燃料デブリの臨界特性を明らかにする定常臨界実験装置STACY更新炉の整備,7; 炉心周辺機器の反応度効果の事前評価

Modification of STACY for study of criticality characteristics of fuel debris, 7; Evaluations of reactivity effects of equipment in a core tank

郡司 智  ; 荒木 祥平   ; 須山 賢也; 井澤 一彦 

Gunji, Satoshi; Araki, Shohei; Suyama, Kenya; Izawa, Kazuhiko

STACY更新炉の臨界実験開始にあたり、臨界水位を正しく解析するためには有意な反応度効果を有し臨界水位に影響を与える炉心周辺機器を同定して計算モデルで考慮する必要がある。炉心タンク内主要機器及び可動装荷物駆動装置の有する反応度 について計算解析で評価し、実験計画に必要な知見を得た。

For the start of critical experiments in the modified STACY, it is necessary to identify core tank components that have significant reactivity effects in order to evaluate its critical water height. Therefore, reactivity effects of a few main in-core tank components which are expected having neutron absorption effects were evaluated by Monte Carlo computation. As the results, it was found that a few components have significant reactivities. Computation models for experimental designs need to take these components into account.