Study on high conversion type core of Innovative Water Reactor for Flexible Fuel Cycle (FLWR) for Minor Actinide (MA) recycling

Fukaya, Yuji   ; Nakano, Yoshihiro ; Okubo, Tsutomu

Conceptual design studies on the Innovative Water Reactor for Flexible Fuel Cycle (FLWR) have been performed at Japan Atomic Energy Agency (JAEA), and study on high conversion type core of FLWR (HC-FLWR) for MA recycling was started. Because HC-FLWR is the near-term technology with a conversion ratio around 0.85, it would be useful if HC-FLWR can recycle MA. The design criteria and requirements for the core are set as follows: The void reactivity coefficient should be negative value. And the discharge burn-up should be around 50 GWd/t. The parametrical survey with core burn-up calculations was performed. From these survey calculations, some feasible design ranges have been obtained for MA recycling core. The Puf enrichment of MOX fuel is 13 wt%. The core height is 116 cm. The fuel rod diameter is 9 mm. The core average void fraction is about 50%. In these reactor core specifications, around 2 wt% of Np or Am can be recycled in the HC-FLWR MOX fuel.