Parametric studies on nuclear criticality safety design of MOX fuel fabrication facility

Shimizu, Yoshio ; Suitsu, Yuichi; Murakami, Tatsutoshi ; Yuri, Akiya

Nuclear criticality safety evaluations for the fast breeder reactor's MOX fuel fabrication facility were performed. In the parametric studies made with SCALE, following three cases are here introduced. (1) The effect of the plutonium isotopic ratio on Pu (U, Pu, Pu) mass control were evaluated. The design conditions of the plutonium isotopic ratio under the operating condition were adjusted from the evaluation. (2) The moderation effects of organic materials in MOX fuel fabrication facility were evaluated. The water contents equivalent moderation effects to organic contents were obtained from the evaluation. (3) The effects of nonuniform mixture of MOX powder and water were evaluated by two-phase model and SMORES. The k, which differ from the k of uniform model, were evaluated.