Comparison of commissioning test results with physics simulations in a CANDU reactor.

Abstract

This paper presents the comparison of simulated and experimental results of various experiments performed during the Phase B Comrnissioning of Pickering NGS B Units 5, 6, 7, and 8 and Bruce NGS B Units 5, 6 and 7. During Phase B Commissioning, a reactor is brought. to criticality for the first time. Once the criticality is achieved, a number of experiments are performed to confirm the nuclear characteristics of the reactor at low power but before the reactor had operated at significant power. These experiments performed fall into two distinct categories: (a) static tests. and (b) dynamic tests. The static tests comprise the determination of critical poison concentration at the time of first criticality, calibration of zone controllers. and measuring the reactivity of various reactivity devices. The dynamic tests comprise power rundowns with both the shutdown systems activated one at a time. The physics simulations were performed before the commissioning of the reactor using the reactor physics computer codes available at Ontario Hydro. The results have shown that our reactor physics codes are able to simulate overall neutron balance and modelling of the reactivity devices.