In a long term management of the nuclear fuel, Pu contained in the spent fuel would be extracted by reprocessing in order to be recycled in PWR or to be stored to feed future GEN IV reactors. U is better recycled in PWR, as long as it is attractive. This paper proposes and compares solutions that allow multiple recycling of U in PWR.
All the solutions are based on blending: either (a) the Enriched Reprocessed U (ERU) assemblies can be reprocessed together with Enriched Natural U (ENU) assemblies and the resulting Reprocessed U (RepU) be re-enriched to produce the next generation ERU, or (b) RepU can be blended with natural U before enrichment of the mixture, or with ENU after its own enrichment. These solutions are compared with each other in terms of achievable equivalence, technical feasibilities and economic efficiency.