Review of developments in U.K. commercial reprocessing

Abstract

The U.K. fuel cycle (Fig. 1) is based on reprocessing of the nuclear fuel, which is retained in most modern reactors for approximately one year. The spent fuel has a high residual energy content from initially enriched uranium, in addition to the predominant proportion of the activity generated by the nuclear industry. Spent fuel has been reprocessed at Seilafield in Cumbria since 1952 and the present reprocessing plant was brought on-stream by the United Kingdom Atomic Energy Authority in 1964 to meet the first Civil (5 GW) Magnox Reactor Power Programme. British Nuclear Fuels was formed some seven years afterwards from the Authority to take over the Production Group and to carry out the established industrial operations including reprocessing. The commercial reprocessing operation, enabling the recovery of valuable uranium and plutonium resources for recycle and the isolation of fission products in conditioned form for eventual disposal, has therefore been a key part of the business of BNFL since the formation of the Company. Throwaway alternatives have been examined and rejected, although some matters of safeguards may be avoided and waste management is reduced to the encapsulation and safe disposal of the spent fuel elements. However, the total quantity of plutonium has to be accommodated in disposal with criticality complications also much greater long-term radiological hazard would result. Reprocessing is almost essential when fuel cladding is prone to corrosion outside the reactor system and, for instance, Magnox/uranium metal fuel, which is the basis of the first U.K. Civil Programme for power generation, generally requires reprocessing within two years of discharge. Advanced Gas Cooled Reactor fuel from the second programme, although clad in stainless-steel, should be reprocessed preferably within ten years. However, a longer period is possible if the