Real Time a Value Measurement with Feynman-α Method Utilizing Time Series Data Acquisition on Low Enriched Uranium System

Abstract

As a part of the development of a subcriticality monitoring system, a system which has a time series data acquisition function for detector signals and a real time evaluation function of the α value with the Feynman-α method was established, with which the kinetic parameter (α value) was measured at the STACY heterogeneous core. Hashimoto's difference filter was implemented in the system, enabling the measurement in a critical condition. The measurement result of the new system agreed with the pulsed neutron method. The α value was also evaluated by the newly developed algorithm of α-mode calculations for the Monte Carlo method, which was compared with the experimental value. Those computational and experimental α values show agreement within their uncertainties.