Dounreay 2023
Published 3 April 2023
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Your guide to Scotland’s centre of excellence in nuclear decommissioning
Britain emerged from the Second World War intent on harnessing nuclear energy to power its recovery. But uranium was scarce and its use prioritised for weapons production, so the country launched one of its most visionary scientific experiments – to research and develop a new type of power station that would create more fuel than it consumed. Dounreay was chosen as the test site for this new technology of fast breeder nuclear reactors. Over the next 40 years, scientists and engineers proved that plutonium could be harvested from a reactor and recovered in adjacent chemical works to create new fuel to generate electricity.
As the 20th century drew to a close, and uranium prices continued to fall, the economics of electricity from plutonium became uncompetitive and the UK Government withdrew from the technology.
Today, after leading the world for 4 decades in research and development of nuclear technology, Dounreay is again at the forefront of science and engineering – this time in the skills and innovation needed to dismantle one of the most complex and hazardous legacies of the 20th century. Dounreay today is a site of major construction, demolition and waste management. The experimental facilities are being cleaned out and knocked down, and the environment is being made safe for future generations.
| Year | Event |
| 1954 | UK Government selects wartime airfield at Dounreay as site for fast reactor research and development |
| 1955 | UK Atomic Energy Authority begins construction |
| 1955 | Craft apprentice training scheme starts |
| 1955 | UKAEA starts building housing estate in Thurso |
| 1956 | Ormlie Lodge staff hostel opens |
| 1957 | Nuclear reaction takes place for first time in criticality test cell |
| 1957 | Royal Navy announces submarine reactor test site named Vulcan |
| 1957 | Visits by HRH The Queen Mother and The Duke of Edinburgh |
| 1958 | Materials Test Reactor goes critical |
| 1958 | Fuel reprocessing begins |
| 1959 | Experimental Fast Reactor goes critical |
| 1962 | First electricity exported to National Grid |
| 1966 | Construction begins of Prototype Fast Reactor |
| 1969 | Materials Test Reactor shuts down |
| 1974 | Prototype Fast Reactor goes critical |
| 1977 | Experimental Fast Reactor shuts down |
| 1977 | Explosion in underground waste shaft |
| 1983 | Radioactive particles discovered on beaches |
| 1986 | BNFL and UKAEA announce plan to build European Demonstration Reprocessing Plan |
| 1988 | UK Government announces withdrawal from fast reactor technology |
| 1994 | Prototype Fast Reactor shuts down |
| 1996 | Fuel reprocessing stops |
| 1998 | Safety audit by regulators identifies 143 recommendations for improvement |
| 2000 | UK Atomic Energy Authority publishes site closure plan |
| 2004 | Fuel fabrication stops |
| 2007/8 | Nuclear Decommissioning Authority inherits site and Dounreay Site Restoration Ltd becomes its operator |
| 2012 | Management contracted out to Babcock consortium |
| 2015 | Removal of plutonium and uranium begins |
| 2021 | Nuclear Decommissioning Authority takes management in-house |
| 2023 | Dounreay becomes a division of Magnox Ltd |
Who’s who
Dounreay is owned by the Nuclear Decommissioning Authority, a non-departmental public body of the UK Government responsible for 17 legacy sites in the UK. Its funding comes from the UK Treasury via the Department for Business, Energy and Industrial Strategy. Since April 2023, Dounreay has been a division of Magnox Ltd, a wholly-owned subsidiary of the NDA. Dounreay’s turnover of approximately £200 million a year comes from the NDA.
Dounreay is regulated by:
- The Office for Nuclear Regulation, for nuclear safety and, from 2021, the safeguard functions of Euratom
- The Scottish Environment Protection Agency, for the disposal of radioactive and other waste
- The Highland Council, for land use and planning.
The Civil Nuclear Constabulary is responsible for the armed protection of the site and its nuclear material
The legacy
About 180 separate facilities were built on 135 acres of land at Dounreay. About 50 of these had a history of working with nuclear materials. The facilities covered every aspect of the nuclear fuel cycle – from fuel fabrication and reactors through to plants for the chemical separation of spent fuel, recovery of plutonium and uranium, and disposal and storage of waste. Each is now in the process of being cleaned out and dismantled. Their operation also left an environmental legacy – soil polluted with radioactive and chemical waste and radioactive particles on the seabed that occasionally wash up on nearby beaches.
Decommissioning
The objective of decommissioning is to reduce and remove the radiological, chemical and industrial hazards and leave the site in a condition that is safe for future generations. Decommissioning generates a variety of radioactive, chemical and industrial wastes and these must be stored or disposed of in a way that protects future generations from harm, too. The first site-wide decommissioning plan published in 2000 envisaged a 60-year programme of work. Innovation, new technology and experience made it possible to accelerate these timescales. Dates for the completion of decommissioning – known as the interim end state, when the hazards have been reduced or eliminated, and the site enters long-term care and maintenance – are being reviewed
The projects
Decommissioning a site as complex as Dounreay requires an integrated plan, showing the work needed to dismantle each facility, the routes for managing the different types of waste this creates the regulatory requirements – all of it matched to a wide range of professional, technical and clerical skills.
The programme can be broken down into the following:
Reactors
Dounreay Materials Test Reactor
All fuel and coolant were removed after closure. Decommissioning is now in the nal stage of strip-out and demolition.
Dounreay Fast Reactor
All fuel was removed after closure. Removal of the last of the breeder material resumed after a hiatus and is now being transferred to Sellafield. Sodium-potassium liquid metal coolant was destroyed, leaving residues to be tackled.
Once the major radiological and chemical hazards have been removed, the reactor can be dismantled.
Prototype Fast Reactor
All fuel and breeder material were removed after closure. The bulk of its liquid metal sodium coolant has been destroyed.
Once the residual coolant has been removed and destroyed, the reactor can be dismantled.
Fuel Cycle Area
Facilities used in the separation of spent fuel and recovery of its uranium and plutonium are at different stages of clean-out and decommissioning. Underground storage facilities for high-active liquor from spent fuel reprocessing are being emptied to
Nuclear materials
The site’s inventory of unirradiated plutonium and highly-enriched uranium was removed between 2015 and 2019. Breeder material continues to be removed from the Dounreay Fast Reactor and transferred to Sellaeld. Irradiated spent fuel is also scheduled to leave the site.
Legacy waste facilities
A 65 metre deep shaft was used historically for the disposal of solid highactive waste and was succeeded by a near-surface silo. Preparations to empty both are at an advanced stage. Solid low-active waste was disposed of in a series of shallow pits. Preparations are at an advanced stage to retrieve this waste. High-active liquor from the reprocessing of spent fuel was stored in underground tanks. These will be decommissioned once the contents are removed and solidified for above ground storage as high-active waste.
Solid low-active waste was disposed of in a series of shallow pits. Preparations are at an advanced stage to retrieve this waste.
Radioactive waste Decommissioning generates large quantities of scrap and other materials that can be recycled. But some of this is contaminated with radioactivity and must be managed as radioactive waste in accordance with the policy of the Scottish Government.
High-active waste is conditioned in cement and stored in containers in above-ground storage facilities at the site.
Low-active waste is compacted, cemented in containers, and sent for disposal to a series of shallow engineered vaults adjacent to the site.
Decommissioning also generates gas and liquors containing low levels of radioactivity. This waste is not stored and can be discharged to sea or air under a formal authorisation granted by the Scottish Environment Protection Agency. Monitoring of the environment around Dounreay provides assurance these discharges do not harm people or the environment.
Particles in the marine environment
Radioactive swarf from the historic dismantling of spent fuel is known to have entered the site’s effluent system prior to 1984 and was discharged to sea. The seabed around the disused outlet was cleaned up between 2008 and 2012. Monitoring of local beaches continues to detect radioactive particles that are a legacy of these discharges.
Interim end state
This is the time when all the major hazards have been reduced or eliminated, the historic facilities have been decommissioned and the site and the environment is in a safe state for future generations. This will be followed by a period of care and maintenance that will endure for a further 300 years.
Beyond Dounreay
Dounreay employs approximately 1500 people directly. Its annual spend of some £200 million a year generates approximately 10% of the GDP of the North Highlands. Staffing levels and spending will decline as more of the hazards are reduced and removed. Some workers will see out their careers at Dounreay and others will transition to new roles and other sectors. An important part of the decommissioning programme is supporting staff to plan their futures beyond decommissioning and supporting the community to diversify its economic base.
The site does this in 2 ways:
- Helping staff adapt to the changing profile of the work through reskilling and transition to new employment opportunities
- Investing in major infrastructure projects identified by a local regeneration partnership as essential to the diversification of the area’s economy
At a glance
- 678 acreages owned by the Nuclear Decommissioning Authority at Dounreay
- 135 acreages of the licensed nuclear site
- 1500 size of the workforce
- 300 number of facilities to be removed
- 50 number of facilities with a history of radioactive use
- 73 number of operational facilities 5 number of reactors built at Dounreay and Vulcan