The visit, held on Thursday 26 February, was arranged to inform a study on interim storage being undertaken by CoRWM Sub-Group 6 (Waste, Spent Fuel and Nuclear Materials Inventory Management). Sub-Group 6 members Pete Bryant, Derek Lacey, Barry Lennox, and Simon Webb were joined by CoRWM member Mark Kirkbride. The study will report on current and future interim storage requirements for spent nuclear fuel and intermediate level waste (ILW), considering the UK nuclear legacy, the existing operational fleet and new build.
At Sizewell A, now in the early stages of decommissioning following de-fuelling between 2006 and 2014, members reviewed progress in the retrieval and conditioning of ILW, including material from the ponds. They discussed arrangements for transferring ILW, including by rail, to the Bradwell Interim Store, which is designed to accommodate waste from Bradwell, Sizewell A and Dungeness until reactor dismantling begins. Members noted the achievement of diverting approximately 92% of pond low level waste from the Low-Level Waste Repository (LLWR) to permitted landfill sites. This helps preserve capacity at the LLWR.
At Sizewell B, the group reviewed the management of spent nuclear fuel using the Holtec Dry Storage System. The on-site dry store is sized to accommodate all spent fuel arising from current operations, including any life extension, and has a design life of 100 years. Discussions covered inspection arrangements for dry fuel containers and the balance between assurance of fuel integrity and the potential risks associated with opening canisters for periodic inspection. It was noted that ILW is managed and stored on site, with some waste streams already in a form suitable for disposal in a future Geological Disposal Facility.
Across both sites, members observed clear strategies and well-developed plans for interim storage of ILW and, where applicable, spent nuclear fuel. The importance of embedding future transport arrangements to a Geological Disposal Facility within site decommissioning plans was highlighted, alongside the need to manage local resource pressures, including those associated with the construction of Sizewell C.
CoRWM would like to thank the teams at Sizewell A and Sizewell B for hosting the visit and for open and constructive discussions, which will support the committee’s independent advice to government on the long-term management of radioactive waste.