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

MOX燃料製造施設の臨界安全に関するパラメトリックな検討

清水 義雄 ; 水津 祐一; 村上 龍敏 ; 由利 明哉

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

高速増殖炉のためのMOX燃料製造施設に対する臨界安全評価を実施した。次の3つのケースに対してSCALEを用いたパラメトリックな検討を行った。(1)Pu(U, Pu, Pu)質量管理におけるプルトニウム同位体組成の影響を評価し、運転時の管理条件下における核的制限値の設定条件を設定した。(2)MOX燃料製造施設で用いられる有機物に対する減速効果として、有機物含有率と等価な水分含有率を評価した。(3)MOXと水の不均一効果として、2層モデル及びSMORESを用いて、均一モデルとの差を評価した。

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.