ナトリウム冷却高速炉の炉心損傷事故時の制御棒材の共晶溶融挙動に関する研究,17; 溶融ステンレス鋼/BC固液反応後の元素濃度分布

Study on eutectic melting behavior of control rod materials in core disruptive accidents of sodium-cooled fast reactors, 17; Reaction behavior between molten stainless steel and solid boron carbide

中村 勤也*; 太田 宏一*; 江村 優軌; 高井 俊秀  ; 山野 秀将   

Nakamura, Kinya*; Ota, Hirokazu*; Emura, Yuki; Takai, Toshihide; Yamano, Hidemasa

ナトリウム冷却高速炉の炉心損傷時に、燃料に先行して制御棒が溶融・移行する挙動解析モデルを構築するため、溶融ステンレス鋼(SS)と中性子吸収材(BC)の高温反応後のSSを対象に、構成元素の濃度分布を測定した結果、ホウ素濃度は水平方向に一様である一方、鉛直方向には下方ほど低下する傾向が認められた。

The purpose of this study is to develop the behavior analysis model of control rods that seem to melt and relocate prior to fuel melting during a core disruptive accident in a sodium-cooled fast reactor. The authors measured the concentration distribution of molten stainless steel (SS) and also the SS that reacted with the neutron-absorbing material, BC, at a high temperature. It showed that the boron concentration was uniform in a horizontal direction. In a vertical direction, however, it became lower toward the bottom.