Conceptual Design Study on Advanced Aqueous Reprocessing System for Fast Reactor Fuel Cycle

摘要

The design study of an aqueous reprocessing system has been progressed for the feasibility study on commercialized fast reactor cycle systems in Japan. A simplified PUREX process, with the addition of a uranium crystallization step and a minor actinide (MA) recovery process was proposed as the NEXT process. For the simplified PUREX process and the SETFICS/TRUEX process for MA recovery, small-scale hot tests were conducted. The test results showed the decontamination factor (DF) of 10{sup}5 for the U, Pu and Np product was a reasonable target for the simplified PUREX process. Concerning to the Am and Cm product, the DF of rare earth elements (REs) and the other fission products (FPs) were over 10 and over 10{sup}2, respectively. For economical competitiveness, an aqueous reprocessing plant with the capacity of 200 tHM/yr cleared the target cost, while the plant with the capacity of 50 tHM/yr did not clear it. For efficient utilization of resources, the calculated U and TRU recovery of both plants was over 99 wt%. Using salt-free reagents and repeating concentration of waste solutions, the environmental impact was reduced. Pu was not isolated through the whole processes in the NEXT process in order to keep the proliferation resistance.