Smooth Transition from Light Water Reactors to Fast Breeder Reactors by Flexible Fuel Cycle initiative (FFCI)

In order to reasonably manage the transition period from existing light water reactors (LWR) to future fast breeder reactors (FBR), the authors propose an innovative fuel cycle system called Flexible Fuel Cycle Initiative (FFCI) which consists of LWR and FBR spent fuels reprocessing. LWR fuel reprocessing provides about 90% uranium removal from LWR spent fuel, then the composition of remaining spent fuel (recycle material) is about 50% uranium, 15% plutonium and 35% other nuclides. Recycle material is transferred to FBR fuel reprocessing to recover plutonium and uranium followed by mixed oxide (MOX) fuel fabrication for FBR. Depending on the introduction time of FBR, recycle material (about 1/10 volume of original spent fuel) may be stored until the construction of FBR. The FFCI has some advantages compared to full reprocessing facilities for LWR and FBR spent fuels to produce FBR fresh fuels. The LWR reprocessing facility becomes much smaller due to no Pu-U recovery and fabrication. The recycle materials can be reprocessed in the FBR reprocessing facility by using its surplus capacity without disturbing the FBR spent fuel reprocessing. The recycle materials can supply higher content of plutonium to FBR and can be compactly stored in case of FBR introduction delay. more » The plutonium balance was calculated under several conditions, which revealed that the FFCI system could meet the plutonium demand while creating no excess plutonium. (authors) « less