Measurement and analysis for determination of power coefficient of reactivity of an operating CANDU6

Abstract

The power coefficient of reactivity (PCR) needs to be negative to achieve the inherent safety of a reactor, but the PCR of CANDU-6 has been evaluated to be positive in recent studies. In this circumstances, an experiment was performed at a CANDU-6 reactor in Korea to measure the PCR of CANDU-6. Based on the measurement data, the PCR was evaluated by a newly proposed methodology which requires several estimations of reactivity variation due to liquid zone controllers, xenon, etc. Consequently, the PCR of CANDU-6 was evaluated to be about 0.5 pcm/%Power which is slightly smaller than the latest official value, 1.7 pcm/%Power.