Magnox Reprocessing Plant
A nuclear fuel reprocessing plant is a chemical plant, which separates plutonium and unused uranium from spent nuclear fuel. Because its raw material is intensely radioactive, all operations must be carried out by remote control, behind heavy shielding in place due to the skills of Sellafield engineers.
Firstly the cladding around the spent fuel element is stripped off then the fuel rod is dropped into a vat of nitric acid which dissolves it ready for reprocessing. This nitric acid solution is then treated with various solvents to separate out plutonium and unused uranium, leaving behind radioactive liquid waste. The uranium metal fuel used in Magnox reactors and the uranium oxide fuel used in most other reactor types have to be treated slightly differently, which is why there are two different reprocessing plants at Sellafield.
The Sellafield Magnox Reprocessing Plant (B205)
This plant came on stream in 1964 to reprocess spent nuclear fuel from the original generation of Magnox reactors. The first of these was Calder Hall, which was the world’s first nuclear power station to generate electrical power on an industrial scale, and subsequently creating nuclear engineering jobs in Cumbria.
Other similar reactors followed; not only in this country, but also in Japan, Italy and North Korea. Engineering skills were therefore exported, and as a backfill, engineering vacancies in Cumbria were created.
Calder Hall was shut down in 2003 after having been in use for nearly 47 years. Although many other Magnox reactors have also been shut down there are still a few still in operation, and it is expected that the Magnox reprocessing plant at Sellafield will remain operational until the last of these reactors is taken out of service and the fuel finally reprocessed.
The plant uses the ‘plutonium uranium extraction “Purex”’ method for reprocessing spent fuel, with tributyl phosphate as extraction agent. As with other reprocessing systems, the Purex process produces uranium, plutonium and fission products as output streams. This is why highly skilled chemical engineers are in such high demand.
Over the 30 years from 1971 to 2001, the B205 Magnox reprocessing plant at Sellafield has reprocessed over 35,000 tonnes of Magnox fuel, with 15,000 tonnes of fuel being regenerated. It is considered essential to continue reprocessing magnox fuel since it corrodes if stored underwater, and there are currently no other proven and acceptable dry storage systems available. One of the economic benefits of this being that even if Sellafield closed tomorrow, engineering jobs in Cumbria would be secure for many generations. This has a positive impact on engineering vacancies at Sellafield, as they will continue to be in demand and provide an economic benefit to west Cumbria for a long time.