Real time value measurement with Feynman- method utilizing time series data acquisition on low enriched uranium system

Tonoike, Kotaro ; Yamamoto, Toshihiro; Watanabe, Shoichi; Miyoshi, Yoshinori

As a part of the development of a subcriticality monitoring system, a system which has a time series data acquisition function of detector signals and a real time evaluation function of alpha value with the Feynman- method was established, with which the kinetic parameter (alpha value) was measured at the STACY heterogeneous core. The Hashimoto's difference filter was implemented in the system, which enables the measurement at a critical condition. The measurement result of the new system agreed with the pulsed neutron method.