Continuous-operation test at engineering scale uranium crystallizer system

Washiya, Tadahiro ; Tayama, Toshimitsu; Nakamura, Kazuhito; Yano, Kimihiko ; Shibata, Atsuhiro ; Nomura, Kazunori ; Chikazawa, Takahiro*; Nagata, Masanobu*; Kikuchi, Toshiaki*

Japan Atomic Energy Agency (JAEA) and Mitsubishi Materials Corporation(MMC) are developing the crystallization process for FBR fuel reprocessing. The uranium (U) crystallization process is a key technology for NEXT(New Extraction System for TRU Recovery) process that was evaluated as the most promising process for future FBR reprocessing. We fabricated an engineering-scale crystallizer and continuous operation test was carried out to investigate steady and non-steady state conditions. Crystal accumulation and blockage phenomena were confirmed in this test. And monitoring method and resume procedure were considered. As the test results, no significant event was observed in the steady state test. And in the non-steady state test, process fluctuation was detected by the monitor of the screw torque and liquid level in the crystallizer, and all failure events can be recovered by appropriate resumed procedures.