Study on nuclear energy system considering environmental load reduction of waste disposal in diversification of nuclear fuel cycle conditions, 3; Simplification of MA separation process based on reasonable MA recovery rate by environmental impact assessment of radioactive waste disposal

Matsumura, Tatsuro  ; Asano, Hidekazu*; Sakuragi, Tomofumi*; Hamada, Ryo*; Han, C. Y.*; Nakase, Masahiko*; Chiba, Go*; Sagara, Hiroshi*; Takeshita, Kenji*

The issue of high-level waste disposal is important for the sustainable use of nuclear energy. P&T technology of long-lived and highly radiotoxic MA is a key technology. The MA separation process, which separates MA from the high-level waste, is one of the essential technology for realizing the P&T technology. JAEA has been developing the SELECT process using the solvent extraction technique for the MA separation process. Target values for separation performance were 99% recovery rate based on radiotoxicity evaluation and 95% MA product purity from evaluation of the performance of transmutation system. The separation process was demonstrated by the test using genuine HLW. SELECT process consists of two steps. The second step for MA/RE separation requires 40 extraction stages for the target value, and there was a issue of introduction and operation costs. Therefore, we set a reasonable recovery rate based on the evaluation of the environmental impact of the disposal site. Based on the target value, quantitative evaluation was carried out using the PARC-MA code, and the number of extraction stages in the MA/RE separation process and the purity of the MA product were obtained. We believe that the configuration of a realistic simplified MA separation process has been clarified.