Application of the modified neutron source multiplication method to the prototype FBR Monju

修正中性子増倍法の高速原型炉「もんじゅ」への適用

Truchet, G.*; Van Rooijen, W. F. G.*; 島津 洋一郎*; 山口 勝久

Truchet, G.*; Van Rooijen, W. F. G.*; Shimazu, Yoichiro*; Yamaguchi, Katsuhisa

修正中性子増倍法(MNSM)を高速原型炉「もんじゅ」に適用した。「もんじゅ」の特異性のうちMNSM因子に大きな影響を及ぼす要素は、炉心近傍にカリフォルニウム中性子源があることと、中性子検出器が炉容器外の離れた位置にあること。検出器の計数率の評価では、炉容器から外部の検出器までの伝播計算を実施した。二つの未臨界状態に対して反応度を評価し、2010年の再起動試験データと比較した。MNSM法による反応度計算結果は、他の方法から得られた反応度とよい一致を見た。

The Modified Neutron Source Method (MNSM) is applied to the prototype FBR Monju. Among Monju's particularities that have a big influence on the MNSM factors are: the presence of two californium sources near the core and the position of the detector, which is located far from the core outside of the reactor vessel. In order to evaluate the detector count rate, a propagation calculation has been conducted from the reactor vessel to the external detector. For two subcritical states, an estimation of the reactivity has been made and compared to experimental data obtained in the restart experiments at Monju (2010). Results indicate a good agreement between the MNSM reactivity and the reactivity measured with other methods.