Innovative powder production and granulation for advanced MOX fuel fabrication

Kurita, Tsutomu ; Kato, Yoshiyuki ; Yoshimoto, Katsunobu; Suzuki, Masahiro ; Kihara, Yoshiyuki; Fujii, Kanichi

With regard to advanced MOX fuel fabrication, a new concept in which one vessel especially designed to meet microwave de-nitration is utilized also for crushing and for granulation, without organic lubricant nor powder transfer across the processes, was introduced for innovative MOX powder production. In order to realize this concept, two attempts were made: A specially designed three blade impeller coupled with auxiliary blade. A uniquely shaped mixing blade coupled with an auxiliary blade having auto-orbital hybrid rotation. The mixing blade promotes the growth of particles, whereas the auxiliary blade suppresses the overgrowth by chopping larger particles. These granulators use a little water as binder. As a result, major diameter of granule 400-1000 micron and flow-ability 82-85 was obtained with fine WO model powder. Therefore, a prospect to satisfy both desirable powder properties and simplified nuclear material production was opened, as well as improvement of working efficiency and cut down on costs.