'ORIENT-Cycle' - Evolutional Recycle Concept with Fast Reactor for Minimising High Level Waste

JNC has proposed an evolutional concept of fast reactor recycle system for minimizing high-level waste (HLW) by adopting an unconventional recycling scheme based on the idea of 'rough removal of unnecessary elements' instead of a conventional one as 'pure recovery of necessary elements'. The concept was named 'ORIENT-cycle' (Optimization by Removing Impedimental Elements). 'Unnecessary elements' to be removed were listed up from various aspects such as core design, front end and back end of the fuel cycle. Stable fission products that amount to about 60 wt% of all FPs were identified as one category of key 'unnecessary elements' from a neutronic aspect and also final disposal aspect because they were major parasitic neutron absorbers if recycled and were not required to be disposed in deep geological media. Adaptable separation schemes and the neutronic feasibility of the multi-recycling were discussed. The production rate of HLW was reduced by a factor of around 10 compared with a conventional cycle. (authors)