ファイマン-α中性子相関解析による近畿大学原子炉の熱出力校正

摘要

This paper presents an applicability of the extended Feynman-a correlation method to reactor power measurement. In the extended method, higher-order difference filters are implemented and dead-time effect of neutron counter is considered. A series of the correlation measurements were performed in the UTR-KINKI reactor to demonstrate the applicability of the extended method. At a critical state, the reactor power inferred from saturated correlation amplitude is consistent with indication of linear power monitor of the reactor. At subcritical states, not only the correlation amplitudes but also the subcriticality of these states require for the determination of reactor power. In prompt decay constants and subcriticalities obtained from the constants, detector-position dependence, i.e., spatial effect has significantly observed. These subcriticalities have also led to the significant spatial dependence of the reactor power inferred. When reference subcriticalities determined from source jerk experiment have employed instead of the above spatially dependent subcriticalities, the inferred reactor power has slight spatial dependence and agrees with indication of linear power monitor.%研究炉ゃ臨界集合体の原子炉出力計の校正には、中性子束積分法が用いられる場合が多い。この校正法では、中性子束と巨視的核分裂断面積の積が炉心燃料領域にわたって積分される。中性子束分布は、金属箔放射化法や超小型核分裂計数管等を採用して測定される。このような校正は長時間の原子炉運転や高価な機器を必要とする。さらに、測定された中性子束は自己遮蔽効果等を補正しなければならない。