Form

How to apply for a radioactive substances activity permit for large-scale fusion using Part RSR-B8

Published 14 September 2026

Applies to England

You must read this guidance carefully before you fill in the form RSR-B8. We recommend that you consult a Radioactive Waste Advisor (RWA) before completing this form.

Complete form RSR‐B8 if:

• you are applying for a new bespoke permit, or variation to an existing permit, for a radioactive substances activity involving ‘large-scale’ fusion activities using unsealed sources
• you currently have a radioactive substances activity permit and are scaling-up your fusion activities to ‘large-scale’, and your Environment Agency regulator tells you to use this form

For the purposes of this form, ‘large-scale’ means a fusion device that is being designed to generate, or test the feasibility of generating, usable net energy from the fusion of atomic nuclei. This means the activity which requires a permit has gone beyond the stage where you are testing principles of fusion but are now developing a device that is intended to produce net energy and generate electricity. Your device may not be able to do this yet, it may still be a pilot plant, but you are working towards this point.

For security reasons, applications for radioactive substances activities involving sealed sources must be made separately using form RSR‐B2.

1. Your application

1.1 Part RSR-B8 is used for permits for large-scale fusion operations. If you’re not sure if your application is for a ‘large-scale’ fusion activity, please contact us. Is this an application for a new permit or a variation? For variations, only fill in the sections for which you are proposing new or changed information. For a new permit, complete the whole form.

1.2 Tell us if you have recently made, or you intend to make, an application for an environmental permit to operate a regulated facility, other than a radioactive substances activity, on the premises. This will enable us to coordinate our determination work.

2. What do you want to do?

2.1 Radioactive substances activities

Tick the relevant boxes to show which radioactive substances activities you are undertaking.

2.2 Technical description

We ask you about your radioactive waste arisings more specifically in Question 4. For this question, only provide summary, high-level information about your waste.

If you are applying for a variation, you only have to describe the changes that you want to make to your activity.

Provide a technical description of your activities. Your description should include:

• the overall function of the facility in which you carry out the radioactive substances activities
• identification of the systems, structures, components and processes required for the keeping and use of radioactive substances and have a bearing on radioactive waste generation, accumulation (storage), treatment, abatement, measurement, assessment and disposal
• how radioactive material will be managed and radioactive wastes will arise, be managed, accumulated (stored) and disposed of throughout the facility’s lifecycle

Your description of how radioactive material and radioactive wastes will be managed throughout the facility’s lifecycle should include:

• sources of radioactivity
• where and how radioactive materials will be used or generated, on the premises, including where they will be stored when not in use
• how you will prevent leaks and escapes of radioactive substances, including waste
• matters which affect gaseous, aqueous and other radioactive wastes arising
• discharge points for gaseous radioactive wastes and discharge routes (see note 1) for aqueous radioactive wastes (including any minor discharge points such as building or tank vents)
• any significant non‐radiological hazards associated with your radioactive wastes
• disposal routes for other non-radioactive wastes (see note 2)

If your facility is experimental, you should provide us with a timeline of your proposed experiments that will use radioactive substances or that could generate radioactive waste, including by activation. We recognise that your timeline might have significant uncertainties, but we expect you to update this timeline during your operational period.

Note 1: We strongly advise you to talk to us before completing this form if you are proposing to dispose of aqueous radioactive waste into the ground (for example, a discharge to a soakaway that is not directly connected to the saturated zone). We will not permit direct inputs of liquid radioactive waste to groundwater (for example, a discharge to a borehole that extends down to or into the water table).

Note 2: Where you intend to dispose of radioactive waste by transfer to another person, you should provide evidence that either:

• you have contractual arrangements in place to do this
• where disposal may not take place for some time, such contractual arrangements can be put in place

2.3 Management system and organisational capability

If you are applying for a variation, you only have to describe the changes in your management system and organisational capability.

See our guidance on how to develop a management system and keep it up to date so that you can carry out activities under an environmental permit. For additional guidance on developing and maintaining a management system for an open (unsealed) source radioactive substances activity permit, including receipt, accumulation and disposal of radioactive waste, see our How to comply guidance.

Provide a description of your management system and organisational capability, and how they will change over time as your activities change. Organisational capability means that you can demonstrate that your organisational structure, staffing and competencies (including decision-making and governance) are sufficient to maintain compliance with a permit issued to you throughout the lifecycle of your activity. This demonstration also provides the foundation from which organisational changes can be assessed against relevant permit conditions.

If you are applying for a permit in advance of undertaking any activities involving radioactive substances, your management system should be commensurate with the activities you are undertaking at the time of application. You must also describe how your management system and organisational capability will develop over time up until the point at which you start using radioactive substances on your premises.

If your plant is experimental, you should describe how your programme of experiments will affect your management system and organisation capability. We recognise that there may be uncertainties around your experimental programme at this time. We will expect you to resolve these uncertainties during your operational period and be able to demonstrate that your management system and organisational capability are sufficient to comply with your permit conditions at all times.

For all applicants, you should describe:

• how you manage generating, ordering, receiving, using, storing and disposing of radioactive substances
• how you prevent, minimise, characterise, segregate, accumulate (store), dispose and, if required, receive radioactive waste (see note 3)
• how you manage design control and modification of your plant
• how you optimise your operations to ensure that radiation doses to the public and wildlife are As Low As Reasonably Practicable (ALARA), including how you justify, identify, assure and accept into service the Best Available Techniques (BAT) for processes, systems and equipment associated with the generation and management of discharges or disposals of radioactive waste
• how you categorise, accept into service and maintain structures, systems and components with an environmental protection function
• your organisational capability – you must have an organisation with the capability to comply with your permit conditions at all times, including decision-making and governance capabilities
• how you prevent and respond to incidents and accidents that could lead to pollution or not being able to comply with your permit (see note 4)

Note 3: We ask you about your radioactive wastes more specifically in Question 4, so for this question only provide high-level information about how you will manage your radioactive waste.

Note 4: We have specific guidance on Flood risks for non-nuclear users of radioactive substances.

2.4 Decommissioning

If you are applying for a variation, you only have to describe how the changes you’re looking for will affect your decommissioning plan.

We expect operators to take into account the eventual decommissioning of the site during its design, construction and early operation. See our additional guidance on planning for decommissioning.

You must provide us with a plan for decommissioning your facility. Your plan may contain significant uncertainties at this time, but we will expect you to keep your decommissioning plan updated and resolve uncertainties throughout your operational period. This is so that you have a robust decommissioning plan in place by the time you want to cease operations, dismantle your facility and surrender your permit. We will periodically inspect your decommissioning plan to ensure that it is being updated.

Surrender

You should describe how you expect to bring the site to a condition that will enable your permit to be surrendered when all planned work with radioactive substances has ceased. You should show that you have considered the standards that will ultimately have to be met for the site to be released from regulation. For fusion sites, these standards are that both:

• pollution resulting from the operation of the regulated facility has been avoided
• the site of the regulated facility has been returned to a satisfactory state, having regard to the state of the site before the facility was put into operation

You will need to keep good records about your radioactive substances activities to support your application for surrender. You should plan to make sure you have the right information available to surrender your permit. Your planning should take into account of our guidance on permit surrender.

3. What radioactive material do you want to keep and/or use on your premises?

You must apply the principles of BAT to ensure that you hold only the types and quantities of radioactive material that are reasonably necessary for you to carry out your activities.

3.1 Radioactive materials

List all radionuclides that you want to keep and use on these premises in order, starting with the highest‐activity material and finishing with the lowest‐activity material. List individually radionuclides that dominate your usage together with the maximum activity, in becquerels (Bq), of each radionuclide.

For other radionuclides you might use on your site, for example, in research labs where you use small amounts (for example, a few megabecquerels) of similar radionuclides, you can opt to apply for them as a group. This will give you flexibility. In these cases, we will only include the following unsealed source groups:

• total alpha‐emitting radionuclides
• carbon‐14, tritium
• total beta/gamma‐emitting radionuclides
• tritium, carbon‐14, phosphorus‐32, sulphur‐35, iodine‐125
• total positron‐emitting radionuclides
• thorium natural
• iodine radionuclides
• total radionuclides
• uranium – depleted or natural
• uranium – enriched

Maximum activity

This refers to the total activity of the specified radionuclide to be held on the premises at any one time.

Using becquerels

You should list activity in SI units (becquerels). Write the prefix kilo‐, mega‐, giga‐, and so on, clearly (in full) to minimise the risk of error. If applicable, for natural thorium and natural and depleted uranium give their mass in kilograms.

Rounding up substances of nominal activity

If you use radioactive material of nominal activity (particularly with radionuclides of short half‐life), you may round up the figure to ensure you do not risk exceeding your permitted limit (even temporarily). If you do round up a figure, make sure you say how and where you have done this.

3.2 and 3.3 Details of the materials and how you intend to use them

It is important that you use your application to tell us why you want to hold radioactive materials, and how you will use them. Include radioactive materials that you reasonably expect to hold at any one time over the next 3 to 5 years. You need not include materials you are confident you can hold under the terms of an exemption.

We use the information you give us to:

• consider whether the use of radioactive material is appropriate for the activity proposed, for example, could you use a non-radioactive surrogate
• specify those uses in the permit
• set out any special conditions for your premises

4. What radioactive waste do you want to accumulate (store), or dispose of to the environment or transfer to another site for treatment and/or disposal?

4.1 Waste Management Plan (WMP)

See our additional guidance about the purpose and production of a WMP.

Describe how you will manage the production, accumulation and disposal of radioactive waste to ensure that radiation doses to the public from your waste disposals are optimised so that they are ALARA and that wildlife are protected. You should identify and justify the techniques you are proposing as BAT.

In identifying BAT, you should address both the technology you use and the way your facility is designed, built, maintained, operated and dismantled. In justifying techniques as BAT and demonstrating optimisation, you will need to address all of the following, in respect of radioactive wastes arising throughout the lifetime of the facility:

• preventing and minimising (in terms of radioactivity) the creation of radioactive waste during operations, decommissioning and dismantling
• minimising (in terms of radioactivity) discharges of gaseous and aqueous radioactive wastes
• minimising the impact of those discharges on the public, and adequately protecting other species
• minimising (in terms of mass or volume) solid and non‐aqueous liquid radioactive wastes
• minimising the time over which radioactive wastes are accumulated (stored)
• how the non‐radiological hazards of the radioactive waste (for example, asbestos fibres or chemical toxicity) will be managed
• how you will manage radioactive material while it is kept and waste while it is stored (accumulated), in order to prevent its escape, contamination of other materials and the generation of secondary radioactive wastes
• selecting optimal disposal routes, taking account of the waste hierarchy and the proximity principle, for those wastes
• the suitability for disposal of any radioactive wastes you create for which there is no currently available disposal route, for example higher activity wastes (HAW) that require disposal at a Geological Disposal Facility, and how you will manage them in the interim so as to ensure their ultimate disposal whilst minimising environmental impact (see note 5)

If you are proposing to dispose of aqueous radioactive waste into the ground, you will also need to explain how you will take all necessary and reasonable measures to:

• prevent the input of radioactive waste and any other hazardous substances to groundwater
• limit the input of non‐hazardous pollutants to groundwater to ensure that such inputs don’t pollute groundwater – see our guidance on groundwater risk assessments for your environmental permit

Further guidance on optimisation is provided in RSR: Principles of optimisation in the management and disposal of radioactive waste.

Use your WMP to also provide quantitative estimates, during normal operation, of:

• discharges of gaseous and aqueous radioactive wastes (further detail about discharges are required in answer to questions 4.2 and 4.3)
• arisings of combustible radioactive waste and disposals by on‐site or off‐site incineration
• arisings of other radioactive wastes, by category and disposal route (if any)

Note 5: We expect you to provide analysis of the disposability of HAW and of the impact of their accumulation (storage) as part of your radioactive waste management arrangements. The analyses and their conclusions should demonstrate optimisation over the life cycle of the waste. For further guidance see The management of HAW on nuclear licensed sites, which must be applied proportionately and in consultation with the Environment Agency.

4.2 and 4.3 Discharge limits

For gaseous and aqueous radioactive wastes, you should estimate your monthly discharges:

• on an individual radionuclide basis for significant radionuclides
• on a group basis (for example, ‘total alpha’ or ‘total beta’) for other radionuclides
• through each discharge point and discharge route (as identified in your ‘Technical description’ provided in answer to question 2.2)

‘Significant radionuclides’ are those which:

• are significant in terms of radiological impact for the public – this means the dose to the most exposed group at the proposed limit exceeds 1 μSv per year (see note 6) – or non‐human species but only where the impact on reference organisms from the discharges of all radionuclides/groups at the proposed limits exceeds 40 μGy/hour
• are significant in terms of the quantity of radioactivity discharged – this means that they are numerically high, close to or exceeding 1 TBq per year
• have long half‐lives, may persist or accumulate (or both) in the environment, and may contribute significantly to collective dose (this only needs to be considered where the 500‐year collective dose from the discharges of all radionuclides at the proposed limits exceeds 1 man‐sievert per year)
• constrained under national or international agreements or is of concern internationally
• are significant indicators of facility performance and process control

Your estimates should use the radionuclides and groups of radionuclides listed in the RSR pollution inventory (PI) reporting form as far as practicable.

You may additionally propose ‘campaign’ limits, where appropriate. For example, if your operations (and consequent discharges) are cyclical or on a batch basis or are a series of tests, you might want to propose limits for a complete cycle, set of experiments or for one or more batches.

Your estimates of disposals should clearly show the contribution of each constituent aspect of normal operations, including:

• routine operation (that is, typically, the design basis or ‘flowsheet design’ and the minimum level of disposals)
• start‐up and shutdown
• maintenance and testing
• infrequent but necessary aspects of operation, for example, plant wash‐out; and the foreseeable, undesired deviations from planned operation (based on a fault analysis) consistent with the use of BAT

You should support your estimates with performance data from similar facilities and explain, if possible, how changes in design or operation from those facilities affect the expected disposals.

For combustible and other radioactive wastes, you should estimate the annual arisings and disposals during operation. You should also give an indication of the likely arisings during decommissioning. You should identify wastes in terms of their category, for example intermediate level waste (ILW) or low-level waste (LLW), physico‐chemical characteristics and proposed disposal route (if any). Quantification should be in terms of activity of key individual radionuclides and overall groupings of radionuclides (for example, total alpha), together with mass or volume (or both).

Where your radioactive wastes contain significant non‐radiological hazards (for example, asbestos fibres or chemical toxicity) you should describe what these are and quantify the non‐radiological content of the radioactive waste as appropriate. This is relevant even if the radioactive waste is only being disposed of by transfer to another site.

Note 6: The RSR PI reporting thresholds may be used as an initial screen since these relate to about 1 μSv per year under assumed conditions. This can be refined by the radiological assessments undertaken in relation to question 6.2.

4.4 Transfer of radioactive waste

Explain the arrangements you have made to transfer your radioactive waste to another operator. You should describe:

• the waste types
• how and why they arise
• details of the transferee
• what you expect the transferee to do with it

You do not need to include radioactive waste that you intend to dispose of under an exemption. Check the guidance on scope of and exemptions from the radioactive substances legislation in England, Wales and Northern Ireland.

You should give the specified information for each radionuclide or group of radionuclides you wish to transfer.

You should give details of your plans to transfer organic or aqueous liquid radioactive waste, if any.

You must have in place contracts with a waste disposal or storage company (or companies) to dispose of all your radioactive waste.

You should provide evidence that you have contractual arrangements in place to do this or, where disposal may not take place for some time, that such contractual arrangements can be put in place. This may take the form of a letter of agreement in principle or contract with a waste recipient to accept waste.

We include in permits for operators that receive waste for final disposal a condition requiring them to inform their local authority before they first receive waste from any new consignor. Under this condition the operator of a disposal site will inform the local authority of the origin and nature of the radioactive waste before the first waste is received from a new consignor.

You should describe contingency arrangements should your planned transfer routes for liquid or solid waste become unavailable. You should state your plans, including what will happen to waste already created or held.

4.5 Accumulation of radioactive waste

You should provide details of the radioactive wastes you want to accumulate (store) in your WMP. Specify the significant radionuclides involved.

Give the maximum activity and volume of the relevant waste types (solid, gaseous, aqueous or organic liquid).

Additionally, you should explain the following:

• why you plan to accumulate radioactive waste – explain why you want to accumulate waste from unsealed sources and why accumulation represents an optimised solution
• how you have used BAT to eliminate or reduce the amount of radioactive waste you accumulate as far as is practical
• how you will apply BAT during the period of accumulation to prevent leakage and escape of radioactive waste and otherwise ensure that doses to the public and wildlife are ALARA
• how you plan to accumulate radioactive waste – explain what facilities and controls you will use to accumulate waste from unsealed sources – give details of what controls you will use to help keep the radioactive waste safe before you dispose of it, for example, security, fire alarms, procedures for preventing fires and segregation of different types of radioactive waste
• how long you plan to accumulate radioactive waste for – different radionuclides or types of radioactive waste may need different periods
• how you will measure the activity of all the types of radioactive waste – outline the principal steps in the estimation or analysis of waste from unsealed sources, including type of radiation detection, for example, liquid scintillation counter
• the non-radiological chemical and physical characteristics of the radioactive waste – describe the types of waste from unsealed sources and what they are made from or composed of

5. Receipt of radioactive waste

5.1 Receiving radioactive waste

You should provide details of the radioactive wastes you want to receive in your WMP – see Question 4.1. Provide details of the origin, nature and quantity of each radioactive waste stream to be accepted onto the premises, and how you will manage and dispose of it. Ensure that waste you want to receive is reflected in the accumulation limits you apply for – see Question 4.5.

For each radioactive waste stream you plan to receive, tell us:

• where the waste will come from (you may only be able to do this in general terms)
• its physico‐chemical properties
• how much of it (mass or volume and radioactivity content) you will receive and over what period
• how you will treat or store it
• how and when you will dispose of i.

5.2 Waste from NAIR or Radsafe

Tick the relevant box as to whether you are participating in the National Arrangements for Incidents involving Radioactivity (NAIR) or Radsafe schemes. You do not have to provide any details in this application about waste you may receive because of your participation in the NAIR or in a Radsafe incident response.

6. What impact will your disposals of radioactive waste have on the public and wildlife?

6.1 Monitoring

6.1.1 Provide a description of the sampling arrangements, techniques and systems for measurement and assessment of discharges and disposals of radioactive waste. Your description should:

• include details of your in‐process monitoring arrangements, as well as those for your final discharges and disposals
• demonstrate your proposals represent the BAT for monitoring
• confirm the sensitivity is sufficient to readily demonstrate compliance with the proposed limits

6.1.2 Provide a description of your environmental monitoring programme. You should provide your proposed environmental monitoring programme for both:

• the operational phase of your facility
• establishing a pre‐operational baseline (or provide the results of this if already completed)

Your operational programme should take account of our guidance Environmental radiological monitoring: planning and implementing your programme.

6.1.3 Provide a description of the equipment and procedures you will use to measure and assess the exposure of members of the public and radioactive contamination of the environment from your waste disposal activities throughout the lifecycle of your activities. Your description should be commensurate with the stage of development of your organisation. Where you have uncertainties about how you will do this, for example you may be uncertain what tests or experiments you might perform or when you might decommission, you should identify these uncertainties and provide a plan to resolve them.

6.2 Radiological assessment

Your radiological dose assessment should include:

• annual dose to most exposed members of the public for aqueous discharges
• annual dose to most exposed members of the public for gaseous discharges (identifying separately the dose associated with on‐site incineration where applicable)
• annual dose to most exposed members of the public through the groundwater pathway, if you are proposing to dispose of aqueous radioactive waste into the ground
• annual dose to the most exposed members of the public for all discharges from the facility
• annual dose from direct radiation to the most exposed member of the public
• annual dose to the representative person for the facility
• potential short‐term doses, including via the food chain, based on the maximum anticipated short-term discharges from the facility in normal operation
• a comparison of the calculated doses with the relevant dose constraints (taking account of any historical and future discharges from other facilities in the locality where appropriate)
• an assessment of whether the build‐up of radionuclides in the local environment of the facility, based on the anticipated lifetime discharges, might have the potential to prejudice legitimate users or uses of the land or sea
• collective dose, truncated at 500 years, to the UK, European and world populations

You should tell us which model (or models) you used to calculate these doses and why they are appropriate, and set out all the data and assumptions (with reasoning) that you used as input into the models including:

• radionuclide composition of each discharge
• chemical form of each radionuclide discharges
• gaseous discharge points details (including location, heights, effective heights and volumetric flow rates)
• aqueous waste discharge points details
• proportions of discharges made via each discharge point (including incinerators)
• data used to estimate incinerator discharges (including quantities of waste to be incinerated, expected radionuclide composition and concentrations, retention factors for any abatement provided)
• hydrographic data (mean volumetric flow for inland water courses or volumetric exchange rate for estuaries or coasts)
• location of dose receptor points
• weather data
• deposition velocities, washout coefficients and surface roughness factors
• dose per unit intake factors
• food consumption rates
• habits data for the representative person
• nearest food production location
• nearest habitation
• hydrogeological and soil data, if you are proposing to dispose of radioactive waste into the ground

Your assessment should take account of the principles and guidance in the Principles for the assessment of prospective public doses arising from authorised discharges of radioactive waste to the environment.

Wildlife

You should assess the dose‐rates to reference organisms that result from your proposed discharges (including any indirect input to groundwater you propose). An appropriate range of reference organisms for freshwater, marine and terrestrial ecosystems is included in the ERICA tool.

You should calculate worst‐case dose‐rates by assuming the presence of the reference organisms for the relevant ecosystem at the position of maximum environmental concentration due to discharges (usually, close to the site boundary for the terrestrial ecosystem, and close to the point of discharge for aquatic ecosystems).

Tell us which model you used to calculate these dose‐rates and why it is appropriate, and set out all the data and assumptions (with reasoning) you used as input into the model, where not already covered in question

You should identify the designated wildlife sites (National Network Sites and Sites of Special Scientific Interest) likely to be impacted by the discharges and explain your selection of the ERICA reference organisms and how they represent species of interest around the site.

The Environment Agency will:

• assess the combined impact of discharges, from your and all other relevant permitted sites, on each potentially affected designated site
• compare those combined impacts with the 40 µGy/hour guideline value

An appropriate tool for assessing impacts on non‐human species is available on the ERICA website. ERICA was a research project under the EC Euratom 6th Framework programme. The ERICA tools cannot assess dose rates from noble gases (activated air products) and for these substances the Ar‐Kr‐Xe dose calculator can be downloaded from the Centre for Ecology and Hydrology (CEH).