System performance test of mechanical decladding system for FBR fuel reprocessing

Japan Nuclear Cycle Development Institute (JNC) has been developing a new mechanical decladding system for FBR oxide fuel. The mechanical decladding system consists of the fuel pin crushing step (mechanical crusher), the hull separation step (magnetic separator) and the hull rinsing step (melting separator). The system mock-up test device is fabricated, and the performance tests are carried out with simulated oxide fuel pins. As the results, the following performance of each device was confirmed. The lifetime of the crushing blades of mechanical crusher were more than 1 year, and practical use. The vibration classifier could be separated 3 groups (wrapping wire, small particles and large particles), and recovered the majority of the wrapping wire. High fuel purity and a high fuel separation efficiency were obtained by the multi-stage magnetic separator. The fuel and the hull could be roughly separated, and the majority of the fuel could be recovered easily by the Cold Crucible Levitation Melting (CCLM) technology. As the above results, each device performance was satisfied the specification of commercialized scale reprocessing plant, and the high fuel recovery performance achieved by the combination of the multi-stage magnetic separation and the hull melting separation. Therefore, we can establish innovative engineering design of the mechanical decladding system. In the future, hot demonstration data using spent fuel will be carried out, and remote maintenance design will be conducted. (author)