Governmental approval has been granted for the construction and operation of a dry storage facility for used nuclear fuel at Sizewell B, the UK's only pressurized water reactor (PWR).
Building work on the store will begin in the summer of 2012, and is expected to take about 18 months. The facility will begin accepting fuel from 2015, according to plant owner and operator EDF Energy. The store will be located within the boundaries of the existing station site.
Referring to a six-week public consultation, Sizewell B station director Jim Crawford expressed the company's pleasure at being able to start work on the new facility. "This is a mature technology that is widely used around the world to safely store spent fuel," he said.
Sizewell B, which started up in 1995, is the UK's newest nuclear power plant and its only PWR. Used fuel from the plant is currently stored on site in a fuel storage pond, which has sufficient capacity to last until 2015 by which time the dry storage facility should be operational.
When it is removed from a nuclear reactor, the highly radioactive and heat-producing used fuel is placed in a storage pond where it is cooled and its radioactivity rapidly decreases. It can ultimately be reprocessed to remove potentially reusable uranium-235 and plutonium, or disposed of as high-level radioactive waste. Dry storage is an interim measure available after the used fuel has spent several years in the pond, which involves placing it in welded metal canisters within concrete casks. It is in use at numerous nuclear facilities around the world – 55 sites are licenced to store used fuel in dry storage facilities in the USA alone.
The UK operates two reprocessing plants, both at the Sellafield site: a dedicated facility for reprocessing used fuel from the UK's earlier Magnox nuclear power plants, most of which are now shut down, and the Thermal Oxide Reprocessing Plant (Thorp), which was commissioned in 1994 and has treated used fuel from the UK's Advanced Gas-cooled Reactor (AGR) fleet and light water reactor fuels from overseas customers. However, there are no reprocessing contracts in place for used AGR fuel from 2007 onwards, nor for used fuel from Sizewell B.
A further 6600 tonnes of used AGR fuel is expected to arise by the end of the plants' operating lifetimes - all are due to close down by 2023 - and will need to be treated or stored. The Department of Energy and Climate Change has stipulated that the new dry store is to used exclusively for used fuel and associated fuel components originating from the Sizewell B PWR plant.
The fate of the plutonium already separated from UK used fuel, and of used fuel from the AGR program, is under review as discussions continue on the future of Thorp, which will require refurbishment or replacement to tackle the AGR fuel inventory, and on the potential recycling of plutonium in mixed oxide fuel.