. Tritium, gross alpha and gross beta concentrations in reservoir water were below the investigation levels for drinking water in the Water Supply (Water Quality) (Amendment) 2018 Regulations (retained from the European Directive 2013/51).

4.1.6.3 Liquid waste discharges and aquatic monitoring

Permitted discharges of radioactive liquid effluent from both power stations are made via separate outfalls into the Bristol Channel. Analyses of seafood and marine indicator materials and measurements of external radiation were conducted over intertidal areas. The environmental results for 2025 are given in Table 4.7(a) and Table 4.7(b). Overall, activity concentrations observed in seafood collected from the Bristol Channel were generally similar to those in previous years. Unlike in 2024, tritium was not positively detected in seafood in 2025. Concentrations of other radionuclides in the aquatic environment represent the combined effect of releases from these stations, plus other establishments that discharge into the Bristol Channel. Other contributors to the aquatic environment are Sellafield, and fallout from Chernobyl and nuclear weapons testing. The concentrations of transuranic nuclides in seafoods were of negligible radiological significance. Trends of caesium-137 concentrations in sediment are shown in Figure 4.12. The high concentrations of strontium-90 and caesium-137 observed in 2024 prompted an extensive investigation of the full process from sampling to data reporting. Although the main cause could not be confirmed, the impact on the ‘total dose’ and external dose was found to be limited (Environment Agency and others, 2025).

Figure 4.12. Caesium-137 concentration, in Bq kg^-1 (dry), in marine sediments near Hinkley Point nuclear power stations between 2014 and 2025.

Year	137Cs concentration Bq Kg-1 (dry)
2014	15
2015	11
2016	10
2017	13
2018	12
2019	12
2020	20
2021	9.2
2022	7.6
2023	6.9
2024	79
2025	6.2

4.1.7. Sizewell, Suffolk

The 2 Sizewell Power Stations are located on the Suffolk coast, near Leiston. Sizewell A has 2 Magnox reactors that ceased electricity generation in 2006. Defuelling commenced in 2007 and was completed in 2014. Sizewell B, powered by one reactor, is the only commercial Pressurised Water Reactor power station in the UK. The Sizewell B power station began operation in 1995, and the end of power generation is now scheduled for 2055, as a 20-year operational extension was announced in July 2026 (UK Government 2026). The most recent habits survey was conducted in 2025 (Moore, Clyne, Greenhill, Limbach, and others, 2026). One of the findings from the survey was that no houseboat occupancy was identified, therefore the source-specific assessment for this pathway calculated in previous years was discontinued.

Sizewell C Limited intends to construct 2 EPR^TM reactors at a site north of the existing Sizewell B site. In 2022, the Secretary of State for the Department of Business, Energy and Industrial Strategy announced that the Sizewell C project had been granted its Development Consent Order. In 2023, the Environment Agency granted the permit for discharging and disposing of radioactive waste in the environment. In 2024, ONR granted its nuclear site license. Further information can be found at: Sizewell nuclear regulation on gov.uk. In July 2025, the UK Government confirmed a final investment decision for the project.

Gaseous and liquid discharges of radioactivity from Sizewell C are not expected to begin until active commissioning of the station in the mid-2030s.

4.1.7.1. Doses to the public

The ‘total dose’ from all pathways and sources of radiation was 0.010mSv in 2025 (Table 4.1) or 1% of the dose limit to members of the public. This is a decrease from 0.014mSv in 2024. The representative person in 2025 was an adult living close to the site, unchanged from recent years. The decrease in ‘total dose’ was mostly attributed to a lower estimate of direct radiation in 2025. The trend in ‘total dose’ over the period 2014 to 2025 is given in Figure 4.13. Any variation in ‘total dose’ from year to year was largely due to a change in the contribution from direct radiation from the site, which has been low in recent years. The ‘total dose’ has declined (reduced by a factor of 5 or 6), following the closure of the Magnox reactors at Sizewell A in 2006 (Environment Agency and others, 2018).

Figure 4.13. ‘Total dose’, in mSv y^-1, at Sizewell nuclear power stations, 2014 to 2025.

Year	Dose, mSv y-1
10% of the Dose limit	0.10
2014	0.020
2015	0.021
2016	0.021
2017	0.021
2018	0.026
2019	0.010
2020	0.017
2021	0.016
2022	0.011
2023	0.010
2024	0.014
2025	0.010

As in recent years, source-specific assessments for both a high-rate consumer of locally grown foodstuffs, and of fish and shellfish gave exposures that were lower than the ‘total dose’ in 2025 (less than or equal to 0.005mSv (Table 4.1)).

4.1.7.2. Gaseous discharges and terrestrial monitoring

Gaseous discharges in 2025 were very similar to those reported in 2024.

The results of the terrestrial monitoring in 2025 are shown in Table 4.8(a). As in recent years, gamma-ray spectrometry and radiochemical analysis of tritium and sulphur-35 in milk and crops generally showed very low concentrations of artificial radionuclides near the power stations in 2025. In 2025, carbon-14 concentrations in produced milk were found to be above the estimated background level and slightly higher than those in 2024. As in recent years, sulphur-35 was positively detected at a very low concentration in a grass sample collected in 2025. Sulphur-35 was also positively detected in a potato sample in 2025, unlike in 2024. As in recent years, tritium concentrations in local freshwater were reported as ‘less than values’ in 2025. Tritium, gross alpha and gross beta concentrations in surface water were below the investigation levels for drinking water in the Water Supply (Water Quality) (Amendment) 2018 Regulations (retained from the European Directive 2013/51).

4.1.7.3. Liquid waste discharges and aquatic monitoring

Permitted discharges of radioactive liquid effluent are made via outfalls to the North Sea. Liquid discharges of tritium from Sizewell B decreased in 2025, in comparison with those in 2024. These discharges follow a cyclical profile which follow the 18-month outage cycle, with tritium discharges peaking just before the outage (as part of the outage enabling works). The project to drain the fuel storage pond at Sizewell A was completed in 2019. This has resulted in a significant reduction in liquid effluent generation at Sizewell A. As part of the aquatic programme, analysis of seafood, sediment, and seawater, and measurements of gamma dose rates were conducted in intertidal areas. Data for 2025 are given in Table 4.8(a) and Table 4.8(b). As in 2024, tritium was not positively detected in seafood in 2025. As in recent years, concentrations of strontium-90 observed in sediment samples were all reported as ‘less than values’ and concentrations of caesium-137 were very low. Caesium-137 concentrations in sediment have remained low over the last decade and are generally decreasing over time (Figure 4.14). Overall, gamma radiation dose rates over intertidal areas were difficult to distinguish from the natural background and were similar to those reported in recent years.

Figure 4.14. Caesium-137 concentration, in Bq kg^-1 (dry), in marine sediments near Sizewell nuclear power stations between 2014 and 2025.

Year	137Cs concentration Bq Kg-1 (dry)
2014	5.7
2015	6.7
2016	5.8
2017	5.8
2018	5.5
2019	4.6
2020	4.8
2021	4.3
2022	4.1
2023	4.4
2024	4.1
2025	4.4

4.2. Scotland

4.2.1. Chapelcross, Dumfries and Galloway

Chapelcross was Scotland’s first commercial nuclear power station. It has 4 Magnox reactors and is located near the town of Annan in Dumfries and Galloway. After 45 years of continuous operation, electricity generation ceased in 2004, and the station has since been undergoing decommissioning. Defuelling of the reactors began in 2008 and was completed during 2013. The major hazards remaining on the site are being addressed during the decommissioning phase.

Habits surveys have been undertaken to investigate aquatic and terrestrial exposure pathways. The most recent habits survey for Chapelcross was conducted in 2022. In 2024, a separate habits survey was also conducted to determine the consumption and occupancy rates by members of the public on the Dumfries and Galloway coast. Copies of the most recent habits surveys are available from SEPA by emailing RSEnquiries@sepa.org.uk. The results of this survey are used to determine the potential exposure pathways relating to permitted liquid discharges from the Sellafield nuclear site in Cumbria (see Section 3.3.1).

In 2025, the site applied for a variation to their EASR permit. The application was for increasing the gaseous discharge limits for tritium associated with the site’s Intermediate Waste Storage Facility (ISF), to support ongoing decommissioning activities.

4.2.1.1. Doses to the public

The ‘total dose’ from all pathways and sources of radiation was 0.007mSv in 2025 (Table 4.1), or less than 1% of the dose limit to members of the public. This is unchanged from 2024. As in recent years, the representative person was an infant consuming locally produced milk at high rates. The trend in ‘total dose’ over the period 2014 to 2025 is given in Figure 4.15, doses are generally low, with a small peak observed in 2017 (still less than 5% of the dose limit to members of the public).

Figure 4.15. ‘Total dose’, in mSv y^-1, at Chapelcross nuclear power station, 2014 to 2025.

Year	Dose, mSv y-1
10% of the Dose limit	0.10
2014	0.014
2015	0.022
2016	0.026
2017	0.035
2018	0.019
2019	0.007
2020	0.018
2021	0.018
2022	0.009
2023	0.010
2024	0.007
2025	0.007

As in recent years, source-specific assessments for a high-rate consumer of locally grown food, and for a seafood (salmon) and wildfowl consumer, gave exposures that were less than the ‘total dose’ in 2025 (Table 4.1). The dose for the terrestrial food consumer was estimated to be 0.006mSv in 2025 and unchanged from 2024. The dose for the seafood and wildfowl consumer was 0.006mSv in 2025 and up from 2024 (less than 0.005mSv). The increase in dose in 2025 was mostly due to the use of an indirect method for estimating an average gamma dose rate via sediment analysis (instead of the use of direct dose rate measurements over salt marsh in 2024). Crustacean consumption was not identified in the recent habits survey.

Doses from the presence of artificial radionuclides in marine materials in the Chapelcross vicinity are mostly due to the effects of Sellafield discharges and are consistent with values expected at this distance from Sellafield.

4.2.1.2. Gaseous discharges and terrestrial monitoring

Gaseous radioactive waste is discharged via stacks to the local environment.

Terrestrial monitoring consisted of the analysis of a variety of foods, including milk, fruit, crops as well as grass, soil and freshwater samples, for a range of radionuclides. Air samples at 3 locations were also monitored to investigate the inhalation pathway. The results of terrestrial food and air monitoring in 2025 are given in Table 4.9(a) and Table 4.9(c). Carbon-14 concentrations in milk were similar to those observed in 2024. As in recent years, americium-241 concentrations ‘in all terrestrial food, and grass samples were all reported as ‘less than values’.

As in recent years, tritium was positively detected in the freshwater sample collected at Gullielands Burn. However, tritium, gross alpha and gross beta concentrations in all freshwater samples were well below the investigation levels for drinking water in the Water Supply (Water Quality) (Amendment) 2018 Regulations (retained from the European Directive 2013/51). Activity concentrations in air samples at locations near to the site (Table 4.9(c)) were reported as ‘less than values’ (or close to the ‘less than value’). Solid waste transfers in 2025 are also given in Appendix 1 (Table A1.4).

4.2.1.3. Liquid waste discharges and aquatic monitoring

Radioactive liquid effluents are discharged to the Solway Firth. As in 2024, radioactive effluent was discharged from the site on a number of occasions in support of ongoing decommissioning activities in 2025. Samples of seawater and seaweed (‘Fucus vesiculosus’), used as environmental indicators, were collected in addition to shrimps, mussels, fish (salmon and trout), sediments and measurements of gamma dose rates. Data for 2025 are given in Table 4.9(a) and Table 4.9(b). Concentrations of artificial radionuclides in marine materials in the Chapelcross vicinity are mostly due to the effects of Sellafield discharges and are consistent with values expected at this distance from Sellafield. Concentrations of most radionuclides remained similar to those detected in recent years. Unlike in previous years, europium-155 was not positively detected in sediment samples collected in 2025.

As in previous years, concentrations of caesium-137, plutonium radionuclides and americium-241 were enhanced in sediment samples taken close to the pipeline in 2025. The average concentration of caesium-137 in sediments analysed in 2025 was higher than in 2024 and is known to be largely due to Sellafield discharges (Figure 4.16). In 2025, gamma dose rates over intertidal sediment were generally lower to those in 2024 (where comparisons can be made). As in previous years, measurements of the contact beta dose rate on sediments were reported as ‘less than values’ in 2025.

Figure 4.16. Caesium-137 concentration, in Bq kg^-1 (dry), in marine sediments near Chapelcross nuclear power station between 2014 and 2025.

Year	137Cs concentration Bq Kg-1 (dry)
2014	72
2015	72
2016	59
2017	55
2018	56
2019	58
2020	97
2021	70
2022	39
2023	61
2024	47
2025	43

Between 1992 and 2009, several particles were found at the end of the discharge outfall consisting of limescale originating from deposits within the pipeline. The site operator continues to monitor this area frequently and no particles were found during 2025 (as for the previous years). The relining of the pipeline and grouting at strategic points, which was undertaken between 2009 and 2010, has reduced the potential for particles to be released.

4.2.2. Hunterston, North Ayrshire

Hunterston Power Station is located on the Ayrshire coast near West Kilbride and consists of 2 separate nuclear power stations - Hunterston A and Hunterston B.

Hunterston A was powered by 2 Magnox reactors until it ceased electricity production in 1990 and is now being decommissioned by NRS. Defuelling was completed in 1995. Decommissioning activities continue to focus on 2 major areas: the ongoing decommissioning of the cartridge (nuclear fuel) cooling pond; and making progress towards ensuring that all higher activity waste is stored in a passively safe manner.

Most of the radioactivity in liquid effluent discharged from the Hunterston A site over the last few years has arisen from the cartridge cooling pond. The draining of the cartridge cooling pond is now largely complete. However, there is still a need to manage the remaining radioactive sludges from several areas associated with the pond.

In 2023, SEPA received an application from NRS to vary the permit, made under the Environmental Authorisations (Scotland) Regulations 2018 (EASR), for the Hunterston A site. The variation application includes the addition of the Solid Intermediate Level Waste Encapsulation plant (SILWE) facility discharge stack to the site permit, and an increase to the site gaseous discharge limits. The permit variation application went to public consultation in late October 2024.

In 2024, SEPA received another application from NRS to amend its EASR permit. The requested changes include removing the minimum flow requirement during aqueous discharges (7m³ s^-1) and eliminating the tidal window restriction (one hour after high tide to one hour before low tide). The discharge point will remain unchanged, and no other limits will be altered.

In terms of safe management of legacy higher activity waste at Hunterston A, NRS are in the process of commissioning the SILWE. The Wet Intermediate Level Waste Retrieval and Encapsulation Plant (WILWREP) has finalised modifications for processing radioactively contaminated acid wastes and is currently going through active commissioning. Processing of the legacy higher activity waste, present at the Hunterston A site will be processed through either SILWE or WILWREP, with the current plans being to make safe by encapsulating it in a grout mixture. The encapsulated waste will then be transferred to the Intermediate Level Waste Store (ILWS) for storage.

Hunterston B was powered by a pair of AGRs, referenced as Reactors 3 and 4. Electricity production was ceased in 2022, and defuelling operations were undertaken by EDF Energy Nuclear Generation Limited. Both reactors are now defuelled, and the site has been declared as fuel free. The past year has been spent transitioning to a decommissioning structure as well as preparing to transfer to the NDA Estate and to be decommissioned by NRS. Both gaseous and liquid discharges are much lower following defuelling than during the operational phase.

Hunterston B has also applied to vary its permit for radioactive substances activities to remove the minimum flow during aqueous discharges (7m³ s^-1) as well as the tidal window (one hour after high tide to one hour before low tide). The discharge point will remain unchanged, and no other limits will be altered.

In terms of safe management of legacy higher activity waste at Hunterston B, the preferred option is to use the Intermediate Level Waste Store on Hunterston A. The station continues to develop the optimal solution for the Operational Waste Processing Facility (OWPF), which will manage the higher activity wastes arising from the station’s operational life. The Decommissioning Waste Processing Facility will be refurbished and used to manage the lower activity waste arising from the decommissioning phase, however, Reinforced Autoclaved Aerated Concrete (RAAC) has been found in part of the roof which will require a management strategy in order to progress the refurbishment of the Decommissioning Waste Processing Facility.

Environmental monitoring in the area considers the effects of both Hunterston A and Hunterston B sites together. The most recent habits survey was conducted in 2024 and is available on SEPA Habits surveys or by emailing RSEnquiries@sepa.org.uk.

4.2.2.1 Doses to the public

The ‘total dose’ from all pathways and sources of radiation was 0.007mSv in 2025 or less than 1% of the dose limit (Table 4.1) to members of the public. This is similar to the dose in 2024 (0.006mSv). The representative person was prenatal children of an adult living near the site unchanged from 2024. The trend in ‘total dose’ over the period 2014 to 2025 is given in Figure 4.17, doses have generally decreased since 2018, with some variability observed over this period.

Figure 4.17. ‘Total dose’, in mSv y^-1, at Hunterston nuclear power stations, 2014 to 2025. (Small doses less than or equal to 0.005mSv are recorded as being 0.005mSv).

Year	Dose, mSv y-1
10% of the Dose limit	0.10
2014	0.021
2015	0.025
2016	0.021
2017	0.023
2018	0.005
2019	0.005
2020	0.005
2021	0.006
2022	0.005
2023	0.013
2024	0.006
2025	0.007

The estimated dose for seafood consumption was 0.008mSv in 2025 which was less than 1% of the dose limit for members of the public of 1mSv and unchanged from 2025.

The estimated dose for a terrestrial food consumer was 0.025mSv in 2025, which was less than 3% of the dose limit for members of the public of 1mSv and up compared to that in 2024 (0.009mSv). The reason for the increase in dose was mainly due to a significantly higher caesium-137 concentration in the pheasant sample selected in 2025 (54Bq kg^-1).

4.2.2.2. Gaseous discharges and terrestrial monitoring

Gaseous discharges are made via separate discharge points from the Hunterston A and Hunterston B stations. Gaseous radioactive waste discharges from the site remain low in comparison to current site limits which are recognised as being low in comparison to other NRS sites.

There is a substantial terrestrial monitoring programme which includes the analyses of a comprehensive range of wild and locally produced foods. In addition, air, freshwater, grass and soil are sampled to provide background information. The results of terrestrial food and air monitoring in 2025 are given in Table 4.10(a) and Table 4.10(c). The concentrations of radionuclides in air, milk, crops and fruit were generally low and similar to those in previous years (where comparisons can be made). The concentration of ceasium-137 in pheasant was significantly higher in 2025 in comparison to that in 2024. As in recent years, sulphur-35 was positively detected in grass in 2025. Tritium, gross alpha and gross beta concentrations in freshwater were below the investigation levels for drinking water in the Water Supply (Water Quality) (Amendment) 2018 Regulations (retained from the European Directive 2013/51).

All activity concentrations in air at locations near to the site (Table 4.10(c)) were reported as ‘less than values’ (or close to the ‘less than value’). Solid waste transfers in 2025 are also given in Appendix 1 (Table A1.4).

4.2.2.3. Liquid waste discharges and aquatic monitoring

Authorised liquid discharges from both Hunterston stations are made to the Firth of Clyde via the Hunterston B station’s cooling water outfall. The primary source of liquid discharges from Hunterston A, is the cartridge cooling pond, draining of which is nearly complete (reducing the radiological hazards on site), which is supported by nil discharges of alpha emitting radionuclides and plutonium-241.

The main part of the aquatic monitoring programme consists of sampling of fish and shellfish and the measurement of gamma and beta dose rates on the foreshore. Samples of sediment, seawater and seaweed are analysed as environmental indicator materials.

The results of aquatic monitoring in 2025 are shown in Table 4.10(a) and Table 4.10(b). The concentrations of artificial radionuclides in the marine environment are predominantly due to Sellafield discharges, the general values being consistent with those to be expected at this distance from Sellafield. As in recent years, the concentrations of Sellafield derived technetium-99 in crabs and lobsters around Hunterston were low. All cobalt-60 concentrations in sediments were reported as ‘less than value’ in 2025. In 2025, plutonium and americium-241 concentrations in seafood were generally similar to those observed in recent years. Gamma dose rates were generally similar in 2025, in comparison to those observed in recent years. Measurements of the beta dose rates over sediments and rocks were all reported as ‘less than values’ in 2025. Caesium-137 concentrations in sediment have remained low over the last decade (Figure 4.18).

Figure 4.18. Caesium-137 concentration, in Bq kg^-1 (dry), in marine sediments near Hunterston nuclear power stations between 2014 and 2025.

Year	137Cs concentration Bq Kg-1 (dry)
2014	4.7
2015	3.6
2016	5.6
2017	3.9
2018	3.9
2019	4.3
2020	3.8
2021	5.3
2022	4.1
2023	3.4
2024	4.3
2025	2.6

4.2.3. Torness, East Lothian

Torness Power Station is located near Dunbar on the east coast of Scotland. The station is powered by twin AGRs and began operation at the end of 1987. The current anticipated date for end of generation is 2030, however, EDF keeps operational dates under constant review.

The gaseous and liquid discharges from the site are given in Appendix 1.

The most recent habits survey, to determine the consumption and occupancy rates by members of the public was published in 2025 and is available on SEPA’s website SEPA Habits surveys. Copies can also be requested from SEPA by emailing RSEnquiries@sepa.org.uk.

4.2.3.1. Doses to the public

In 2025, the ‘total dose’ from all pathways and sources of radiation was 0.010mSv (Table 4.1), or 1% of the dose limit to members of the public. This is similar to the dose in 2024 (0.011mSv). In 2025, the representative person was a prenatal child of a local inhabitant consuming domestic fruits and unchanged from recent years. The trend in ‘total dose’ over the period 2014 to 2025 is given in Figure 4.19. The decrease in ‘total dose’ from 2018 reflected a downward trend in the reported direct radiation, thereafter ‘total dose’ has remained broadly similar, from year to year, and were low.

Figure 4.19. ‘Total dose’, in mSv y^-1, at Torness nuclear power station, 2014 to 2025. (Small doses less than or equal to 0.005mSv are recorded as being 0.005mSv).

Year	Dose, mSv y-1
10% of the Dose limit	0.10
2014	0.020
2015	0.020
2016	0.021
2017	0.021
2018	0.005
2019	0.005
2020	0.006
2021	0.005
2022	0.006
2023	0.007
2024	0.011
2025	0.010

The source-specific assessment for a high-rate consumer (infant) of terrestrial food gave an exposure that was 0.006mSv in 2025 (Table 4.1) and similar to that in 2024 (0.007mSv). The estimated dose to a high consumer of local fish and shellfish was less than 0.005mSv in 2025, or less than 0.5% of the dose limit for members of the public of 1mSv, and unchanged from that in recent years.

4.2.3.2. Gaseous discharges and terrestrial monitoring

A variety of foods, including milk, crops, fruit, and game as well as grass, soil and freshwater samples, were measured for a range of radionuclides. Air sampling at 3 locations was undertaken to investigate the inhalation pathway. The results of terrestrial food and air monitoring in 2025 are given in Table 4.11(a) and Table 4.11(c). Activity concentrations in many terrestrial foods are reported as ‘less than values’ (or close to the ‘less than value’). The carbon‑14 concentrations in locally produced milk were close to the default value used to represent background. Caesium-137 was positively detected in soil, but at low concentrations. As in recent years, americium-241 concentrations in all terrestrial food and soil samples (measured by gamma–ray spectrometry) were reported as ‘less than values’ in 2025. The tritium, gross alpha and gross beta concentrations in freshwater were well below the investigation levels for drinking water in the Water Supply (Water Quality) (Amendment) 2018 Regulations (retained from the European Directive 2013/51). Measured concentrations of radioactivity in air, at locations near to the site, were all reported as ‘less than values’ or close to the ‘less than values’ in 2025 (Table 4.11(c)). Solid waste transfers in 2025 are also given in Appendix 1 (Table A1.4).

4.2.3.3. Liquid waste discharges and aquatic monitoring

Discharges of authorised liquid radioactive wastes are made to the Firth of Forth. Seafood, seaweed, sediment, and seawater samples were collected in 2025. Measurements were also made of gamma dose rates over intertidal areas, supported by analyses of sediment, and beta dose rate measurements on fishing gear. The results of the aquatic monitoring in 2025 are shown in Table 4.11(a) and Table 4.11(b). Concentrations of artificial radionuclides were mainly due to the distant effects of Sellafield discharges, and fallout from Chernobyl and nuclear weapons testing. Cobalt-60 was only detected positively in winkles and seaweeds collected near the main discharge pipeline and at Thorntonloch in 2025. This activation product was likely to have originated from the station. Technetium-99 concentrations in marine samples were similar to those in recent years. Overall, caesium-137 concentrations in sediments have remained low over the last decade (Figure 4.20). Gamma dose rates over intertidal areas were generally indistinguishable from natural background and were similar to those measured in recent years. Measurements of the contact beta dose rate on fisher’s pots were reported as ‘less than values’ in 2025.

Figure 4.20. Caesium-137 concentration, in Bq kg^-1 (dry), in marine sediments near Torness nuclear power station between 2014 to 2025.

Year	137Cs concentration Bq Kg-1 (dry)
2014	1.2
2015	3.6
2016	0.87
2017	3.0
2018	1.0
2019	0.96
2020	0.93
2021	0.82
2022	0.80
2023	0.59
2024	0.80
2025	0.63

4.3. Wales

4.3.1. Trawsfynydd, Gwynedd

Trawsfynydd Power Station is located inland on the northern bank of Llyn Trawsfynydd in Eryri (Snowdonia) National Park, North Wales and was powered by 2 Magnox reactors. Trawsfynydd stopped generating electricity in 1991. Defuelling of the reactors was completed in 1995, and the station is being decommissioned. As part of NDA’s site-specific approach to decommissioning, Trawsfynydd was selected as the lead location, where the reactors will be dismantled without a long period of care and maintenance (Nuclear Decommissioning Authority 2021). The most recent habits survey was undertaken in 2018 (Greenhill, Clyne & Moore 2019).

4.3.1.1. Doses to the public

The ‘total dose’ from all pathways and sources of radiation was 0.015mSv in 2025 (Table 4.1), which was less than 2% of the dose limit to members of the public. This is an increase from 0.010mSv in 2024. The representative person in 2025 was an adult exposed to external radiation over lake sediments and was unchanged from recent years. The increase in ‘total dose’ was mostly attributed to a higher mean caesium-137 concentration in sediments collected from the lake shore near a café and near the main discharge pipeline (and hence calculated gamma dose rate over lacustrine sediments) in 2025. The trend in ‘total dose’ over the period 2014 to 2025 is given in Figure 4.21, with variations in recent years due to estimates of gamma dose rate over lacustrine sediments.

Figure 4.21. ‘Total dose’, in mSv y^-1, at Trawsfynydd nuclear power station, 2014 to 2025. (Small doses less than or equal to 0.005mSv are recorded as being 0.005mSv).

Year	Dose, mSv y-1
10% of the Dose limit	0.10
2014	0.013
2015	0.014
2016	0.019
2017	0.024
2018	0.017
2019	0.005
2020	0.012
2021	0.010
2022	0.009
2023	0.007
2024	0.010
2025	0.015

The dose to an angler (who consumes large quantities of fish and spends long periods of time in the location being assessed) was 0.012mSv in 2025 (Table 4.1), which was approximately 1% of the dose limit for members of the public of 1mSv and an increase from 2024 (0.007mSv). The main reason for the increase in dose was the same as for the ‘total dose’. The activity concentrations observed in lake sediments are used to calculate an external dose rate due to the difficulty in establishing the increase in measured dose rates above natural background rates. The dose to infants (1-year-old) consuming terrestrial food was 0.021mSv, or approximately 2% of the dose limit. This was lower than in 2024 (0.038mSv) because of a lower limit of detection for americium-241 in milk samples collected in 2025.

4.3.1.2. Gaseous discharges and terrestrial monitoring

The results of the terrestrial programme, for local food (including milk) and grass samples in 2025, are shown in Table 4.12(a). Concentrations of activity in all terrestrial samples were low. As in 2024, tritium concentrations in all milk samples were reported as ‘less than values’ in 2025. As in recent years, carbon-14 concentrations in milk were reported just above the background concentration. Measured activities for caesium-137 in all terrestrial samples were reported as ‘less than values’ (or close to the ‘less than value’) in 2025. The most likely source of small amounts of caesium-137 is fallout from Chernobyl and nuclear weapons testing, though it is conceivable that a small contribution may be made by re-suspension of lake activity. In recognition of this potential mechanism, monitoring of transuranic radionuclides, which are also associated with liquid discharges from the site (Ministry of Agriculture Fisheries and Food 1993), was also conducted on an apple sample. In 2025, detected activities of transuranic radionuclides in apples were low and generally similar to observations in other areas of England and Wales, where activity was attributable to fallout from nuclear weapons testing. Therefore, there was no direct evidence of re-suspension of activity in sediment from the lake shore contributing to increased exposure from transuranic radionuclides in 2025.

4.3.1.3. Liquid waste discharges and aquatic monitoring

Discharges of liquid radioactive waste are made to a freshwater lake, making the power station unique in UK terms. The aquatic monitoring programme was directed at consumers of freshwater fish caught in the lake and external exposure over the lake shoreline; the important radionuclides being caesium-137 and, to a lesser extent, strontium-90. Freshwater and sediment samples were also analysed in 2025. Brown and rainbow trout were found to be the species regularly consumed in past habits surveys. Most brown trout are indigenous to the lake, but rainbow trout are introduced from a hatchery. Due to the limited period that they spend in the lake, introduced fish generally exhibit lower caesium-137 concentrations than indigenous fish.

Data for 2025 are given in Table 4.12(a) and Table 4.12(b). Most activity concentrations in fish and sediments result from historical discharges, due to inefficient dispersion and binding to sediments (Ministry of Agriculture Fisheries and Food 1993). As in recent years, due to sample availability, only rainbow trout samples were collected in 2025. The most recent brown trout sample to be collected was in 2015 and the concentration of caesium-137 was the lowest reported value for fish indigenous to the lake (Environment Agency and others, 2016). As in previous years, caesium-137 concentrations in water samples are reported as ‘less than values’ in 2025. Concentrations in the water column are predominantly maintained by processes that release activity (such as remobilisation) from near surface sediments. Caesium-137 concentrations in lake sediments were slightly lower to those observed in 2024 at all sampling locations apart from the sediment collected near the main discharge pipeline, which exhibited a caesium-137 concentration of 350Bq kg^-1 (compared to a maximum of 320Bq kg^-1 observed in a sediment sample collected in 2024 on the lake shore near a café). Americium-241 was also positively detected in the sediment sample collected near the main discharge pipeline (5.3Bq kg^-1). In previous years’ monitoring programmes, it has been demonstrated that these concentrations increase with depth beneath the sediment surface. The concentrations of strontium-90 in all sediment samples collected in 2025 were reported as ‘less than values’. Unlike in 2024, plutonium-238 was positively detected in sediment sample (collected near the main discharge pipeline). As in recent years, plutonium-239+240 was also positively detected in a sediment sample (collected on the lake shore near a café and near the main discharge pipeline). Strontium-90 and transuranic concentrations in fish continued to be very low in 2025 and it is the effects of caesium-137 that dominate the external radiation pathways.

In the lake itself, there remains clear evidence of the effects of liquid discharges from the power station (activity concentrations of caesium-137, and other radionuclides, in sediments). However, gamma dose rates measured on the shoreline (where anglers fish) were difficult to distinguish from background dose rates in 2025 and were generally similar (where comparison could be made) to those in 2024. The predominant radionuclide in the dose assessment was caesium-137. The time trends of concentrations of caesium-137 in sediments and discharges are shown in Figure 4.22. A substantial decline in concentrations was observed in the mid to late 1990s in line with reducing discharges. Since 2000, the discharges of caesium-137 have generally decreased, but with some variability. Concentrations have since decreased broadly, with fluctuations due to environmental variability and short periods of increased discharges, particularly in 2012 and 2013.

Figure 4.22. Caesium-137 liquid discharge, in GBq y^-1, from Trawsfynydd and concentration in sediment, in Bq kg^-1 (dry), in Trawsfynydd Lake, 1996 to 2025.

4.3.2. Wylfa, Isle of Anglesey

Wylfa Power Station is located on the north coast of Anglesey and has 2 Magnox reactors. It was the last and largest power station of its type to be built in the UK and commenced electricity generation in 1971 and ceased in 2015. Defuelling operations were completed in 2019 (Nuclear Decommissioning Authority 2020). This milestone marked the end of defuelling operations at all the UK’s first-generation nuclear reactors. In 2025, the UK Government announced the site will host a new power station to contain the UK’s first fleet of small modular reactors. In April 2026, Rolls-Royce SMR Ltd was contracted by Great British Energy – Nuclear (GBE-N) to design and deliver initially three SMR units, this project is named Gwyndod.

The most recent habits survey was undertaken in 2023 (Greenhill and others, 2024).

4.3.2.1. Doses to the public

The ‘total dose’ from all pathways and sources of radiation was 0.006mSv in 2025 (Table 4.1), which was less than 1% of the dose limit to members of the public. This is a decrease from 0.008mSv in 2024 because of a lower estimate of direct radiation compared with 2024. The representative person in 2025 was an adult eating marine plants and algae and was unchanged from 2024. The trend in ‘total dose’ over the period 2014 to 2025 is given in Figure 4.23. The annual ‘total dose’ has remained broadly similar, from year to year, and were generally very low.

Figure 4.23. ‘Total dose’, in mSv y^-1, at Wylfa nuclear power station, 2014 to 2025. (Small doses less than or equal to 0.005mSv are recorded as being 0.005mSv).

Year	Dose, mSv y-1
10% of the Dose limit	0.10
2014	0.007
2015	0.013
2016	0.008
2017	0.005
2018	0.006
2019	0.005
2020	0.006
2021	0.005
2022	0.014
2023	0.005
2024	0.008
2025	0.006

As in recent years, source-specific assessments for a high-rate consumer of locally grown foods, and for a high-rate consumer of fish and shellfish (including external radiation) gave exposure levels that were lower than the ‘total dose’ (Table 4.1). The dose to a high-rate consumer of fish and shellfish (including external radiation) was less than 0.005mSv in 2025 and unchanged from recent years. The dose to a high-rate consumer of locally grown foods was also less than 0.005mSv in 2025 and unchanged from recent years.

4.3.2.2. Gaseous discharges and terrestrial monitoring

The focus of the terrestrial sampling was for the analyses of tritium, carbon-14 and sulphur-35 in milk and crops. Data for 2025 are given in Table 4.13(a). As in recent years, sulphur-35 was not positively detected in milk, but was detected in grass and carbon-14 concentrations measured in locally produced milk were just above background levels in 2025.

4.3.2.3. Liquid waste discharges and aquatic monitoring

The aquatic monitoring programme consists of sampling of fish and shellfish, and the measurement of gamma dose rates. Samples of sediment, seawater and seaweed are analysed as environmental indicator materials. The results of the programme in 2025 are given in Table 4.13(a) and Table 4.13(b). The data for artificial radionuclides related to the Irish Sea continue to reflect the distant effects of Sellafield discharges. The activity concentrations in 2025 were similar to those in previous years. The reported concentration of technetium-99 in seaweed in 2025 (due to the distant effects of discharges to sea from Sellafield) was slightly higher than the level observed in 2024. Caesium-137 concentrations in sediment have remained low over the last decade (Figure 4.24). Overall, gamma dose rates in 2025 were generally similar to those measured in recent years.

Figure 4.24. Caesium-137 concentration, in Bq kg^-1 (dry), in marine sediments near Wylfa nuclear power station between 2014 and 2025.

Year	137Cs concentration Bq Kg-1 (dry)
2014	3.4
2015	2.7
2016	2.6
2017	3.0
2018	2.6
2019	2.6
2020	2.2
2021	2.1
2022	3.0
2023	2.7
2024	5.8
2025	2.1

5. Research and radiochemical production establishments

Highlights

• For research establishments assessed in 2025 the ‘total dose’ for the representative person was 1% (or less) of the annual dose limit

• For the radiochemical production establishment assessed in 2025 the ‘total dose’ for the representative person was 8% of the annual dose limit

Dounreay, Highland

• ‘total dose’ for the representative person was 0.008mSv and decreased in 2025 compared to 2024

Grove Centre, Amersham, Buckinghamshire

• ‘total dose’ for the representative person was 0.083mSv and decreased in 2025 compared to 2024

Harwell, Oxfordshire

• ‘total dose’ for the representative person was 0.007mSv and decreased in 2025 compared to 2024

Winfrith, Dorset

• ‘total dose’ for the representative person was less than 0.005mSv and decreased in 2025 compared to 2024

---

This section considers the results of monitoring near research establishments (Dounreay, Harwell, Winfrith and the former fusion energy research site at Culham) and 1 radiochemical production establishment (Grove Centre, Amersham).

In 2025, gaseous and liquid discharges were below regulated limits for each of the establishments (see Appendix 1, Table A1.1 and Table A1.2). Solid waste transfers in 2025 from NRS Dounreay are given in Appendix 1 (Table A1.4). Data tables and the detailed results of the dose assessments, in Open Document Spreadsheet (ODS) format, are downloadable from the main RIFE page.

5.1 Dounreay, Highland

The Dounreay site was opened in 1955 to develop research reactors. Three reactors were built on the site: the Prototype Fast Reactor, the Dounreay Fast Reactor, and the Dounreay Materials Test Reactor. All 3 reactors are now shut down and undergoing decommissioning.

The existing radioactive waste disposal authorisations were transferred to Dounreay Site Restoration Limited (DSRL), a new site licence company who took over the site management contract. DSRL became wholly owned by the NDA on 1 April 2021.

In 2025, radioactive waste discharges from the Dounreay site were made by NRS under an EASR radioactive substances authorisation granted by SEPA.

The quantities of both gaseous and liquid discharges were generally similar to those released in recent years (Appendix 1, Table A1.1 and Table A1.2). Solid waste transfers from Dounreay in 2025 are also given in Appendix 1 (Table A1.4).

The most recent habits survey was conducted in 2025. This habits survey did not identify any occupancy in the area of Oigin’s Geo (see Figure 5.2) that would form an external exposure pathway. The most recent habits survey is available on SEPA’s website:SEPA Habits surveys or can be requested by emailing RSEnquiries@sepa.org.uk.

In 2013, SEPA granted an authorisation to DSRL for the Low-Level Radioactive Waste Disposal Facility (LLWF) that is located adjacent to the main Dounreay site. The first phase of the disposal site comprised the construction and operation of 2 concrete vaults that began accepting low level radioactive waste and demolition low level waste from the Dounreay site in 2015. The safety case and planning permission allow for the construction of an additional 24 vaults at the site. Further phases of construction will be dependent on the progress with the decommissioning of the Dounreay site.

There are no authorised routes for liquid or gaseous discharges from the Dounreay LLWF. The facility is designed to contain the radioactive waste over a long time, allowing radioactive decay to occur while the waste remains isolated from the environment.

In June 2024, NRS notified SEPA of possible loss of radioactively contaminated water to the ground from the Carbon Bed Filter structure located within the Fuel Cycle Area. NRS’s investigation concluded that there was a small leak from the Carbon Bed Filter. NRS has subsequently removed water from the structure and installed level monitoring instrumentation. In July 2025, SEPA issued a regulatory notice requiring NRS to:

• undertake a review of existing groundwater monitoring arrangements
• assess compliance with the requirement to dispose of radioactive waste via an authorised route
• undertake characterisation to establish the extent of the radioactive contamination and develop a programme for undertaking the appropriate remediation

In August 2024, NRS notified SEPA that very low levels of radioactivity had been identified in samples taken from a sump collecting water ingress within a non-radioactive facility on the Dounreay site. The arrangements in place at the time involved the water being pumped from the sump and discharged to the marine environment via the non-active drainage system, which is not an authorised route for the disposal of liquid radioactive waste. Dounreay subsequently rerouted the discharge from the sump to the Low Active Drain shortly thereafter. SEPA’s investigation concluded that NRS had contravened conditions of its EASR radioactive substances authorisation. In October 2025, SEPA issued a Regulatory Notice requiring NRS to undertake a review of the management arrangements in place for the disposal of aqueous liquid waste.

5.1.1. Doses to the public

The ‘total dose’ from all pathways and sources of radiation was 0.008mSv in 2025 (Table 5.1), or less than 1% of the dose limit to members of the public. This is a decrease from 0.021mSv in 2024. The representative person was an adult living near the site and represents a change from 2024 (adult consuming game meat at high rates in 2024). The decrease in ‘total dose’ was mostly due to the change of habits (no game meat consumption) in 2025.

The trend in the annual ‘total dose’ over the period 2014 to 2025 is given in

Figure 5.1. Between 2014 to 2015, the change in annual ‘total dose’ was mostly due to the contribution of goats’ milk not being included in the assessment (which had been assessed prior to 2013), as milk samples have not been available in more recent years. In 2016, 2018, 2021, 2023 and 2024, the most significant contributor that influenced the dose was the concentration of caesium-137 found in venison (game).

Figure 5.1. ‘Total dose’, in mSv y^-1, at Dounreay, 2014 to 2025.

Year	Dose, mSv y-1
20% of the Dose limit	0.20
2014	0.012
2015	0.010
2016	0.058
2017	0.010
2018	0.035
2019	0.010
2020	0.009
2021	0.026
2022	0.010
2023	0.028
2024	0.021
2025	0.008

The annual dose to a consumer of terrestrial foodstuffs was 0.013mSv in 2025, or approximately 1% of the dose limit for members of the public of 1mSv, and down from 0.015mSv in 2024. As in previous years, adults were identified as the most exposed age group with reason for the decrease in dose was the reduction of caesium-137 in venison (24Bq kg^-1 in 2024 to 18Bq kg^-1 in 2025). The annual dose to a consumer of fish and shellfish, including external exposure from occupancy over local beaches, was lower than the ‘total dose’ in 2025 (0.008mSv) and was unchanged from 2024. As in recent years, the dose (external pathways only) to members of the public visiting Oigin’s Geo, based on previously collected habits data (Papworth, Garrod & Clyne 2014) and 2019 monitoring data, was less than 0.005mSv in 2025. The sample species, type and locations are listed in the respective site tables.

Figure 5.2. Monitoring locations at Dounreay, 2025 (not including farms or air sampling locations). The rectangle around the Dounreay site is presented inset.

5.1.2 Gaseous discharges and terrestrial monitoring

In 2025, NRS was authorised by SEPA to discharge radioactive gaseous wastes to the local environment via stacks to the atmosphere. The discharges also include a minor contribution from the adjoining reactor site (Vulcan Naval Reactor Test Establishment (NRTE)), which is operated by the MOD‘s Submarine Delivery Agency. Monitoring conducted in 2025 included the sampling of air, freshwater, grass, soil and locally grown terrestrial foods including meat and vegetables as well as wild foods. As there are no dairy cattle herds in the Dounreay area, no milk samples were collected from cattle. As in recent years, goats’ milk samples were not sampled, as no milk sample was available in 2025.

The sampling locations for the terrestrial (and marine) monitoring programmes shown in Figure 5.2. Figure 5.3 to Figure 5.7 provides time trends of radionuclide discharges (gaseous and liquid), which are generally decreasing over the period 2014 to 2025. The sample species, type and locations are listed in the respective site tables. The results for terrestrial samples and radioactivity in air are given in Table 5.2(a) and Table 5.2(c).

Figure 5.3. Discharges of gaseous iodine-129, in MBq y^-1, 2014 to 2025.

Year	Iodine-129 discharge, MBq y-1
2014	21
2015	30
2016	23
2017	17
2018	14
2019	14
2020	16
2021	13
2022	16
2023	15
2024	13
2025	12

Figure 5.4. Discharges of gaseous alpha, in MBq y^-1, 2014 to 2025.

Year	Alpha discharge, MBq y-1
2014	9.2
2015	8
2016	6.9
2017	6.5
2018	0.097
2019	0.11
2020	0.065
2021	0.068
2022	0.064
2023	0.083
2024	0.063
2025	0.07

Figure 5.5. Liquid discharges of strontium-90, in GBq y^-1, 2014 to 2025.

Year	Strontium-90 discharges ,GBq y-1
2014	28
2015	23
2016	24
2017	29
2018	39
2019	52
2020	48
2021	48
2022	46
2023	45
2024	40
2025	41

Figure 5.6. Liquid discharges of caesium-137, in GBq y^-1, 2014 to 2025.

Year	Caesium-137 discharges ,GBq y-1
2014	28
2015	23
2016	24
2017	29
2018	39
2019	52
2020	48
2021	48
2022	46
2023	45
2024	40
2025	41

Figure 5.7. Liquid discharges of alpha, in GBq y^-1, 2014 to 2025.

Year	Alpha discharges ,GBq y-1
2014	28
2015	23
2016	24
2017	29
2018	39
2019	52
2020	48
2021	48
2022	46
2023	45
2024	40
2025	41

Figure 5.8. Concentrations of technetium-99 in seaweed at Sandside Bay and Burwick Pier, Bq kg^-1 (fresh), 2014 to 2025.

Figure 5.9. Concentrations of caesium-137 in sediments at Sandside Bay and Rennibister, Bq kg^-1 (dry), 2014 to 2025.

The concentrations of radionuclides at Dounreay were generally low and relatively similar to those observed in previous years. As in recent years, strontium-90 was positively detected in a few food samples, and iodine-129 concentrations were all reported as ‘less than values’ in 2025. Activity concentrations in air samples at locations near to the site (Table 5.2(c)) were reported as ‘less than values’, apart from gross alpha (just above the Limit of Detection) from all three sampling locations.

Caesium-137 is likely to be present in terrestrial samples from the Dounreay area due to fallout from weapons testing in the 1960s and from the Chernobyl reactor accident in 1986. As in recent years, caesium-137 was positively detected in the venison sample collected in 2025 (18Bq kg^-1) and was slightly lower than that observed in 2024 (24Bq kg^-1). Unlike 2024, a honey sample was not available in 2025. Earlier RIFE reports have provided results and interpretation of honey monitoring (for example Environment Agency and others, 2018).

5.1.3 Liquid waste discharges and aquatic monitoring

Low level liquid waste is routed via a Low-Level Liquid Effluent Treatment Plant (LLLETP). The effluent is discharged to sea (Pentland Firth) via a pipeline terminating 600 metres offshore at a depth of about 24 metres. The discharges also include groundwater pumped from the Dounreay shaft, surface water runoff, leachate from the on-site low level solid waste disposal facility (which operated from 1958 to 2005), and a minor contribution from the adjoining reactor site (Vulcan NRTE).

Routine marine monitoring included sampling of seafood and the measurement of beta and gamma dose rates. A Food and Environment Protection Act (FEPA) Order^{[footnote 10]} exists which prevents the collection of seafood within a defined area around the long sea outfall. Samples can be collected under consent granted in 1997 by the Scottish Office and revised in 2011 by the FSS (then FSA in Scotland).

Cod, crab, mussel and winkle samples were collected from areas along the Caithness coastline. Additionally, sediment, seawater and seaweed were sampled in 2025 as indicator materials. The results for marine samples, and gamma and beta dose rates, are given in Table 5.2(a) and Table 5.2(b). Activity concentrations were generally low in 2025 and similar to those in recent years. Technetium-99 concentrations in seaweed remained at the levels expected for this distance from Sellafield and were lower to those reported in previous years (Figure 3.21). Figure 5.8 also gives time trend information for technetium-99 concentrations (from Sellafield) in seaweed at Sandside Bay (location shown in Figure 5.2), and Burwick. Data indicate a general decline in concentrations over the period at both locations. Caesium-137 concentrations in sediment (Figure 5.9) at Sandside Bay and Rennibister (both 2014 to 2025), have generally decreased albeit with fluctuations due to environmental variability. Overall, gamma dose rates in 2025 were slightly higher than those observed in recent years. As in recent years, beta dose rate measurements were all reported as ‘less than values’ (Table 5.2(b)) in 2025.

During 2025, NRS continued monitoring of local public beaches, using vehicle mounted detectors, for radioactive fragments in compliance with the requirements of the authorisation granted by SEPA. In 2025, 4 fragments were recovered from Sandside Bay, and 3 fragments were recovered from the Dounreay foreshore. The caesium-137 activity measured in the fragments recovered from Sandside Bay ranged from 9.2kBq to 120kBq. Fragments recovered from the Dounreay foreshore ranged from 29kBq to 1400kBq.

Dounreay particle updates are posted on Radioactive particles in the environment around Dounreay - GOV.UK (www.gov.uk)(onshore monitoring of radioactive particles) and pre-2023, particle find updates can be found here Radioactive particles in the environment around Dounreay - Pre-2023 Data Only and from October 2023 onwards particle find updates can be found here (onshore monitoring of radioactive particles

The previously conducted offshore survey work provided data on repopulation rates of particles (fragments) to areas of the seabed previously cleared of particles. This work has improved the understanding of particle movements in the marine environment. The Dounreay Particles Advisory Group (DPAG) completed its work following the production of its Fourth Report (Dounreay Particles Advisory Group 2008). Since the work of Dounreay Particles Advisory Group^{[footnote 11]} was concluded, Particles Retrieval Advisory Group (Dounreay) (PRAG(D)) has published reports in 2010, 2011, 2016 and 2026 (Particles Retrieval Advisory Group (Dounreay) 2010; Particles Retrieval Advisory Group (Dounreay) 2011; Particles Retrieval Advisory Group (Dounreay) 2016; Particles Retrieval Advisory Group (Dounreay) 2026). In 2026, the Particles Retrieval Advisory Group (Dounreay) (PRAG(D)) published its 2025 report. This publication provides an overview of the health risks from fragments generated at Dounreay; consideration of movement of fragments in the offshore environment; reviewing the numbers of fragments found through the beach monitoring programme and outlines potential numbers of fragments remaining in the environment. Additionally, the report outlines support to maintain the Food and Environment Protection Act Order, ongoing monitoring and sets out concerns in relation to plans to install high-voltage cables in the Dounreay offshore environment (Particles Retrieval Advisory Group (Dounreay) 2026).

The Particles Retrieval Advisory Group (Dounreay) (PRAG(D)) have published a report in September 2026.

In 2007, the FSA reviewed the Dounreay FEPA Order. A risk assessment, that was peer-reviewed by UKHSA, indicated that the food chain risk was very small (Food Standards Agency 2009). The FEPA Order was reviewed with regard to ongoing work to remove radioactive particles from the seabed and the food chain risk. In 2009, the FSA in Scotland (now FSS) announced that the FEPA Order would remain in place and be reviewed again upon completion of the (now completed) seabed remediation work. Following a recommendation in the 2016 PRAG(D) report, FSS agreed that the FEPA Order would remain in place and be reviewed following re-evaluation of particle arrival rates. The 2025 PRAG(D) report reviewed the impact of offshore retrievals on particle arrival rates at local beaches.  The report recommended that the current monitoring programme should continue and that the offshore FEPA area should not be disturbed.

The FEPA Order prevents disturbance of the area in relation to seafood harvesting; however, it cannot prevent any sediment movement by natural processes or by high voltage power cables being placed in the area to transfer energy to the National Grid. SEPA is aware of a number of propositions in the Dounreay offshore area to lay energy cables that could result in the disturbance of sediment. SEPA is engaging with those involved in offshore cable laying to assess the potential impacts on the offshore environment.

5.2. Grove Centre, Amersham, Buckinghamshire

The Grove Centre is operated by GE Healthcare Limited, it consists of a range of plants previously used for manufacturing diagnostic imaging products for use in medicine and research, which are now closed and being decommissioned. In April 2026, the ONR relicensed GE Healthcare Limited’s nuclear licensed site after the site footprint was reduced by a half as part of major remediation activities.

The monitoring programme consists of analysis of fish, crops, water, soil and other environmental materials, and measurements of gamma dose rates. The monitoring locations are shown in Figure 5.10. The sample species, type and locations are listed in the respective site tables. The most recent habits survey was undertaken in 2016 (Clyne and others, 2017).

Figure 5.10. Monitoring locations near the River Thames, 2025 (not including farms).

5.2.1. Doses to the public

The ‘total dose’ from all pathways and sources of radiation was estimated to be 0.083mSv in 2025 (Table 5.1) or less than 9% of the dose limit to members of the public. This was a decrease from 2024 (0.087mSv). As in recent years, the dominant contribution to ‘total dose’ was from direct radiation from stored radioactive waste. The representative person was a prenatal child of an adult living in the vicinity of the site in 2025 (unchanged from 2024). Exposure from direct radiation varies around the boundary of the Grove Centre and therefore the ‘total dose’ is estimated as a cautious upper value. The trend in annual ‘total dose’ over the period 2014 to 2025 is given in Figure 5.11. The lower values are due to all distribution activities ceasing in 2019. Dose from the site has since been dominated by radiation from the waste store. The ‘total dose’ is expected to be no more than the conservative estimated value of 0.083mSv. The trends in ‘total dose’ is given in Figure 5.11. The doses are dominated by direct radiation, estimates of which have remained relatively constant in the recent years.

Figure 5.11. ‘Total dose’, in mSv y^-1, at the Grove Centre, Amersham, 2014 to 2025.

Year	Dose, mSv y-1
20% of the Dose limit	0.20
2014	0.14
2015	0.14
2016	0.15
2017	0.15
2018	0.14
2019	0.14
2020	0.14
2021	0.083
2022	0.086
2023	0.089
2024	0.087
2025	0.083

As in recent years, source-specific assessments for a high-rate consumer of locally grown foods, for an angler and for a worker at Maple Lodge Sewage Treatment Works (STW), which serves the sewers to which permitted discharges are made, gave exposures that were less than the ‘total dose’ in 2025 (Table 5.1). The dose for a high-rate consumer of locally grown foods was less than 0.005mSv in 2025 and down from 2024 (0.010mSv). This decrease in dose was mostly due to a lower contribution from the gaseous discharges of radon-222 in 2025. It should be noted that the current assessment methodology uses a conservative dose factor based on this nuclide being in equilibrium with its decay products. In 2025 the dose to a local angler was 0.005mSv and slightly up from recent years (reported as less than 0.005mSv in 2024 and 2023).

The 2016 habits survey at Amersham did not directly identify any consumers of fish, shellfish or freshwater plants. As in previous surveys, however, there were reports of occasional coarse fish and signal crayfish consumption (but no actual consumption rates). To allow for this, a consumption rate of 1kg per year for fish and signal crayfish has been included in the dose assessment for an angler.

The Grove Centre discharges liquid waste to Maple Lodge STW, and the proximity to raw sewage and sludge experienced by sewage treatment workers is a likely exposure pathway (National Dose Assessment Working Group 2004). The dose received by one of these workers was modelled using the methods described in Appendix 3. The dose from a combination of external exposure to contaminated raw sewage and sludge, inadvertent ingestion and inhalation of re-suspended radionuclides was less than 0.005mSv in 2025 and unchanged from recent years.

5.2.2 Gaseous discharges and terrestrial monitoring

The Grove Centre is permitted to discharge gaseous radioactive wastes via stacks on the site. Gaseous discharges of radon-222 decreased in 2025, in comparison with those in 2024. The radon-222 discharges are associated with retrieval and repackaging of legacy radium waste. These retrievals are now nearly complete, resulting in a much-reduced radon-222 discharges since April 2025. The results for the terrestrial monitoring for 2025 are given in Table 5.3(a) and Table 5.3(b). As in recent years, caesium-137 deposited from atmospheric fallout was detected in soil near the site in 2025.

5.2.3 Liquid waste discharges and aquatic monitoring

Radioactive liquid wastes are discharged to sewers serving the Maple Lodge STW; treated effluent subsequently enters the Grand Union Canal and the River Colne. The results of the aquatic monitoring programme for 2025 are given in Table 5.3(a). As in recent years, activity concentrations of tritium, iodine-131 (believed to originate from the therapeutic use of this radionuclide in local hospitals) and caesium-137 in freshwater were all reported as ‘less than values’ in 2025. Samples of effluent and sludge from Maple Lodge STW were also collected in 2025. The concentration levels observed in these samples were similar to the latest results observed in recent years and iodine-131 (likely from therapeutic use in hospitals) was positively detected in the crude effluent and the digested sludge collected in 2025.Tritium, gross alpha and gross beta concentrations observed in freshwater were below the investigation levels for drinking water in the Water Supply (Water Quality) (Amendment) 2018 Regulations (retained from the European Directive 2013/51). Gamma dose rates over grass were generally indistinguishable from natural background in 2025 (Table 5.3(b)) and were broadly similar to those measured in recent years.

5.3. Harwell, Oxfordshire

The Harwell site was established in 1946 as the UK’s first Atomic Energy Research Establishment and is situated approximately 5km southwest of the town of Didcot. Since 2015, the Harwell site has been operated by NRS on behalf of the NDA. The Harwell nuclear site forms part of Harwell Campus, a science, innovation and business campus. The site accommodated 5 research reactors of various types. Harwell also had a number of other nuclear research facilities, together with plutonium handling facilities, radioactive laboratories, nuclear waste treatment and storage facilities.

Decommissioning at Harwell is well underway. Two research reactors have been completely removed, and the fuel has been removed from the remaining 3 which are now in decommissioning. Several facilities have now been removed from the site and others are being decommissioned. Historic wastes are being retrieved from their existing storage locations and repackaged for longer-term storage and eventual disposal.

In 2022, the final remediation work was completed for the decommissioned Liquid Effluent Treatment Plant. Radiological sampling to support the environmental permit surrender and delicensing of this area is now complete. Once the area is released from radioactive substances regulation, this land will be handed back to the Harwell Science Park for future development.

The most recent habits survey was conducted in 2015 (Clyne, Garrod & Dewar 2016).

5.3.1. Doses to the public

The ‘total dose’ from all pathways and sources of radiation was 0.007mSv in 2025 (Table 5.1), which was less than 1% of the dose limit to members of the public and similar to that in 2024 (0.008mSv). The decrease in dose was mainly related to the exclusion of the direct radiation from the site, which could not be distinguished from elevated levels unrelated to the site (Table 1.1). The representative person was an adult spending time over sediments. This is a change from 2024 (adult living near the site). The trend in annual ‘total dose’ over the period 2014 to 2025 is given in Figure 5.12. The ‘total dose’ was broadly similar, between 2014 and 2016, and was low. The increase in ‘total dose’ in 2017, and then decrease in 2018, were attributed to changes in the estimate of direct radiation from the site.

Figure 5.12. ‘Total dose’, in mSv y^-1, at Harwell, 2014 to 2025. (Small doses less than or equal to 0.005mSv are recorded as being 0.005mSv).

Year	Dose, mSv y-1
20% of the Dose limit	0.20
2014	0.016
2015	0.017
2016	0.015
2017	0.046
2018	0.028
2019	0.010
2020	0.008
2021	0.005
2022	0.005
2023	0.005
2024	0.008
2025	0.007

As in recent years, the source-specific assessment for a high-rate consumer of terrestrial foods gave an exposure that was less than 0.005mSv in 2025 (Table 5.1). The source-specific assessment for an angler gave an exposure of 0.007mSv in 2025 and increased from less than 0.005mSv in 2024. The increase in dose was mostly attributed to a higher gamma dose rate measured over grass at Sutton Courtney.

5.3.2 Gaseous discharges and terrestrial monitoring

Gaseous wastes are discharged via stacks to the local environment. As in previous years, discharges of radioactive wastes continued at very low rates. The terrestrial monitoring programme sampled milk, fruit and cereal. The results of the terrestrial monitoring programme in 2025 are shown in Table 5.4. As in recent years, tritium concentrations in terrestrial samples were all reported as ‘less than’ values in 2025.

5.3.3 Liquid waste discharges and aquatic monitoring

Permitted liquid discharges from Harwell are discharged to sewers serving the Didcot STW; treated effluent subsequently enters the River Thames at Long Wittenham.

Permitted discharges of surface water drainage from the Harwell site are made via the Lydebank Brook. As in recent years, discharges to Lydebank Brook were very low. The liquid discharges of alpha-emitting radionuclides and tritium decreased in 2025, in comparison to those in 2024, due to lower volume of effluents via this route due to lower rainfall. Figure 5.13 shows trends of discharges over time (2014 to 2025) for cobalt-60 and caesium-137 to sewer. There was an overall reduction in the discharges over the whole period and very low discharges in most recent years.

Figure 5.13(a). Trends in liquid discharges, to sewer, of cobalt-60, in MBq y^-1, from Harwell, Oxfordshire 2014 to 2025.

Year	60Co discharge, MBq y-1
2014	1.6
2015	1.0
2016	0.039
2017	0.29
2018	0.23
2019	0.45
2020	0.15
2021	0.25
2022	0.22
2023	0.13
2024	0.13
2025	0.17

Figure 5.13(b). Trends in liquid discharges, to sewer, of caesium-137, in MBq y^-1, from Harwell, Oxfordshire 2014 to 2025.

Year	137Cs discharge, MBq y-1
2014	35
2015	7.7
2016	0.11
2017	2.7
2018	3.6
2019	3.6
2020	0.24
2021	0.17
2022	0.13
2023	0.10
2024	0.15
2025	0.16

The aquatic monitoring programme is directed at consumers of fish and occupancy (sediment and freshwater samples) close to the liquid discharge point. Due to on-going access issues at Day’s Lock, the Environment Agency have replaced this sampling location with River Thames above Shillingford. The results of the aquatic monitoring programme in 2025 are shown in Table 5.4. As in recent years, concentrations of tritium, cobalt-60 and caesium-137 in freshwater were reported as ‘less than values’ in 2025. The caesium-137 concentration in sediment continued to be slightly enhanced above background levels in 2025. As in 2024, plutonium-239+240 were positively detected at low levels in the sediment collected near Sutton Courtenay in 2025.

5.4. Winfrith, Dorset

The Winfrith site is located near Winfrith Newburgh, Dorset. It was established in 1957 as an experimental reactor research and development site. Since 2015, the Winfrith site has been operated by NRS on behalf of the NDA. At various times, there have been 9 research and development reactors. The last operational reactor at Winfrith closed in 1995. Seven of the reactors have been decommissioned. The final 2; the Steam Generating Heavy Water and ‘Dragon’ (high temperature gas-cooled) reactors and supporting site facilities, are in the process of being decommissioned. It is the end state intention of NRS to return most of the land to a brownfield heathland site with public access.

NRS Winfrith is located adjacent to the Tradebe-Inutec site. Tradebe-Inutec is an independent nuclear operator (see section 7.3). NRS Winfrith and Tradebe-Inutec undertake separate site environmental monitoring programmes as required by their respective environmental permits. However, in this report, NRS Winfrith and Tradebe-Inutec are considered together for the purposes of environmental monitoring because, with the exclusion of their liquid discharges (which discharge to different geographic areas), their operational activities and gaseous discharges impact on the same local area.

The most recent habits survey (covering both the NRS and Tradebe-Inutec sites) was conducted in 2019 (Moore, Clyne & Greenhill 2020).

5.4.1. Doses to the public

In 2025, the ‘total dose’ from all pathways and sources of radiation was less than 0.005mSv (Table 5.1), or less than 0.5% of the dose limit to members of the public. This is a decrease from 0.015mSv in 2024. The decrease in dose was mainly related to the exclusion of the direct radiation from the site, as the dose rates measured were found to originate from other sources or measurement errors and were not attributable to the site (Table 1.1). The representative person was an adult spending time over sediments. This is a change from 2024 (adult living near the site). Trends in annual ‘total dose’ over the period between 2014 and 2025 are shown in Figure 5.14. In 2014, ‘total dose’ was very low. The variations observed since 2015 are mainly due to changes in the estimates of direct radiation from the site. The fluctuations in estimates of total dose at NRS Winfrith has been attributed to the extent of the decommissioning work undertaken at the site in the recent years, including removal, temporary storage, and transfer of legacy wastes for off-site disposal. The specific waste transfer activities that occurred in recent years, were time limited in nature, and form part of the routine operational work required to secure the safe decommissioning of the site. Estimates of ‘total dose’ will fluctuate with operational decommissioning work demands as the site proceeds through to the final stage of decommissioning and all radioactive waste management activities cease.

Figure 5.14. ‘Total dose’, in mSv y^-1, at Winfrith, 2014 to 2025. (Small doses less than or equal to 0.005mSv are recorded as being 0.005mSv).

Year	Dose, mSv y-1
20% of the Dose limit	0.20
2014	0.005
2015	0.014
2016	0.019
2017	0.038
2018	0.027
2019	0.027
2020	0.014
2021	0.006
2022	0.028
2023	0.054
2024	0.015
2025	0.005

As in 2024, the doses to a high-rate consumer of locally grown food and of fish and shellfish, were less than 0.005mSv in 2025.

5.4.2 Gaseous discharges and terrestrial monitoring

At NRS Winfrith, gaseous radioactive waste is discharged via various stacks to the local environment. As in previous years, discharges were very low in 2025. In this report, gaseous discharges from NRS Winfrith and Tradebe-Inutec are considered together for the purposes of environmental monitoring because their operational activities and gaseous discharges impact on the same local area.

The focus of the terrestrial sampling was the analyses of tritium and carbon-14 in milk and crops. Local freshwater, grass and sediment samples were also analysed. Sampling locations at Winfrith are shown in Figure 5.15. The sample species, type and locations are listed in the respective site tables. Data for 2025 are given in Table 5.5(a). Results from terrestrial samples provide little indication of an effect due to gaseous discharges. As in recent years, the carbon-14 concentrations in locally produced milk were above values used to represent background concentrations. Unlike in 2024, tritium was positively detected in surface waters in 2025 (North of site and River Win east of site). Tritium, gross alpha, and gross beta concentrations in freshwater were below the investigation levels for drinking water in the Water Supply (Water Quality) (Amendment) 2018 Regulations (retained from the European Directive 2013/51).

Figure 5.15. Monitoring locations at Winfrith, 2025 (not including farms).

5.4.3 Liquid waste discharges and aquatic monitoring

Liquid wastes, from the NRS Winfrith site, are disposed via a pipeline to deep water in Weymouth Bay. As in previous years, discharges continued at very low rates in 2025 (all reported as <1% of the annual limit).

Figure 5.16 shows trends of liquid discharges over time (2014 to 2025) for tritium and alpha-emitting radionuclides. In recent years, discharges of alpha-emitting radionuclides have remained very low. In comparison, tritium discharges have varied more between years, with periodic peaks in releases, due to operations at Tradebe-Inutec, but have also generally declined since 2015 and ceased in 2019.

Figure 5.16(a). Trends in liquid discharges of tritium, in TBq y^-1, from NRS Winfrith, 2014 to 2025.

Year	Tritium discharge, TBq y-1
2014	1.0
2015	11
2016	7.1
2017	1.0
2018	1.9
2019	0.00063
2020	0.028
2021	0.0008
2022	0.00036
2023	0.00022
2024	0.00056
2025	0.00026

Figure 5.16(b). Trends in liquid discharges of alpha emitting radionuclides, in MBq y^-1, from NRS Winfrith, 2014 to 2025.

Year	Alpha discharge, MBq y-1
2014	11
2015	4.3
2016	4.7
2017	7.6
2018	4.0
2019	1.0
2020	0.81
2021	0.76
2022	0.53
2023	0.50
2024	0.55
2025	0.37

Analyses of seafood and marine indicator materials and measurements of external radiation over muddy intertidal areas were conducted in 2025. These are primarily to determine the effects of liquid discharges from the NRS Winfrith site and, to a lesser extent, historical (pre-2019) liquid discharges from Tradebe-Inutec. The results of the aquatic monitoring programme and measurements of external radiation in 2025 are shown in Table 5.5(a) and Table 5.5 (b) respectively. Concentrations of radionuclides in the marine environment were low and similar to those in previous years. Unlike in 2024, technetium-99 was positively detected in seaweed samples collected at Bognor Rocks, but caesium-137 was not positively detected in the fish sample collected from Weymouth Bay (skates and rays). Gamma dose rates in 2025 were generally similar to those measured in 2024 (where comparison could be made).

5.5. Culham, Oxfordshire

Culham Centre for Fusion Energy, operated by the United Kingdom Atomic Energy Authority (UKAEA), is the UK’s national laboratory for fusion research. The Culham Centre for Fusion Energy hosts and is responsible for the operation of 2 experimental fusion reactors: the Joint European Torus and the Mega Amp Spherical Tokamak (MAST) Upgrade. The Joint European Torus concluded its operation in 2023.

The Culham site also operates several other facilities to support fusion energy and related technologies and should host commercial fusion developers to become a fusion cluster hub in the future.

A site-specific ‘total dose’ has not determined at this site in this report because an integrated habits survey has not been undertaken. As in recent years, the source-specific dose (including tritium and caesium-137), from using the River Thames directly as a source of drinking water, downstream of the discharge point at Culham, was estimated to be less than 0.005mSv in 2025 (Table 5.1).

Monitoring of soil and grass around Culham and of sediment and water from the River Thames was undertaken in 2025. Locations and data are shown in Figure 5.10 and Table 5.6, respectively. Historically, the main effect of the site’s operation was the increased tritium concentrations found in grass collected near the site perimeter. As in recent years, concentrations of tritium in all samples were reported as ‘less than values’. The reported caesium-137 concentration in the downstream sediment collected in 2025 was 11Bq kg^-1 and was slightly lower in comparison with 2024 was lower 14Bq kg^-1). Caesium-137 concentrations in the River Thames sediment are not attributable to Culham but were most likely due to past discharges from Harwell and fallout from Chernobyl and nuclear weapons testing.

6. Defence establishments

Highlights

• For the defence establishments assessed in 2025 the ‘total dose’ for the representative person was 10% of the annual dose limit

Aldermaston and Burghfield, Berkshire

• ‘total dose’ for the representative person was 0.10mSv and increased in 2025 compared to 2024

Barrow, Cumbria

• ‘total dose’ for the representative person was 0.066mSv and increased in 2025 compared to 2024

Derby, Derbyshire

• ‘total dose’ for the representative person was 0.006mSv and was similar in 2025 to 2024

Devonport, Devon

• ‘total dose’ for the representative person was less than 0.005mSv and unchanged in 2025 compared to 2024

Faslane and Coulport, Argyll and Bute

• ‘total dose’ for the representative person was 0.007mSv and increased in 2025 compared to 2024

Rosyth, Fife

• ‘total dose’ for the representative person was 0.007mSv and decreased in 2025 compared to 2024

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This section considers the results of monitoring undertaken by the Environment Agency, FSA, FSS and SEPA, near 8 defence-related establishments in the UK. In addition, the MOD undertakes monitoring at other defence sites where radiological contamination may occur. Data tables and the detailed results of the dose assessments, in Open Document Spreadsheet (ODS) format, are downloadable from the main RIFE page.

In 2025, gaseous and liquid discharges were below regulated limits for each of the defence establishments, see Appendix 1, Table A1.1 and Table A1.2. Solid waste transfers in 2025 from nuclear establishments in Scotland (Coulport, Faslane, Rosyth and Vulcan) are also given in Appendix 1 (Table A1.4).

6.1. Aldermaston and Burghfield

The Atomic Weapons Establishment (AWE) has 2 sites located in Berkshire: AWE Aldermaston and AWE Burghfield. AWE Aldermaston provides and maintains the fundamental components of the UK’s nuclear deterrent, including component manufacture and radioactive waste management activities. The day-to-day operations and the maintenance of the UK’s nuclear stockpile are managed, on behalf of the MOD, by AWE plc (which is a non-departmental public body, wholly owned by the MOD). AWE Burghfield is responsible for the final assembly and maintenance of warheads whilst in service, as well as their decommissioning. Gaseous and liquid discharges of radioactive waste to the environment are regulated by the Environment Agency, permitting discharges of low concentrations of radioactive waste.

The most recent habits survey to determine the consumption and occupancy rates by members of the public in the vicinity of the sites was undertaken in 2022 (Greenhill and others, 2023).

6.1.1. Doses to the public

In 2025, the ‘total dose’ from all pathways and sources of radiation was 0.10mSv (Table 6.1), or 10% of the dose limit to members of the public. This is an increase from 0.010mSv in 2024. This increase in the ‘total dose’ was primarily a result of a higher estimate of direct radiation from Aldermaston in 2025, which was driven by abnormally low background radiation measurements in the vicinity of the site rather than measurable increases in direct radiation from the site. This can arise from the inherent variability and measurement uncertainties associated with establishing background dose rates. As in recent years, the representative person was an adult consuming game meat at high rates.

Source-specific assessments for high-rate consumers of locally grown foods, for sewage workers, and for anglers gave exposures that were less than 0.005mSv in 2025 (Table 6.1), and these were consistent with the corresponding assessment results of recent years. Estimates of activity concentrations in fish, used for the dose determination, have been based on shellfish samples from the aquatic monitoring programme. A low consumption rate of 1kg per year for fish has been included in the dose assessment for anglers.

6.1.2 Gaseous discharges and terrestrial monitoring

Permitted discharges of gaseous radioactive waste are made via stacks from facilities at AWE Aldermaston and AWE Burghfield. Samples of milk, terrestrial foodstuffs, grass and soil were taken from locations close to the sites (Figure 5.10), and the results of the terrestrial monitoring in 2025 are given in Table 6.2(a). In 2025, tritium concentrations and other radionuclides in foodstuffs, including milk, were very low or reported as ‘less than values’. Caesium-137 concentrations were positively detected in soil samples and were generally similar to those measured in previous years. For all food samples, caesium-137 concentrations were reported as ‘less than values’ in 2025. Caesium-137 was positively detected in one of the four grass samples in 2025. Uranium isotopes in milk were not positively detected in 2025 as was the also case in 2024.

6.1.3 Liquid waste discharges and aquatic monitoring

Permitted discharges of radioactive liquid effluent are made to the sewage treatment works at Silchester (Figure 5.10), and to the Aldermaston Stream from AWE Aldermaston. A time-series trend of generally decreasing tritium discharges from AWE Aldermaston, over the period 2014 to 2025, is shown in Figure 6.1. Tritium discharges have declined more significantly, over a longer period in comparison to the last decade (Environment Agency and others, 2018). The longer-term decline in discharges is partly due to the reduction of historical groundwater contamination by radioactive decay and dilution by natural processes. Discharges of radioactive liquid effluent from AWE Burghfield are made to a sewage treatment works located on the site. Environmental monitoring of the River Thames, at Pangbourne and Mapledurham, has continued to assess the effect of historical discharges.

Figure 6.1. Trends in liquid discharges of tritium, in GBq y^-1, from Aldermaston, Berkshire 2014 to 2025 (including discharges to Silchester sewer and Aldermaston Stream).

Year	Tritium discharge, GBq -1
2014	0.67
2015	0.11
2016	0.45
2017	0.51
2018	0.38
2019	0.41
2020	0.30
2021	0.35
2022	0.26
2023	0.28
2024	0.26
2025	0.25

Activity concentrations for freshwater, fish, sediment samples, including gully pot sediments from road drains, and measurements of gamma dose rates, are given in Table 6.2(a) and Table 6.2(b). The concentrations of artificial radioactivity detected in the Thames catchment were very low in 2025 and generally similar to those in recent years. Activity concentrations of artificial radionuclides in shellfish were very low in 2025 and similar to those reported in recent years. The results from analyses of caesium-137 and uranium activity concentrations in River Kennet sediments were broadly consistent with those observed in recent years. As in 2025, tritium concentrations in freshwater samples were all reported as ‘less than values’, and caesium-137 concentrations in gully pot sediments were broadly similar to those measured in 2024. Gross alpha and beta activities in freshwater samples were below the investigation levels for drinking water in the Water Supply (Water Quality) (Amendment) 2018 Regulations (based upon the European Directive 2013/51). Gamma dose rates were below or close to natural background.

6.2. Barrow, Cumbria

At Barrow, BAE Systems Marine Limited builds, tests and commissions new nuclear-powered submarines. Gaseous discharges were reported as nil, and liquid discharges of tritium, carbon-14 and cobalt-60 to sewer were all below 1% of the annual limit in 2025. The most recent habits survey was undertaken in 2025 (Greenhill and others, 2026).

The ‘total dose’ from all pathways and sources of radiation was 0.066mSv (Table 6.1) in 2025, or less than 7% of the dose limit to members of the public. This is an increase from 0.061mSv in 2024. Most of this dose was due to the effects of Sellafield discharges. As in recent years, the representative person was an adult living on a local houseboat. The increase in ‘total dose’ was primarily due to an increase in the rate of houseboat occupancy. A secondary factor for the ‘total dose’ was a change in habits information: the most recent habits survey (Greenhill and others, 2026) noted that there was only a houseboat at Askam Pier. As the gamma dose rates at Askam Pier are typically lower than that at Roa Island, this negated some of the increase in ‘total dose’ that arose from the increase in houseboat occupancy rates. The trend in ‘total dose’ over the period 2014 to 2025 is given in Figure 6.2, ranging from 0.030 to 0.082mSv.

Figure 6.2. ‘Total dose’, in mSv y^-1, at Barrow (2014 to 2025). Doses are largely due to Sellafield discharges

Year	Dose, mSv y-1
10% of the Dose limit	0.10
2014	0.055
2015	0.051
2016	0.082
2017	0.074
2018	0.046
2019	0.057
2020	0.061
2021	0.044
2022	0.030
2023	0.042
2024	0.061
2025	0.066

As in 2024, source-specific assessments for a person living on a local houseboat gave exposures that were slightly lower than the ‘total dose’ in 2025 (Table 6.1). The assessment for a high-rate consumer of locally grown food (<0.005mSv) was unchanged from the 2024 value. No assessment of seafood consumption was undertaken in 2025 due to the absence of relevant monitoring data. However, the dose from seafood consumption is less important than that from external exposure on a houseboat (Environment Agency and others, 2014).

The FSA’s terrestrial monitoring at Barrow is limited to vegetable and grass (or silage) sampling. The Environment Agency monitors gamma dose rates and radioactivity concentrations in sediment samples from local intertidal areas and is directed primarily at the far-field effects of Sellafield discharges. The results are given in Table 6.3(a) and Table 6.3(b). No effects of discharges from Barrow were apparent in the concentrations of radioactivity in vegetables and grass, with most results reported at or below the limit of detection. The reported gross beta concentration, due to the far-field effects of Sellafield discharges, in Walney Channel sediment in 2025 was generally consistent with values measured in recent years. The gamma dose rates in intertidal areas near Barrow in 2025 are given in Table 6.3(b) and Table 3.9. Gamma dose rates measured in 2025 were also generally consistent with measurements from recent years. Gamma dose rates for the area are higher than the expected background levels, and this enhancement is most likely due to the far-field effects of historical discharges from Sellafield.

6.3. Derby, Derbyshire

Rolls-Royce Submarines Limited (RRSL) a subsidiary of Rolls-Royce plc, carries out design, development, testing and manufacture of reactor cores for nuclear-powered submarines at its 2 adjacent sites in Raynesway in Derby. Small discharges of liquid effluent are made via the Megaloughton Lane STW to the River Derwent and very low concentrations of alpha activity are present in releases to the atmosphere. Other wastes are disposed of by transfer to other sites, for example, at a permitted solid waste disposal site or by incineration. The most recent habits survey was undertaken in 2021 (Greenhill, Clyne & Moore 2022).

6.3.1. Doses to the public

The ‘total dose’ from all pathways and sources of radiation was 0.006mSv in 2025 (Table 6.1), which is less than 1% of the dose limit to members of the public. This is similar to the value reported in 2024 (0.007mSv). The representative person was a child living near the site in 2025 and was unchanged from 2024. Source-specific assessments for consumption of fish, crustaceans and drinking river water at high-rates, and for spending time over river-washed areas gave an exposure that was less than 0.005mSv in 2025. Similarly, a source-specific assessment for inhabitants of the area consuming locally grown vegetables gave an exposure estimate that was less than 0.005mSv in 2025 (Table 6.1).

Results of the routine monitoring programme at Derby are given in Table 6.3(a). Concentrations of uranium in samples taken around the site in 2025 were generally similar to those observed in previous years. More detailed analysis in previous years has shown the activity as being consistent with natural sources. The gross alpha and beta activities in water samples from the River Derwent were less than the investigation levels for drinking water in the Water Supply (Water Quality) (Amendment) 2018 Regulations (based upon the European Directive 2013/51). Caesium-137 detected in sediments from local water courses was most likely from historic fallout associated with overseas sources, such as nuclear weapons testing.

Table 6.3(a) also includes analytical results for a water sample taken from Fritchley Brook, downstream of Hilts Quarry, near Crich in Derbyshire. Rolls-Royce Submarines Limited formerly used the quarry for the controlled burial of solid low level radioactive waste. Concentrations of uranium isotopes detected in the sample in 2025 were broadly similar to those reported elsewhere in Derbyshire (Table 8.7).

6.4. Devonport, Devon

The Devonport Royal Dockyard consists of 2 parts and is operated by His Majesty’s Naval Base (HMNB) (owned and operated by the MOD) and Devonport Royal Dockyard Limited (owned by Babcock International Group plc). Devonport Royal Dockyard refits, defuels, refuels, repairs and maintains the Royal Navy’s nuclear-powered submarine fleet. Gaseous and liquid discharges of radioactive waste to the environment are regulated by the Environment Agency.

The most recent habits survey to determine the consumption and occupancy rates by members of the public was undertaken in 2017 (Moore and others, 2018). The routine monitoring programme in 2025 consisted of measurements of gamma dose rate and analysis of grass, vegetables, fish, shellfish and other environmental indicator materials (Table 6.3(a) and Table 6.3(b)).

6.4.1. Doses to the public

The ‘total dose’ from all pathways and sources of radiation was less than 0.005mSv in 2025 (Table 6.1), which was less than 0.5% of the dose limit, and unchanged from 2024. The representative person was an adult consuming locally collected marine plants at high rates, who also consumed fish (which largely determined the exposure) and spent time on intertidal areas. The trend in annual ‘total dose’ at Devonport is for exposures that are consistently less than 0.005mSv (Table 1.3)

As in recent years, source-specific assessments for a high-rate consumer of locally grown food (including doses from external and inhalation from gaseous discharges), for fish and shellfish consumers, and for an occupant of a houseboat, gave exposures that were less than 0.005mSv in 2025 (Table 6.1).

6.4.2 Gaseous discharges and terrestrial monitoring

Permitted discharges of gaseous radioactive waste at Devonport are made to the atmosphere.

In 2025, gaseous discharges of argon-41 increased in comparison to those reported in 2024. Terrestrial samples (grass and potatoes) were analysed for several radionuclides (Table 6.3(a)). Activity concentrations in terrestrial samples were reported as ‘less than values’ in 2025.

6.4.3 Liquid waste discharges and aquatic monitoring

Permitted discharges of liquid radioactive waste are made to the Hamoaze, which is part of the Tamar estuary and to the local sewer.

The trends of tritium and cobalt-60 discharges over time (2014 to 2025) are given in Figure 6.3. The main contributor to the variations in tritium discharges over time has been the re-fitting of Vanguard class submarines. These submarines have a high tritium inventory as they do not routinely discharge primary circuit coolant until they undergo refuelling at Devonport. Cobalt-60 discharges have declined more substantially than tritium discharges since the early 2000s (Environment Agency and others, 2018). This reduction is largely attributable to improvements in submarine reactor design, which have decreased the production of cobalt-60 during operation and, consequently, reduced releases during submarine maintenance activities

Figure 6.3(a). Trends in liquid discharges of tritium, in GBq y^-1, from Devonport, Devon 2014 to 2025.

Year	Tritium discharge, GBq y-1
2014	22
2015	48
2016	18
2017	29
2018	12
2019	5.0
2020	8.4
2021	11
2022	2.4
2023	2.9
2024	20
2025	11

Figure 6.3(b). Trends in liquid discharges of cobalt-60, in MBq y^-1, from Devonport, Devon 2014 to 2025.

Year	60Co discharge, MBq y-1
2014	25
2015	35
2016	39
2017	28
2018	16
2019	4.7
2020	3.2
2021	2.6
2022	2.5
2023	1.8
2024	3.1
2025	1.8

Concentrations of tritium and cobalt-60 in marine samples were reported as ‘less than values’ in 2025 as they were in 2024. Low caesium-137 concentrations, likely to originate from other sources (such as nuclear weapons testing), were measured in sediment samples. Carbon-14 concentrations in seafood species were generally similar to those in previous years. The seaweed samples obtained in 2025 contained concentrations of iodine-131, this was most likely to have originated from the therapeutic use of this radionuclide in local hospitals, as iodine-131 is not discharged by the site. Gamma dose rates in the vicinity of Devonport in 2025 were similar to those in recent years and reflect the local effects of enhanced background radiation from natural sources. The results are given in Table 6.3(a) and Table 6.3(b).

6.5. Faslane and Coulport, Argyll and Bute

The His Majesty’s Naval Base Clyde establishment consists of the naval base at Faslane and the armaments depot at Coulport. Babcock Marine, a subsidiary of Babcock International Group plc, operates His Majesty’s Naval Base Clyde, Faslane in partnership with the MOD. However, the MOD remains in control of the undertaking, through the Naval Base Commander, Clyde (NBC Clyde) in relation to radioactive waste disposal. MOD through NBC Clyde also remains in control of the undertaking at Coulport although many of the activities undertaken at Coulport have been outsourced to an industrial alliance comprising of AWE plc, Babcock and Lockheed Martin UK (known as ABL).

From the 1st of January 2025 discharges of liquid and gaseous radioactive waste were made under a single Letter of Approval (LoA) which covers both the Faslane and Coulport sites. The single LoA is a new approach and combines the previous four Letters of Agreement that had been in place for many years. The new LoA is generally more restrictive than the previous LoA’s with the limits on existing discharges being significantly reduced and some disposal pathways limited for the first time. See Appendix 1 (Tables A1.1 and A1.2) for a summary of the discharge limits for all sites, including Faslane and Coulport.

Construction of the Nuclear Support Hub (NSH) facility at Faslane was completed in 2023, and commissioning of the NSH will continue in 2026.

Gaseous tritium discharges from Coulport were broadly similar in 2025 to those in recent years. Gaseous discharges from Faslane consisted of tritium and a small amount of waste from other radionuclides in 2025, and liquid discharges were limited solely to tritium in general effluents (see Appendix 1, Table A1.1 and Table A1.2, respectively).

Solid waste transfers in 2025 are given in Appendix 1 (Table A1.4).

The most recent habits survey to determine the consumption and occupancy rates by members of the public was undertaken in 2023. The report is available on SEPA Habits survey reports, and copies can also be requested from SEPA by emailing RSEnquiries@sepa.org.uk.

The ‘total dose’ from all pathways and sources of radiation was 0.007mSv in 2025 (Table 6.1), which was less than 1% of the dose limit to members of the public. This is similar to the value of 0.005mSv for 2024. The representative person was an adult consuming fish at high rates and was unchanged from 2024. Activity concentrations in fish (not collected in recent years) were estimated using reported environmental fish data in 2025, sampled outside the aquatic habits survey area of this site, but within the Firth of Clyde. The assessment of this ‘total dose’ was therefore highly conservative, due to the assumption of fish concentration data. In 2025, the source-specific assessment for a high-rate consumer of shellfish, which is based on limited data, gave an exposure of 0.008mSv, which was also similar to the 2024 value (0.006mSv). The dose to a consumer of locally grown food, was less than 0.005mSv and unchanged from 2024.

The routine marine monitoring programme consisted of the analysis of seawater, seaweed and sediment samples, and gamma dose rate measurements. Terrestrial monitoring included meat, honey, water, grass and soil sampling. The results in 2025 are given in Table 6.3(a) and Table 6.3(b) and were generally similar to those in recent years. Caesium-137 was positively detected at a low concentration in honey (as in recent years). Caesium-137 was also positively detected in sediment and soil. The measured concentrations are consistent with the distant effects of discharges from Sellafield, fallout from Chernobyl and nuclear weapons testing. Other radionuclide concentrations were generally reported as ‘less than values’ in 2025. Concentrations of tritium, gross alpha and gross beta were much lower than the investigation levels in the Water Supply (Water Quality) (Amendment) 2018 Regulations (retained from the European Directive 2013/51).

Gamma dose rates measured in the surrounding area were difficult to distinguish from natural background (Table 6.3(b)).

6.6. Rosyth, Fife

The Rosyth naval dockyard is located on the north bank of the River Forth in Fife, 3km west of the Forth Road Bridge and some 50km from the mouth of the Firth of Forth. It is sited on reclaimed land, with reclamation completed in 1916. From 1916, the site was known as HM Dockyard Rosyth and activities conducted there included refitting and maintaining warships.

In 1997, Rosyth Royal Dockyard Limited (RRDL), a wholly owned subsidiary of Babcock International Group Marine Division, was set up to be responsible for the decommissioning of the dockyard site and the management of radioactive waste that had arisen from the re-fitting of nuclear submarines which ended in 2003. Site decommissioning started in 2006 and has mainly been completed, except for some small areas of the site where facilities are required to continue managing radioactive wastes.

The MOD sold the site to Babcock International Group Marine Division who now manage and operate the site. However, radioactive waste that was generated by the site, to support the nuclear submarine fleet, is owned by the MOD. Therefore, the MOD has entered into a contract with RRDL to manage all radioactive waste on the dockyard site. As the radioactive waste owner, the MOD maintains an overview of procedures to ensure RRDL fully complies with the terms and conditions of its contract.

In 2016, SEPA granted RRDL an authorisation (under Radioactive Substances Act 1993) to dispose of radioactive waste arising on the Rosyth dockyard site. This allows RRDL to dispose of LLW that arises from the decommissioning of the Rosyth premises, from former submarine re-fitting operations and from waste transferred from the MOD from the dismantling of the 7 redundant nuclear submarines currently stored afloat at the dockyard site. The authorisation was transitioned to a permit under the Environmental Authorisations (Scotland) Regulations 2018 (EASR) with a new permit being issued in March 2019. In 2023, RRDL applied for a permit variation to allow the management of intermediate level waste from the dismantling of the 7 submarines stored at the dockyard. A Letter of Approval (LoA) (effective from 2016) to the MOD allows the transfer of LLW from the 7 nuclear submarines berthed at the Rosyth dockyard site to RRDL. Granting of the LoA and new authorisation to RRDL has permitted the start of the MOD submarine dismantling programme at Rosyth. Work to dismantle and remove radioactive and conventional wastes from each submarine and subsequently clean up the Rosyth site is expected to take up to 15 years to complete. A new LoA was issued to the MOD in April 2025 in line with the Memorandum of Understanding between SEPA and the MOD. The LoA has been applied to the submarines whilst afloat in the main basin at Rosyth and under the control of MOD Clyde. The submarine in dry dock number 2 and under RRDL control is being dismantled under the permit granted to RRDL.

The most recent habits survey was undertaken in 2022, and copies of the report are available from SEPA by emailing RSEnquiries@sepa.org.uk.

The ‘total dose’ from all pathways and sources of radiation was 0.007mSv in 2025 (Table 6.1), which is less than 1% of the dose limit to members of the public. In 2025, the representative person was an adult consuming crustacean shellfish at high rates, and this was unchanged from 2024. The decrease in ‘total dose’ was mainly attributed to a decrease in the gamma dose rate measured over sediments in 2025. The source-specific assessment for marine pathways (fishers and beach users) was estimated to be 0.005mSv in 2025 (a decrease from 0.008mSv in 2024). The reason for the decrease in dose was the same as that contributing to the maximum ‘total dose’.

The gaseous and liquid discharges from Rosyth in 2025 are given in Appendix 1 (Table A1.1 and Table A1.2, respectively), and solid waste transfers in Table A1.4. Liquid wastes are discharged via a dedicated pipeline to the Firth of Forth.

The direct radiation from the site was less than 0.001mSv in 2025 (Table 1.1). This was unchanged from 2024. This value of direct radiation is based upon actual measurements and is a more representative background radiation measurement location.

SEPA’s routine monitoring programme included analysis of shellfish, environmental indicator materials and measurements of gamma dose rates in intertidal areas. Results are shown in Table 6.3(a) and Table 6.3(b). The radioactivity concentrations measured in freshwater samples were low in 2025 and similar to those observed in recent years, and in most part due to the combined effects of Sellafield, weapon testing and Chernobyl. Gamma dose rates were slightly higher in 2025 than in 2024 but, as in previous years, were difficult to distinguish from natural background at all measurement locations.

6.7 Vulcan NRTE, Highland

The Vulcan Naval Reactor Test Establishment (NRTE) is operated by the Submarine Delivery Agency, part of the MOD, and its purpose was to prototype submarine nuclear reactors. It is located adjacent to the Dounreay site, and the impact of its discharges is considered along with those from Dounreay (in Section 5). The transfer of solid and aqueous waste to NRS Dounreay and the disposal of gaseous waste are made under a LoA between SEPA and the MOD. It is intended to transition the LoA to replicate an EASR permit in line with the current Memorandum of Understanding between SEPA and the MOD.

Ownership of the site will be transferred from MOD to the NDA for decommissioning once operations have been completed (and subject to regulatory approval).

Gaseous discharges, and solid waste transfers, from Vulcan NRTE in 2025 are given in Appendix 1 (Table A1.1 and Table A1.4, respectively).

7. Industrial, solid waste disposal, legacy and other non-nuclear sites

Highlights

• doses (dominated by the effects of legacy discharges from other sources) increased at the Low Level Waste Repository in 2025
• doses at solid waste disposal sites were less than 0.5% of the dose limit in 2025
• doses (dominated by the effects of naturally occurring radionuclides from legacy discharges) increased at Whitehaven in 2025 compared to 2024

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This section considers the results of monitoring by the Environment Agency, FSA, FSS, NRW and SEPA for industrial, solid waste disposal, legacy and other non-nuclear sites that may have introduced radioactivity into the environment such as:

• the main disposal site for solid radioactive wastes in the UK, at the LLWR in Cumbria, as well as a recycling facility and other solid waste disposal sites that received small quantities of solid wastes
• one legacy site in England, near Whitehaven, Cumbria, which was used to manufacture phosphoric acid from imported phosphate ore
• two legacy sites in Scotland, at Dalgety Bay, Fife, and Kinloss, Moray
• other non-nuclear sites

Data tables and the detailed results of the dose assessments, in Open Document Spreadsheet (ODS) format, are downloadable from the main RIFE page.

7.1. Low Level Waste Repository, Cumbria

The LLWR is the UK’s national facility for the disposal of lower activity waste and is located on the west Cumbrian coast, southeast of Sellafield. The main function of the LLWR is to receive low-activity solid and non-aqueous liquid radioactive wastes from all UK nuclear sites (except Dounreay, where the adjacent disposal facility began accepting waste in 2015) and many non-nuclear sites. Where possible, the waste is compacted before transfer to the site and then most waste is grouted on site within containers before disposal. Wastes are currently disposed of in engineered concrete vaults on land, whereas prior to the early 1990s waste was disposed of in open clay lined trenches.

The site is owned by the NDA and operated on their behalf by Nuclear Waste Services (NWS). In 2018, the NDA awarded the incumbent Parent Body Organisation, UK Nuclear Waste Management Limited, a third (and final) contract for the management of LLWR Limited. In January 2022, NWS was launched. This brought together the operator of the LLWR, Geological Disposal Facility developer Radioactive Waste Management Limited and the NDA group’s integrated waste management programmes into a single organisation.

NWS published a major review of their Environmental Safety Case in May 2026. This consists of a suite of documents including an optimisation and site development plan, which sets out plans for the long-term future of the site through to final closure, expected around 2135 (Nuclear Waste Services 2026c).

The disposal permit allows for the discharge of leachate from the site through a marine pipeline. These discharges are small compared with those discharged from the nearby Sellafield site (Appendix 1). Monitoring of the marine environment close to the LLWR is therefore subsumed within the Sellafield programme, described in Section 3.3. The contribution to exposures due to LLWR discharges is negligible compared with that attributable to Sellafield and any effects of LLWR discharges in the marine environment could not, in 2025, be distinguished from those due to Sellafield.

The current permit allows for continued solid radioactive waste disposal at the site, including permission to dispose of further radioactive waste beyond Vaults 8 and 9, and limits disposals against a lifetime capacity for the site. In 2019, Revised Joint Waste Management Plans were published for the NDA’s radioactive waste-producing site licence companies (LLWR Limited (now NWS), Magnox Limited (now NRS Limited) and Sellafield Limited), covering the financial years, 2019/20 to 2024/25. More information can be found at the UK government’s website: joint waste management plan.

Waste received at the site will have a final disposal location allocated to it at the appropriate time. Table A1.3 records, for the financial year 2025/26, both solid radioactive wastes already disposed in Vault 8 and the solid radioactive wastes accepted for disposal by the site currently located within Vault 9, pending placement in its final disposal position. A total of 239m³ of waste was received by the site with the intention of disposal in financial year 2025/26, bringing the cumulative total to 235,000m³. The data given in Table A1.3 are recorded by financial year, instead of calendar year. All activities in terms of waste accepted for disposal have been within the lifetime capacity for the site.

Although the permit for routine disposal to the Drigg Stream was revoked in 2006, reassurance monitoring has continued for samples of water and sediment. The results are given in Table 7.2. The tritium, gross alpha and gross beta concentrations in the stream were below the investigation levels for drinking water in the Water Supply (Water Quality) (Amendment) 2018 Regulations (retained from European Directive 2013/51). Although the stream is not known to be used as a source of drinking water, it is possible that occasional use could occur, for example by campers. If the stream was used as a drinking water supply for 3 weeks, the annual dose would be less than 0.005mSv. Concentrations of positively detected radionuclides (plutonium-238 and plutonium-239+240) in sediment from the Drigg stream were very low and similar to those in previous years. They reflect the legacy of direct discharges of leachate from the disposal site into the stream which stopped in 1991 (Nuclear Waste Services 2026d).

In the past, groundwater from some of the trenches on the LLWR site migrated eastwards towards a railway drain that runs along the perimeter of the site. Radioactivity from the LLWR was detected in the drain water. The previous operators of the site, British Nuclear Fuels plc (BNFL), took steps in the early 1990s to reduce migration of water from the trenches by building a ‘cut-off wall’ to reduce lateral migration of leachate. The results of monitoring in 2025 show that the activity concentrations have continued to be very low in the railway drain (Table 7.2) and have reduced significantly since the construction of the cut-off wall. Tritium, gross alpha and gross beta concentrations in the drain were also below the investigation levels for drinking water in the Water Supply (Water Quality) (Amendment) 2018 Regulations (retained from European Directive 2013/51).

The monitoring programme of terrestrial foodstuffs at the site was primarily directed at the potential migration of radionuclides from the waste burial site via groundwater, since gaseous wastes releases are very small. Results for 2025 are given in Table 7.2 and do not indicate that radioactivity in leachate from the LLWR might be transferring to foods. Concentrations of radionuclides were generally similar to (or lower than) those measured near Sellafield (Section 3.3). The latest habits survey for the LLWR was undertaken in 2023 and the results have been included in the dose assessments for the site (Moore and others, 2024b).

The ‘total dose’ from all pathways and sources of radiation was 0.51mSv in 2025, or 51% of the dose limit for members of the public of 1mSv (Table 1.2 and Table 7.1) and includes a component due to the fallout from Chernobyl and nuclear weapons testing. This dose was dominated by the effects of naturally occurring radionuclides discharged to sea from the former phosphate works at Whitehaven, with smaller contributions from legacy discharges into the sea from Sellafield and sources of direct radiation on site. If these effects were to be excluded, and only the sources of exposure from the LLWR are considered, the ‘total dose’ from gaseous releases and direct radiation was 0.029mSv in 2025 (Table 1.2). The representative person was an adult living near the site and unchanged from 2024. The decrease in ‘total dose’ (from 0.030mSv in 2024) was mostly due to a lower estimate of direct radiation. A source-specific assessment of exposure for consumers of locally grown terrestrial food (animals fed on oats), using 2025 modelled activity concentrations in animal products, gives an exposure that was less than 0.005mSv in 2025, and lower to that in recent years.

7.2. Metals Recycling Facility, Lillyhall, Cumbria

The Metals Recycling Facility (MRF), operated by Cyclife UK Limited, is located at the Lillyhall Industrial Estate near Workington in Cumbria. The MRF predominantly receives metallic waste items contaminated with low quantities of radiological contamination from clients within the UK nuclear industry which are processed in batches. Techniques used include size reduction using conventional hot and cold cutting methods, with subsequent decontamination using industrial grit blasting equipment.

The permit for the MRF site allows discharges of low-activity gaseous waste to the environment via a main stack and of aqueous waste to the sewer. All discharges in 2025 were within permitted limits (Appendix 1, Table A1.1 and Table A1.2). As in recent years, direct radiation from the site was less than 0.001mSv in 2025 (Table 1.1) and the radiological impact was low.

A habits survey, focusing on direct radiation pathways, was undertaken in 2018 (Clyne 2021). This was the first habits survey to be carried out at the MRF, and it was undertaken to ensure consistency with other nuclear sites in the UK. The qualitative survey focussed on the area adjacent to the waste container park that had resulted in elevated dose rates being recorded in 2016. Quantitative habits data were not obtained as the time spent by members of the public undertaking activities in the area was minimal.

7.3 Tradebe-Inutec, Winfrith, Dorset

The Tradebe-Inutec site is a radiological waste processing facility, for the wider nuclear industry, located adjacent to the NRS Winfrith site. In 2019, Tradebe-Inutec acquired buildings and land at Winfrith from the NDA and the ONR and Environment Agency granted a new nuclear site licence and environmental permit transfer (respectively) to Inutec Limited, who trade as Tradebe-Inutec. Prior to this, Tradebe-Inutec had been operating as a tenant of Magnox Limited, now NRS. The impact of its site operations and gaseous discharges is considered along with those from the NRS Winfrith site (in Section 5.4).

Gaseous discharges from Tradebe-Inutec are also made via stacks to the local environment and are given in Appendix 1 (Table A1.1). As in recent years, discharges of alpha, carbon-14 and other radioelements were less than 1% of the discharge limits. The discharge of tritium increased in 2025 in comparison to 2024. These discharges were associated with a campaign of treating tritiated solid waste, with higher activity items being processed between February and December 2025. As in 2024, the dose from direct radiation from the Tradebe-Inutec site was low and reported as <0.001mSv (Table 1.1).

Liquid waste from Tradebe-Inutec is transferred off site for disposal into Southampton Water under a non-nuclear permit (included in Table 7.7) and therefore these impacts are not considered in the RIFE report.

7.4. Other solid waste disposal sites

SEPA, the Environment Agency and NRW grant permits to dispose of solid waste containing low levels of radioactivity at approved landfill sites. In Northern Ireland, this type of waste is transferred to Great Britain for incineration. Waste with very low quantities of radioactivity can also be disposed of in general refuse.

The UK government introduced a more flexible framework in 2024 for the disposal of certain categories of LLW to landfill. Further details and information are provided on the website: UK policy framework for managing radioactive substances and nuclear decommissioning.

In England and Wales, disposal of LLW at landfill sites requires both landfill companies and nuclear operators to hold permits to dispose of LLW and very low-level waste (VLLW). The 2007 government policy led to applications from landfill operators for permits to dispose of LLW at their sites. The landfill sites were:

• Waste Recycling Group Limited (part of FCC Environmental) at the Lillyhall Landfill Site in Cumbria. Their revised permit, issued in 2021, allows disposal of very low-level waste
• Augean at the East Northants Resource Management Facility (ENRMF), near Kings Cliffe, Northamptonshire. Their permit, issued in 2016, allows the disposal of low activity LLW and very low-level waste. The Environment Agency undertook a baseline survey as described in previous RIFE reports (for example Environment Agency and others, 2014; Environment Agency and others, 2015)
• Suez Recycling and Recovery UK Limited (formerly SITA UK) at Clifton Marsh in Lancashire. A permit to dispose of LLW was issued by the Environment Agency in 2012

Radioactivity in wastes can migrate into leachate and in some cases can enter the groundwater. SEPA and the Environment Agency carry out monitoring of leachates and off-site watercourses. The locations of landfill sites considered in 2025 are shown in Figure 7.1 and the results are presented in Table 7.3 and Table 7.4, alongside the respective regions and locations.

Figure 7.1. Solid waste disposal sites monitored in 2025.

The results, in common with previous years, showed evidence for migration of tritium from some of the disposal sites. The reported tritium concentrations vary from year to year. The variation is thought to be related to changes in rainfall quantity and resulting leachate production and the use of different boreholes for sampling. A possible source of the tritium is thought to be due to disposal of Gaseous Tritium Light Devices (Mobbs, Barraclough & Napier 1998). As in recent years, inadvertent ingestion of leachate (2.5 litres per year) from the Cathkin landfill (City of Glasgow) site (with the highest observed concentration of tritium) would result in a dose of less than 0.005mSv in 2025 (Table 7.1), or less than 0.5% of the dose limit for members of the public of 1mSv. Similarly, the annual doses from ingestion of uranium isotopes in leachate from Clifton Marsh and inadvertent ingestion of borehole or surface water close to the East Northants Resource Management Facility were also less than 0.005mSv in 2025. The latter assessment excludes potassium-40 because its presence is homeostatically controlled in the body.

Gross beta concentrations in off-site watercourses were below the investigation levels for drinking water in the Water Supply (Water Quality) (Amendment) 2018 Regulations (retained from the European Directive 2013/51).

SEPA’s monitoring programme at the Stoneyhill Landfill Site in Aberdeenshire, authorised to dispose of conditioned NORM waste, ceased in 2016. Results up to 2015 are included in earlier RIFE reports and show no significant radiological impact (for example Environment Agency and others, 2016).

NORM is found within oil and gas reserves and is consequently extracted along with the oil and gas. The NORM can precipitate onto oil and gas industry equipment, creating an insoluble scale (NORM scale). The presence of this scale reduces the efficiency of the equipment and must be removed. Suez Recycling and Recovery UK Limited, the operators of the Stoneyhill Landfill site, has constructed a descaling facility adjacent to the landfill in partnership with Nuvia Limited. This facility descales oil and gas industry equipment, such as pipes, using pressurised water. The solid scale removed from the equipment is then grouted into drums and can be consigned to Stoneyhill Landfill site in accordance with the authorisation granted in 2012.

7.5. Former phosphate processing plant, Whitehaven, Cumbria

An important historical anthropogenic source of naturally occurring radionuclides in the marine environment was the former phosphate processing plant, which used to manufacture phosphoric acid (for use in detergents) from imported phosphate ore (Rollo and others, 1992). Processing of ore resulted in a liquid waste slurry (phosphogypsum) containing most of the thorium, uranium and radioactive decay products (including polonium-210 and lead-210) originally present in the ore, and this was discharged by pipeline to Saltom Bay.

The slurry is regarded as NORM from industrial activity. Historical discharges continue to have an impact through the production of the radioactive products. This impact is due to the decay of long-lived parent radionuclides previously discharged to sea. Both polonium-210 and lead-210 are important radionuclides in that small changes in activity concentrations above background significantly influence the dose contribution from these radionuclides. This is due to their relatively high dose coefficients used to convert an intake of radioactivity into a radiation dose.

Processing of phosphoric acid at the plant ceased at the end of 2001. The plant was subsequently decommissioned and the authorisation to discharge radioactive wastes was revoked by the Environment Agency.

The results of routine monitoring for naturally occurring radioactivity near the site in 2025 are shown in Table 7.5. Routine analytical effort is focused on polonium-210 and lead-210, which concentrate in marine species and are the important radionuclides in terms of potential dose to the public. As in previous years, polonium-210 and other naturally occurring radionuclides were slightly enhanced near Whitehaven but reduced to background values further away. Figure 7.2 to Figure 7.4 show how concentrations of polonium-210 in winkles, crabs and lobsters have generally decreased since 1998, with larger concentration variations in lobsters since 2014. Concentrations in the early 1990s were more than 100Bq kg^-1 (fresh weight), when discharges were taking place, prior to a change in site operations (in 1992) and later plant closure in 1997. There were some variations in concentrations of polonium-210 in local samples in 2025 (where comparisons can be made), in comparison with those in 2024. Polonium-210 concentrations in Parton crab were higher in 2025 than those in 2024. Polonium-210 concentrations in lobsters were similar to those reported in 2024. As in recent years, these concentrations continued to be within or close to the expected range due to natural sources. For crustacean and other seafood samples, it is now difficult to distinguish between the measured radionuclide concentrations and the range of concentrations normally expected from naturally sourced radioactivity. The latter are shown in Figure 7.2 to Figure 7.4 and in Appendix 6 (minimum, median and maximum concentrations of polonium-210 in each species, as reported in Young, McCubbin & Camplin 2002; Young and others, 2003). There were small enhancements for some samples at other locations above the expected natural background median values for marine species, however, the majority were within the ranges observed in the undisturbed marine environment. It is considered prudent to continue to estimate doses at Whitehaven whilst there remains an indication that concentrations are higher than natural background. Further analysis has confirmed that this approach is unlikely to underestimate doses (Dewar and others, 2014).

Figure 7.2. Polonium-210 concentration, in Bq kg^-1 (fresh), in winkles at Parton, 1996 to 2025.

Figure 7.3. Polonium-210 concentration, in Bq kg^-1 (fresh), in crabs at Parton, 1996 to 2025.

Figure 7.4. Polonium-210 concentration, in Bq kg^-1 (fresh), in lobsters at Parton, 1996 to 2025.

In 2018, the Environment Agency, with the support of the FSA, NIEA and SEPA, performed additional polonium-210 analyses in shellfish samples to obtain baseline data, providing naturally sourced polonium-210 concentrations that are unlikely to be influenced by NORM in the Irish Sea. Further details are presented in RIFE 24 (Environment Agency and others, 2019).

The exposure pathway considered for the assessment at Whitehaven was internal irradiation, due to the ingestion of naturally occurring radioactivity in local fish and shellfish. The representative person was a Cumbrian coastal community consumer who, centred on the Sellafield site to the south of Whitehaven, obtained their sources of seafood from locations such as Whitehaven, Nethertown and Parton. This consumer is also considered in the assessment of the marine impacts of the Sellafield and LLWR sites (Sections 3.3 and 7.1). The estimated contribution due to background median concentrations of naturally occurring radionuclides is subtracted from the measured activity concentration. Consumption rates for people who eat seafood at high rates were reviewed and revised in 2025 (Moore, Clyne, Greenhill & Wylie 2026). Revised figures for consumption rates, together with occupancy rates, are provided in Appendix 4 (Table A4.2). The dose coefficient for polonium-210 is based on a value of the gut transfer factor of 0.5 for all foods.

The ‘total dose’ to a local high-rate consumer of seafood was 0.51mSv in 2025 (Table 7.1), or 51% of the dose limit to members of the public. This is an increase from 0.20mSv in 2024. The dose includes the effects of all sources near the site as explained in Section 3. The contribution to the ‘total dose’ from enhanced natural radionuclides was 0.49mSv and was higher in 2025, compared to that in 2024 (0.18mSv). The increase in ‘total dose’ in 2025 was mostly attributed to higher concentrations of polonium-210 in crab (at Parton) and to a lesser extent the revision of crustacean consumption rate. The largest contribution to dose to a Cumbrian coastal community seafood consumer near Whitehaven and Sellafield continues to be from historical discharges near Whitehaven. A source-specific dose assessment targeted directly at local consumers of seafood (at high rates), gives an exposure of 0.44mSv in 2025 (Table 7.1).

The longer-term trend in annual ‘total dose’ over the period 2014 to 2025 is shown in Figure 7.5. The variations in ‘total dose’ over the period 2014 to 2025 reflect changes in polonium-210 concentrations, consumption rates and the range of seafood species consumed by individuals at high-rates, including that of crustaceans. Over a longer period, the trend is of generally declining dose (Environment Agency and others, 2018).

Figure 7.5. Trend in ‘total dose’, in mSv y^-1, to seafood consumers from naturally- occurring radionuclides near Whitehaven, 2014 to 2025.

Year	Dose, mSv y-1
2014	0.15
2015	0.35
2016	0.34
2017	0.18
2018	0.33
2019	0.20
2020	0.25
2021	0.19
2022	0.22
2023	0.21
2024	0.18
2025	0.49

7.6. Holy Loch, Argyll and Bute

A small programme of monitoring at Holy Loch continued during 2025 to determine the effects of past discharges from the US submarine support facilities which closed in 1992. Radionuclide concentrations in the sediment sample collected in 2025 were low (Table 7.11(a)). Gamma dose rate measurements over intertidal areas (Table 7.11(b)) were similar to those values reported in recent years. As reported in previous RIFE reports (Environment Agency and others, 2024), no dose assessment is being undertaken for the site as there are no radioactive discharges to the loch and monitoring provides confidence that there is no realistic risk to the public using the area.

Should results from future monitoring indicate that a dose assessment is needed, this will be undertaken.

7.7. Former military airbase, Dalgety Bay, Fife

Radioactive items containing radium-226 and associated decay products have been detected at Dalgety Bay in Fife since at least 1990. The contamination is associated with historical disposals of waste from past military operations at the Royal Naval Air Station (RNAS) Donibristle, which closed in 1959 and upon which large areas of the town of Dalgety Bay have been built. The air station played a role as an aircraft repair, refitting and salvage yard. It is believed that waste was incinerated, and the resultant ash and clinker was disposed of by reclaiming land from the sea. Following years of erosion at the site, the contamination was being exposed on and adjacent to the foreshore. Some of the incinerated material contained items such as dials and levers which had been painted with luminous paint containing radium-226.

In 1990, environmental monitoring showed elevated activity concentrations in the Dalgety Bay area. The monitoring was undertaken as part of the routine environmental monitoring programme for Rosyth Royal Dockyard Limited conducted in accordance with the dockyard’s authorisation to dispose of liquid radioactive effluent to the Firth of Forth. Some material was removed for analysis, which indicated the presence of radium-226. Further investigation confirmed that the contamination could not have originated from the dockyard and was most likely to be associated with past practices related to the nearby former Royal Naval Air Station Donibristle or HMS Merlin military airfield. Since this initial discovery, there have been several monitoring exercises to determine the extent of this contamination. In 2017, SEPA issued guidance on monitoring for heterogeneous radium-226 sources resulting from historic luminising activities or waste disposal sites (Scottish Environment Protection Agency 2017).

Additional public protection measures were established following the increased number of particles and the discovery of some high activity particles in 2011. A monthly beach monitoring and particle recovery programme was adopted in 2012 by a contractor working on behalf of the MOD. The information signs advising the public of the contamination and precautions to be taken remain in place. In addition, the FEPA Order issued by FSS (then FSA in Scotland) prohibiting the collection of seafood from the Dalgety Bay area remains in force. SEPA undertook a one-year programme of shellfish monitoring from February 2012, during which no particles were detected in the shellfish. All shellfish samples collected were analysed for the presence of radium-226 and all were reported as ‘less than values’. During routine monitoring of mussel beds in 2015 a particle was detected in this area (for the first time since 2011) and retrieved, indicating that the continuation of these protection measures is reducing the risks to members of the public whilst further work continues to address the contamination.

The Committee on Medical Aspects of Radiation in the Environment (COMARE) recommended that effective remediation of the affected area be undertaken as soon as possible. This recommendation followed the publication of the Risk Assessment in 2013, which was considered alongside the Appropriate Person Report. This Appropriate Person Report included a comprehensive study of the land ownership and history at Dalgety Bay. The Committee on Medical Aspects of Radiation in the Environment recommendation, amongst others, was subsequently published in 2014 in Committee on Medical Aspects of Radiation in the Environment’s 15^th report. Copies of these reports are available on the UK government website: committee on medical aspects of radiation in the environment. The MOD progressed with addressing the contamination by initially publishing its Outline Management Options Appraisal Report in 2014, followed by a further publication in 2014 of its broad management strategy and timescale for implementation of its preferred management option.

The environmental impact assessment in support of the planning application for the remediation works was submitted to Fife Council for consideration. In 2017, the planning application for the remediation works was submitted to Fife Council and subsequently approved.

The remediation contract was awarded by the MOD in February 2020 and an EASR permit to undertake the required work was granted by SEPA in May 2021. Remediation work took place between 2021 and 2023. The works involved extraction of beach material which was then transferred to a compound where the material was screened for asbestos and then radioactive contamination on a conveyor system.

Asbestos material and oversized material were monitored for radioactive contamination separately by hand.

Screened material was then replaced onto the beach. This was covered with a geotextile membrane on top of which graded rock armour was fixed in place.

It is estimated that a total of over 13,000 items have been removed from the beach as a result of both the remediation works and previous monitoring undertaken since 1990.

Monthly monitoring of the foreshore, where possible, continued during the remediation by MOD contractors.

Monthly verification monitoring has been undertaken by MOD contractors following completion of the works. This will progress in 2026 and into 2027 on a less frequent basis due to the substantial reduction in items found on the foreshore since the remediation work was undertaken. By analysing the activity range and depth of particles recovered from the area, SEPA will determine if the remediation objective has been met. Following this, the site will then be regularly monitored by SEPA (radiological monitoring) and Fife Council (rock armour assessment).

Further details on the work at Dalgety Bay can requested by emailing RSEnquiries@sepa.org.uk.

7.8. Former military airbase, Kinloss Barracks, Moray

Radioactive items containing radium-226 and associated decay products have been detected on an area of land which used to form part of the former RAF Kinloss, now Kinloss Barracks. The contamination is associated with historical disposals of waste from past military operations at the site resulting from the dismantling of aircraft no longer required by the RAF following World War II. During the late 1940s, the aircraft were stripped for their scrap metal, with the remains being burnt and/or buried at the site. The source of the radium-226 and associated decay products are the various pieces of aircraft instrumentation which were luminised with radium paint.

SEPA has undertaken monitoring surveys at the site which positively identified the presence of radium-226 and has published an assessment of the risks posed to the public (Natural Scotland & Scottish Environment Protection Agency 2016). Currently, the site is largely undeveloped open land covered in gorse with several wind turbines and access tracks. The area has a few informal paths crossing the land that is used by visitors and dog walkers. The contamination detected at the site is all currently buried at depth. Current uses of the site do not involve intrusion into the ground to any significant depth; thus, there is no current pathway for exposure via skin contact, ingestion or inhalation. Exposure via external gamma irradiation is possible but is significantly below the relevant dose criteria detailed in the Radioactive Contaminated Land Statutory Guidance (Scottish Executive 2006:200; Scottish Government 2009).

The risk assessment of the series of monitoring surveys concluded that, under its current use, there are no viable or credible exposure pathways for the public to be exposed to the contamination and that this site does not currently meet the definition of radioactive contaminated land (Natural Scotland & Scottish Environment Protection Agency 2016). However, SEPA will keep this site under review as a change in land use on the site may alter the potential exposure pathways. To access the full risk assessment report, please email RSEnquiries@sepaorg.uk.

7.9. Other non-nuclear sites

Small quantities of gaseous and liquid radioactive wastes are routinely discharged from a wide range of other non-nuclear sites in the UK on land (including to the atmosphere from industrial stacks and incinerators), and from offshore oil and gas installations.

A summary of the most recent data for the quantities discharged under regulation for England and Northern Ireland in 2025 is given in Table 7.6 and Table 7.7. Data for Scotland are presented in Table 7.8 and Table 7.9 in terms of OSPAR regions (Region II represents the Greater North Sea and Region III the Celtic Sea). This change in format allows easier trend analysis to be performed for OSPAR. Data for Wales are presented in Table 7.10. The data are grouped according to the main industries giving rise to such wastes in the UK and exclude information for other industries considered in other sections of this report, principally the nuclear sector. The main industries are:

• oil and gas, both off and onshore
• education, including universities and colleges
• hospitals
• other, which includes research, manufacturing and public sector

Discharges may also occur without an authorisation or permit when the quantities are below the need for specific regulatory control. For example, discharges of natural radionuclides are made from coal-fired power stations because of the presence of trace quantities of uranium and thorium and their decay products in coal (Corbett, 1983).

As indicated in Section 1, general monitoring of the British Isles as reported elsewhere in this report has not detected any gross effects from non-nuclear sources. Occasionally, routine programmes directed at nuclear site operations detect the effects of discharges from the non-nuclear sector and, when this occurs, a comment is made in the relevant nuclear site text. The radiological impact of the radioactivity from the non-nuclear sector detected inadvertently in this way is very low.

Monitoring of the effect of the non-nuclear sector is limited because of the relatively low impact of the discharges. However, programmes are carried out to confirm that impacts are low and, when these occur, they are described in this report.

The Pharmaron UK radiolabelling facility in Cardiff, discharges tritium and carbon-14 to the atmosphere and to the marine environment, via the Cardiff sewage treatment works outfall. This site began operation after Quotient Bioresearch (Radiochemicals) Ltd in 2010 (later becoming Pharmaron UK in 2017) acquired GE Healthcare’s custom radiolabelling division which previously operated at the Maynard Centre in Cardiff (previously reported in RIFE (Environment Agency, Food Standards Agency, and others, 2012)). These operations were then moved to new premises in Cardiff, under a non-nuclear permit with lower discharge limits. Discharges from the Pharmaron UK facility are included in the discharges reported in Table 7.10. The radiological impacts of these discharges are low.

In 2025, SEPA continued to undertake a small-scale survey (as part of the annual programme) of the effects of discharges from non-nuclear operators by analysing mussel samples and other materials from the River Clyde, the Firth of Forth and sludge pellets from a sewage treatment works (at Daldowie). The results are given in Table 7.12. The results in 2025 were generally similar to those in 2024. Activity concentrations were typical of the expected effects from Sellafield discharges at this distance and the presence of iodine-131 in sludge pellets (probably from a hospital source). An assessment was undertaken to determine the dose to the representative high-rate mollusc consumer. The dose was estimated to be less than 0.005mSv in 2025, or approximately 0.5% of the dose limit for members of the public, and unchanged from 2024.

Scotoil, in Aberdeen City, operates a cleaning facility for equipment from the oil and gas industry contaminated with enhanced concentrations of radionuclides of natural origin. The facility is authorised to discharge liquid effluent to the marine environment within the limitations and conditions of the authorisation, which includes limits for radium-226, radium-228, lead-210 and polonium-210 discharges. The authorisation includes conditions requiring Scotoil to undertake environmental monitoring. Prior to their operations, a fertiliser manufacturing process was operated on the site and made discharges to sea. Monitoring of seaweed (‘Fucus vesiculosus’) from Nigg Bay, near Aberdeen Harbour was carried out in 2025 and are reported in Table 3.11. In 2025, the dose rate on sediment was 0.078µGy h^-1 and similar to background.

8. Regional monitoring

Highlights

• Doses for the representative person were approximately 1% (or less) of the annual public dose limit in 2025

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Regional monitoring in areas remote from nuclear sites continued in 2025:

• to establish long distance transport of radioactivity from UK and overseas nuclear sites
• to indicate general contamination of the food supply and the environment
• to provide data under UK obligations for the OSPAR Convention

The routine component parts of this programme are:

• sampling of seafood and environmental samples from the Channel Islands and Northern Ireland
• monitoring UK ports of entry for foodstuffs for other non-specific contamination
• sampling of the UK food supply, air, rain, sediments, sources of drinking water and seawater.

Data tables and the detailed results of the dose assessments, in Open Document Spreadsheet (ODS) format, are downloadable from the main RIFE page.

8.1. Channel Islands

Samples of marine environmental materials were provided by the Channel Island States of Jersey and Guernsey and analysed for a range of radionuclides, monitoring around Alderney ceased in 2019 (Environment Agency and others, 2020). The programme monitors the effects of radioactive discharges from the French reprocessing plant at La Hague and the power station at Flamanville. It also monitors any effects of historical disposals of radioactive waste in the Hurd Deep, a natural trough in the western English Channel. Fish and shellfish are monitored to determine exposure from the internal radiation pathway, and sediment is analysed for external exposures. Seawater and seaweeds are sampled as environmental indicator materials, and, in the latter case, because of their use as fertilisers. A review of marine radioactivity in the Channel Islands from 1990 to 2009 has been published (Hughes, Runacres & Leonard 2011).

The results of monitoring for 2025 are given in Table 8.1. There was evidence of routine releases from the nuclear industry in some food and environmental samples (for example, technetium-99). However, activity concentrations in shellfish were low and similar to those in previous years. It is generally difficult to attribute the results to different sources, including fallout from nuclear weapons testing, due to the low values detected. No evidence for significant releases of activity from the Hurd Deep site was found.

In 2025, the dose to the representative person, consuming large amounts of fish and shellfish was estimated to be less than 0.005mSv, or less than 0.5% of the dose limit for members of the public. The assessment included a contribution from external exposure. The concentrations of artificial radionuclides in the marine environment of the Channel Islands and the effects of discharges from local sources, therefore, continued to be of negligible radiological significance.

The collection of milk and crop samples from the Channel Island States ceased in 2014. Results up to 2013 are included in earlier RIFE reports (for example Environment Agency and others 2013) and the data indicated no significant effects from UK or other nuclear installations.

8.2. Isle of Man

Following review of their monitoring programmes, the FSA’s terrestrial and aquatic monitoring and the Environment Agency’s marine monitoring on the Isle of Man ceased in 2013 and 2016, respectively, see References (Environment Agency and others, 2014; Environment Agency and others, 2015; Environment Agency and others, 2016; Environment Agency and others, 2017) for more details. Results up to 2015 are included in earlier RIFE reports (for example (Environment Agency and others, 2016)). Previous results have demonstrated that there has been no significant impact on the Isle of Man from discharges to sea from mainland nuclear installations in recent years.

The Government of the Isle of Man undertakes their own independent radioactivity monitoring programme and provides an indication of the far-field effects of current and historical discharges from Sellafield and other UK nuclear sites. These are reported annually: Isle of Man environmental radioactivity

8.3. Northern Ireland

The NIEA monitors the far-field effects of liquid discharges from Sellafield into the Irish Sea. The programme involved sampling fish, shellfish, and indicator materials from a range of locations along the coastline (Figure 8.1). The sample species, type and locations are listed in the respective site tables. Gamma dose rates were measured over intertidal areas to assess the external exposure pathway. The results of monitoring are given in Table 8.2(a) and Table 8.2(b).

Figure 8.1. Monitoring locations in Northern Ireland, 2025.

In 2025, the main effect of discharges from Sellafield was observed in concentrations of technetium-99 in shellfish and seaweed samples. These were similar to values reported in recent years, reflecting the considerably decreased inputs to the Irish Sea (see also Section 3.3.3). Caesium-137 concentrations were low and generally similar to those in 2024 and over the period 2002 to 2025. As expected, low concentrations of transuranic radionuclides were also detected in 2025. Reported concentrations are less than those found nearer to Sellafield and continued to be low, as in recent years (Figure 8.2 to Figure 8.4). Further information on the trends in radioactivity in the marine environment of Northern Ireland has been published (Ly and others, 2015). The gamma dose rates over intertidal areas were similar to those in previous years.

Figure 8.2. Concentrations of americium-241 and caesium-137, in Bq kg^-1 (dry), in coastal sediments at Portrush, Northern Ireland, 2002 to 2025.

Figure 8.3. Concentrations of americium-241 and caesium-137, in Bq kg^-1 (dry), in coastal sediments at Ballymacormick, Northern Ireland, 2002 to 2025.

Figure 8.4. Concentrations of americium-241 and caesium-137, in Bq kg^-1 (dry), in coastal sediments Carlingford Lough, Northern Ireland, 2002 to 2025.

A survey of consumption and occupancy in coastal regions of Northern Ireland established the habits of people consuming large quantities of fish and shellfish (Smith and others, 2002). Based on the monitoring results from the marine environment in 2025, the annual dose from the consumption of seafood and exposure over intertidal areas was 0.007mSv (Table 3.15), or less than 1% of the dose limit for members of the public.

Monitoring results for the terrestrial environment of Northern Ireland are included in the following parts of Section 8.

8.4. General diet

As part of the UK government and devolved administrations’ general responsibility for food safety, concentrations of radioactivity are determined in regional diets. These data (and data on other dietary components in Sections 8.5 and 8.6) previously formed the basis of the UK submission to the European Commission. While these data are no longer supplied to the European Commission for England, Wales and Northern Ireland, they will continue to be published in the RIFE reports.

In 2025, the concentrations found in a survey of radioactivity in canteen meals collected across the UK, and mixed diets in Scotland, were very low or typical of natural sources (Table 8.3). Activity concentrations were generally similar to those in previous years.

8.5. Milk

The programme of milk sampling across dairies in the UK continued in 2025. The aim is to collect monthly milk samples and analyse them for their radionuclide content. This programme provides useful information with which to compare data from farms close to nuclear sites and other establishments that may enhance values above background activity concentrations.

The results of milk monitoring for 2025 are summarised in Table 8.4. Most results were similar to those in previous years (where comparisons can be made). The mean carbon-14 concentrations in England, Northern Ireland, Wales, and Scotland were all close to the expected background concentration in milk (see Appendix 6). The maximum concentrations of carbon-14 in milk for England (Lancashire), Northern Ireland (Co. Tyrone), Wales (Clywd), and Scotland (all regions) were 27Bq l^-1, 30Bq l^-1, 27Bq l^-1 and less than 15Bq l^-1, respectively. As in previous years, tritium concentrations were reported as ‘less than values’ at all remote sites. In 2025, strontium-90 concentrations were reported as ‘less than values’ (or just above the ‘less than value’), and the mean concentration over the UK was less than 0.034Bq l^-1 (compared to 0.034Bq l^-1 in 2024). In the past, the highest concentrations of radiocaesium in milk were from those regions that received the greatest amounts of fallout from Chernobyl. However, the concentrations are now very low, and it is not possible to distinguish this trend.

The radiation dose from consuming milk at average rates was assessed for various age groups. In 2025, the most exposed age group was infants (1-year-old). For the range of radionuclides analysed, the annual dose was 0.005mSv or 0.5% of the dose limit. Previous surveys (for example, Food Standards Agency & Scottish Environment Protection Agency 2002) have shown that if a full range of nuclides were to be analysed and assessed, the dose would be dominated by naturally occurring lead-210 and polonium-210, and artificial radionuclides would contribute less than 10% of the dose.

8.6 Crops

The programme of monitoring naturally occurring and artificial radionuclides in crops (in England, Wales and the Channel Islands) as a check on general food contamination (remote from nuclear sites) ceased in 2014. Further information on previously reported monitoring is available in earlier RIFE reports (for example Environment Agency and others, 2014).

8.7. Airborne particulate, rain, freshwater and groundwater

Radioactivity in rainwater and air was monitored at several UK locations as part of the programme of background sampling managed by the Environment Agency and SEPA. These data are collected on behalf of the DESNZ, NIEA and, the Scottish and Welsh Governments. The results of monitoring are given in Table 8.5. The routine programme is comprised of 2 components:

• regular sampling and analysis on a quarterly basis
• supplementary analysis on an ‘ad hoc’ basis

Tritium and caesium-137 concentrations in air and rainwater are reported as ‘less than values’ in 2025. Caesium-137 concentrations in air, as in recent years, remain less than 0.01% of those observed in 1986, the year of the Chernobyl reactor accident.

Concentrations of beryllium-7, a naturally occurring radionuclide formed by cosmic ray reactions in the upper atmosphere, were positively detected at similar values at all sampling locations. Peak air concentrations of this radionuclide tend to occur during spring and early summer, as a result of seasonal variations in the mixing of stratospheric and tropospheric air (Environment Agency 2002). Activity concentrations of the radionuclides reported in air and rainwater were very low and do not currently merit radiological assessment.

Sampling and analysis of sources of drinking water throughout the UK continued in 2025 (Figure 8.5). The sample locations and regions are listed in the respective site tables. These water data are collected by the Environment Agency (for England and Wales), NIEA (for Northern Ireland) and SEPA (for Scotland). Sampling was designed to represent the main sources of drinking water, namely reservoirs, rivers and groundwater boreholes. Most of the water samples were representative of natural waters before treatment and supply to the public water system.

Figure 8.5. Sources of drinking water sampling locations, 2025.

The results are given in Table 8.6 to Table 8.8 (inclusive). Tritium concentrations were all substantially below the investigation level for drinking water of 100Bq l^-1 in the Water Supply (Water Quality) (Amendment) 2018 Regulations (retained from European Directive 2013/51) (where applicable) and all are reported as ‘less than values’ except for one result). At Gullielands Burn (Table 8.6), which is near to the Chapelcross nuclear site, the tritium concentration was 9.2Bq l^-1 in 2025 (similar to that in recent years).

The mean annual dose from consuming drinking water in the UK was 0.024mSv in 2025 (Table 8.9), which is higher than the mean annual dose in 2024 (0.012mSv). The highest annual dose was estimated to be 0.027mSv for drinking water from River Faughan, County Londonderry. The estimated doses were dominated by naturally occurring radionuclides and are generally similar to those reported in previous years. The annual dose from artificial radionuclides in drinking water was less than 0.001mSv.

Collection and analysis of groundwater samples from across Scotland was not performed in 2025. Collection and analysis of these samples resumed in 2026 and will be reported in RIFE 32 and thereafter. Results up to 2019 are included in earlier RIFE reports (for example, (Environment Agency and others, 2020)).

8.8. Overseas incidents

Two overseas accidents have had direct implications for the UK: Chernobyl (1986) and Fukushima Dai-ichi (2011). Earlier RIFE reports have provided detailed results of monitoring by the environment agencies and the FSA (Environment Agency and others, 2013).

For Chernobyl, the main sustained impact on the UK environment was in upland areas, where heavy rain fell in the days following the accident, but activity concentrations have now reduced substantially. The results of monitoring and estimated doses to consumers are available in earlier RIFE reports.

During 2025, SEPA received a number of enquiries from the public in relation to windfarm construction activities and the potential impact of release of Chernobyl contamination. A dose assessment has been prepared and is available on SEPA’s website: Radioactivity and Wind Farm Developments on peatlands or by emailing RSEnquiries@sepaorg.uk. SEPA calculated that windfarm construction activities did not pose a realistic risk to public health. Samples of peat were collected and analysed during 2025, and the results are presented in Table 8.10.

The accident at the Fukushima Dai-ichi nuclear power station in Japan in March 2011 resulted in significant quantities of radioactivity being released into the air and sea. Controls on imported food and animal feed products from Japan were implemented in 2011 (revised in 2016 and 2019). These controls were revoked in June 2022 for Great Britain (England, Wales and Scotland).

In Northern Ireland, European Regulations continued to apply under the terms of the UK’s withdrawal agreement from the EU, until July 2023 when these regulations were repealed by the EU (under 2023/1453).

A full description of the legislation, requirements and procedures for imports are provided in earlier RIFE reports (Environment Agency, Food Standards Agency and others, 2021).

Screening instruments are used at importation points of entry to the UK as a general check on possible contamination from unknown sources. In 2025, these instruments were not triggered by a food consignment at any point of entry into the UK.

8.9. Seawater surveys

The UK government and devolved administrations are committed to preventing pollution of the marine environment from ionising radiation, with the main aim of reducing concentrations in the environment to near background values for naturally occurring radioactive substances, and close to zero for artificial radioactive substances (Department for Business Energy and Industrial Strategy 2018). Therefore, a programme of surveillance into the distribution of important radionuclides is maintained using research vessels and other means of sampling.

The seawater surveys reported here also support international studies concerned with the quality status of coastal seas. The programme of radiological surveillance work provided the source data and, therefore, the means to monitor and assess progress in line with the UK’s commitments towards OSPAR’s 1998 Strategy for Radioactive Substances target for 2020 (part of the North-East Atlantic Environment Strategy adopted by OSPAR for the period 2010 to 2020), see Section 1.3 of this report for more details. The surveys also provide information that can be used to distinguish different sources of artificial radioactivity (for example, Kershaw & Baxter 1995) and to derive dispersion factors for nuclear sites (for example, Baxter & Camplin 1994). In addition, the distribution of radioactivity in seawater around the British Isles is a significant factor in determining the variation in individual exposures at coastal sites, as seafood is a major contribution to food chain doses.

The research vessel programme on radionuclide distribution currently comprises annual surveys of the Bristol Channel, western English Channel and biennial surveys of the Irish Sea and the North Sea. The results obtained in 2025 are given in Figure 8.6 to Figure 8.10 and are discussed in the text below.

Figure 8.6. Concentrations (Bq l^-1) of caesium-137 in surface water from the Irish Sea, September 2025. Figure generated with PyGMT v0.19.0 (Tian and others, 2026) and GMT v6.7.0 (Wessel and others, 2019).

Figure 8.7. Concentrations (Bq l^-1) of caesium-137 in surface water from the English Channel, March 2025. Figure generated with PyGMT v0.19.0 (Tian and others, 2026) and GMT v6.7.0 (Wessel and others, 2019).

Figure 8.8. Concentrations (Bq l^-1) of tritium in surface water from the Irish Sea, September 2025. Figure generated with PyGMT v0.19.0 (Tian and others, 2026) and GMT v6.7.0 (Wessel and others, 2019).

Figure 8.9. Concentrations (Bq l^-1) of tritium in surface water from the Bristol Channel, September 2025. Figure generated with PyGMT v0.19.0 ((Tian and others, 2026) and GMT v6.7.0 (Wessel and others, 2019).

Figure 8.10. Concentrations (Bq l^-1) of tritium in surface water from the English Channel, March 2025. Figure generated with PyGMT v0.19.0 (Tian and others, 2026) and GMT v6.7.0 (Wessel and others, 2019).

A seawater survey of the Irish Sea was carried out in 2025. As in previous surveys, a band of slightly higher concentrations of caesium‑137 was observed along the coast to the north and south of Sellafield, with levels generally decreasing with distance from the coast (Figure 8.6). The 2025 survey recorded concentrations of up to 0.04Bq l^-1 in the Irish Sea (in comparison with 0.04Bq l^-1 in the eastern Irish Sea in 2023). For the remainder of the Irish Sea, caesium‑137 concentrations were reported as ‘less than values’, or close to ‘less than values’ (0.02Bq l^-1). Overall, concentrations were similar to those reported in the previous Irish Sea survey in 2023 (Environment Agency and others, 2024). Caesium‑137 concentrations in the Irish Sea were only a very small percentage of those prevailing in the late 1970s, when discharges were substantially higher (typically up to 30Bq l^-1 Baxter, Camplin & AK 1992).

The predominant source of caesium‑137 to the Irish Sea is considered to be remobilisation into the water column from activity associated with seabed sediment (Hunt, Leonard & Hughes 2013). Discharges from Sellafield have decreased substantially since the commissioning of the Site Ion Exchange Effluent Plant waste treatment process in the mid‑1980s, and this has been reflected in a decrease in caesium‑137 concentrations in shoreline seawater at St Bees (Figure 8.13). In more recent years, the rate of decline of caesium‑137 concentrations over time has been decreasing at St Bees. Longer time series showing peak concentrations in the Irish Sea (Figure 8.11), and, with an associated time-lag, the North Sea are also shown in Figure 8.12.

Over several decades, the impact of discharges from the reprocessing plants at Sellafield and La Hague has been readily apparent, carried by the prevailing residual currents from the Irish Sea and the Channel, respectively (Povinec and others, 2003). Caesium-137 concentrations in the North Sea have tended to follow the temporal trends of the discharges, albeit with a time lag. The maximum discharge of caesium-137 occurred at Sellafield in 1975, with concentrations of caesium-137 of up to 0.5Bq l^-1 in the North Sea surface waters in the late 1970s. Due to significantly decreasing discharges after 1978, remobilisation of caesium-137 from contaminated sediments in the Irish Sea was considered to be the dominant source of water contamination for most of the North Sea (McCubbin and others, 2002).

In 2024, very low concentrations (up to 0.016Bq l^-1) were found throughout most of the North Sea survey area (Environment Agency and others, 2025). The few positively detected values were only slightly above those observed for global fallout levels in surface seawaters (0.0001 to 0.0028Bq l^-1, Povinec and others, 2005). The overall distribution in the North Sea is characteristic of that observed in previous surveys over the last decade, with generally positively detected values near the coast, due to the long-distance transfer, possibly from Sellafield or Chernobyl-derived activity. In 2024, there was no significant evidence of input of Chernobyl-derived caesium-137 from the Baltic (via the Skagerrak) close to the Norwegian Coast. Trends and observations of caesium-137 concentrations in the waters of the North Sea (and Irish Sea), over the period 1995 to 2015, have been published (Leonard and others, 2017).

Figure 8.11. Concentration of caesium-137, in Bq l^-1, in the Irish Sea, between 1965 and 2025

Figure 8.12. Concentration of caesium-137, in Bq l^-1, in the North Sea between 1965 and 2025

Figure 8.13. Concentration of caesium-137, in Bq l^-1, in shoreline seawater close to Sellafield at St. Bees

In 2025, caesium-137 concentrations were reported as ‘less than values’ (or close to the ‘less than value’) in the western English Channel (including those near the Channel Islands) and were not distinguishable from the background of fallout from nuclear weapons testing (Figure 8.7).

A full assessment of historic long-term trends of caesium-137 in surface waters of Northern European seas is provided elsewhere (Povinec and others, 2003).

Tritium concentrations in Irish Sea seawater in 2025 are shown in Figure 8.8, reported as ‘less than values’ (or close to the ‘less than value’). As expected, these are generally higher (by small amounts) than those observed in the North Sea in 2024 (Environment Agency and others, 2024) due to the influence of discharges from Sellafield and other nuclear licensed sites. As in previous Irish Sea surveys, tritium concentrations to the south and west of the Isle of Man, including along the coastline of Ireland, were mostly reported as below (or close to) a ‘less than value’. For comparison, the background concentration of tritium from natural and industrial sources (but excluding fallout from nuclear weapons testing) in seawater from the North Atlantic Ocean is estimated to be 0.05Bq l^-1 (Jean-Baptiste and others, 2018). In industrial activity, however, tritium is not normally removed from effluent prior to discharge, and locally elevated tritium concentrations in seawater of around 1 to 2 Bq l^-1 have been observed near nuclear sites (for example, Jean-Baptiste and others, 2018).

In the Bristol Channel, the combined effect of historical tritium discharges from the Maynard Centre, the former GE Healthcare Limited facility at Cardiff^{[footnote 9]}, and those from Berkeley, Oldbury, and Hinkley Point, is shown in Figure 8.9. Tritium concentrations in the Bristol Channel were low in 2025 (all reported at the limit of detection). Most results are reported as ‘less than values’ (or close to the ‘less than value’) in the vicinity of the Welsh coast. Overall, tritium concentrations were lower in the inner region of the Bristol Channel, in comparison to recent years. There is no evidence of tritium entering the Irish Sea from the combined effect of discharges from the former GE Healthcare Limited facility at Cardiff, Berkeley, Oldbury, and Hinkley Point. Discharges from the Pharmaron UK radiolabelling facility, in Cardiff, also provide a minor contribution of tritium to this area. Tritium concentrations in the western English Channel were all reported as below the ‘less than value’ (or close to the ‘less than value’) (Figure 8.10).

Technetium-99 concentrations in seawater have decreased following the substantial reduction in discharges resulting from discharge abatement. This followed substantial increases observed from 1994 to their most recent peak in 2003. The results of research cruises to study this radionuclide have been published (K. Leonard and others, 1997; K. S. Leonard and others 1997; McCubbin and others, 2002; Leonard and others 2004; Leonard and others, 2008) and an estimate of the total inventory residing in the sub-tidal sediments of the Irish Sea has also been published (Jenkinson and others, 2014). Trends in plutonium and americium concentrations in seawater of the Irish Sea have also been published (Leonard and others, 1999).

Full reviews of the quality status of the north Atlantic and a periodic evaluation of progress towards internationally agreed targets have been published by OSPAR (OSPAR 2000; OSPAR 2009; OSPAR 2010; OSPAR 2016). The fifth periodic evaluation covers both radioactive discharges from the nuclear and non-nuclear sectors and environmental concentrations and demonstrated that Contracting Parties successfully fulfilled the RSS objectives for the nuclear and non-nuclear sectors (OSPAR 2022).

Shoreline sampling was also carried out around the UK, as part of routine site and regional monitoring programmes. Much of the shoreline sampling was directed at establishing whether the impacts of discharges from individual sites are detectable. Where appropriate, these are reported in the relevant sections of this report, and the results are collated in Table 8.10. Most radionuclides are reported as ‘less than’ values. Tritium and caesium-137 concentrations remote from site discharge points are consistent with those in Figure 8.6 to Figure 8.10.

SEPA took a series of seawater samples near Uist. All radionuclides were reported as ‘less than’ (or close to the limit of detection). The results are presented in Table 8.11.

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Main Report Footnotes

1. The Environment Agency has an agreement with Natural Resources Wales (NRW) to undertake some specific activities on its behalf including radiological environmental monitoring and Radioactive Substances Regulation of nuclear sites in Wales. ↩

2. The application of BAT does not apply under Radioactive Substances (Modification of Enactments) Regulations (Northern Ireland) 2018 ↩

3. At some locations separate nuclear sites are situated adjacent to one another, for example some EDF Energy operated power stations have a neighbouring Nuclear Restoration Services decommissioning station. As these are operated by different employers, workers at one station are considered to be ’informed workers’ for the purpose of assessing direct radiation exposure to the other station. Doses to workers are considered differently to those for the public and therefore are not included in ‘total dose’ assessments. ↩

4. Natura 2000 is made up of sites designated as Special Areas of Conservation (SACs) and Special Protection Areas (SPAs). SACs and SPAs in the UK no longer form part of the EU’s Natura 2000 ecological network. The 2019 Regulations have created a national site network on land and at sea, including both the inshore and offshore marine areas in the UK. ↩

5. The reference to proprietary products in this report should not be construed as an official endorsement of those products, nor is any criticism implied of similar products which have not been mentioned. ↩ ↩²

6. Values are rounded to 2 significant figures, or 3 decimal places, depending on their magnitude. ↩

7. Contributions are rounded to the nearest percent. ↩

8. ‘Particles and objects’ are terms used which encompass discrete radioactive items which can range in radioactivity concentration, size and origin. ‘Particles’ include radioactive scale, fragments of irradiated nuclear fuel and incinerated waste materials (less than 2mm in diameter). ‘Objects’ are larger radioactive artefacts and stones which have radioactive contamination on their surface and are larger than 2 mm in size. ↩

9. GE Healthcare ceased manufacturing tritium and carbon-14 radiolabelled compounds at its premises, the Maynard Centre, in Cardiff in 2009 and 2010, respectively. Its custom radiolabelling division was acquired by Quotient Bioresearch (Radiochemicals) Ltd in 2010, and subsequently by Pharmaron UK Ltd in 2017. This operation is located at a new premises in Cardiff under a non-nuclear permit, albeit at lower levels compared to the historic discharges from the Maynard Centre. ↩ ↩² ↩³

10. The FEPA Order was made in 1997 following the discovery of fragments of irradiated nuclear fuel on the seabed near Dounreay, by United Kingdom atomic energy authority (UKAEA), and prohibits the collection of seafoods within a 2km radius of the discharge pipeline. ↩

11. DPAG was set up in 2000, and PRAG(D) thereafter, to provide independent advice to SEPA and United Kingdom atomic energy authority (UKAEA) on issues relating to the Dounreay fragments. ↩