The UK currently operates 4 Magnox Reactors, 14 Advanced Gas Cooled Reactors (AGR) and 1 PWR at 11 sites, generating 20% of national electricity requirements [World Nuclear Association 2010]. Both Magnox reactors at Bradwell, in Essex, were shut down in 2002, whilst the 4 Magnox reactors at Calder Hall in Cumbria, the first commercial reactors in the world, ceased operation in 2003, followed by another 4 at Chapelcross in NW England in 2004 and 2 each at Dungeness in Kent and Sizewell in Suffolk at the end of December 2006. A number of research reactors are also in operation, and several are undergoing decommissioning.

In July 2004 a new Energy Act received Royal Assent. Under the new provisions, which also deal with alternative energy sources, a new body, called the ‘Nuclear Decommissioning Authority (NDA)’, was established to take ownership of all decommissioning sites and of the existing Magnox reactor sites. It became operational in April 2005. The NDA issued a Draft Strategy in December 2005, following a public consultation period. The Strategy has been formally approved by government and was published on 30th March 2006. The NDA estimates that total costs for decommissioning in the UK could approach £70 billion.

The NDA has assumed all of the liabilities currently managed by BNFL, UKAEA and others, including the legacy wastes from all BNFL’s activities at Sellafield and elsewhere, UKAEA’s activities at Dounreay and elsewhere, as well as those associated with the Magnox reactors operated by Magnox North and Magnox South, now owned by Energy Solutions as PBO. It is not responsible for those liabilities that are currently managed by the Ministry of Defence.

Following a 'competition' for ownership of the site operator and licence holder (SLC) at Sellafield (known as Sellafield Ltd), the company is now owned by Nuclear Management Partners as so-called Parent Body Organisation (PBO).

A shallow land disposal site for LLW has been operated at Drigg by BNFL since the 1960s. The proposed development by UK NIREX of a new facility at Sellafield in Cumbria was refused in 1997 after a public inquiry and new concepts must now be drawn up. A new LLW policy document was launched in March 2007.

Spent fuel is stored on site at power plants in pools then shipped to Sellafield for reprocessing and longer term storage. Current plans envisage a cessation of reprocessing by around 2017.

A national consultation began in 2001 to address methods for management of all solid, long-lived radioactive wastes. A new independent committee was set up to design the next stage of the consultation process, examine available waste management options and recommend a preferred one to government.

The group, known as the Committee on Radioactive Waste Management or CoRWM, comprised 12 members appointed from a shortlist of interested applicants, held its first meeting in November 2003. CoRWM published its final report on the future management of long-lived wastes in the United Kingdom on 31st July 2006. It recommended that deep geological disposal is the best available approach in terms of safety and security (the two issues of most importance to the public). In CoRWM's view, a repository should be sited by means of a partnership arrangement with a voluntary, willing, community, which would be compensated for its participation. In the meantime, CoRWM believed that a robust programme of interim storage is needed to safeguard the waste for 100 years or more, in case of delay or failure in a repository programme. CoRWM also called for the immediate creation of an oversight body to begin the process of implementation.

On 25th October 2006 the government confirmed that long-lived radioactive wastes will be disposed of in a deep geological repository as proposed, accepting CoRWM's recommendations for implementation, subject to a short public review. It gave responsibility for developing a programme to implement the strategy to the NDA which subsequently absorbed the functions of UK Nirex into the NDA and wound up the company. A new Radioactive Waste Management Directorate (RWMD) was established. A reconstituted CoRWM has been formed, with revised Terms of Reference, to advise government on all radioactive-waste related issues, thereby replacing the Radioactive Waste Management Advisory Committee (RWMAC). It held its first meeting in late November 2007.

A White Paper was published on 12 June 2008, detailing the volunteer process that will be followed and taking account of issues raised in the consultation. Communities were invited initially to 'express an interest' in taking part. If they can convince government that there is sufficient local support, the local decision making body (normally a district or county council) can make a formal 'decision to participate', provided an initial screening process, using a range of criteria, has determined that any or all of the volunteer communities are suitable to go forward to later siting stages. Communities will be supported financially to take part and any that pass beyond the initial screening stage will be encouraged to form partnerships with the Nuclear Decommissioning Authority and involve all local interests. The Scottish government declined to support the policy of deep disposal, calling instead for long term storage at the site of production. It issued its own policy document in January 2010.

In June 2008, Copeland Borough Council, which includes the Sellafield site, formally expressed an interest in being considered. Cumbria County Council also did so in December 2008 and Allerdale Borough Council, to the north of Copeland, followed in early 2009. They have jointly formed the West Cumbria MRWS Partnership, involving a wide range of local political and business groups, which is examining all aspects of the repository proposal and engaging in public discussion to judge the level of local support. The Partnership will make a recommendation to the three local authorities on whether to proceed to the next phase of the process and formally 'decide to participate'. This is likely to happen later in 2010 following an initial geological screening of west Cumbria by the British Geological Survey, applying a range of high-level exclusionary criteria laid down in the 2008 White Paper.

It is intended to return HLW, in glass form, to overseas client countries, a process which finally began in 2010 with return of material to Japan. The amounts involved are currently estimated at some 1,100m³ of liquor equivalent. Following a public consultation in January 2004, the government announced in December 2004 the approval of plans to allow BNFL to develop the practice of substitution, whereby L/ILW wastes would be substituted for HLW of corresponding activity and placed in a UK repository, if and when built, thereby reducing the volumes of wastes requiring repatriation. The ILW that will now remain at the Sellafield site in Cumbria will be stored awaiting the development of a deep repository by RWMD.

A vitrification plant (known as WVP) began operation at Sellafield in 1991. A third line was built in 1994 but only received final regulatory approval for commissioning in December 2001 following numerous delays. Current plans envisage cooling of UK-derived HLW at Sellafield for between 50-100 years before disposal.