RFSP Simulation of a Reactor-History Slice Featuring Saturated Zone-Control Compartments

Abstract

On 1988 September 15 there was a spatial-control-impairment incident at Point Lepreau. Water fills in two of the 14 zone-control compartments began to saturate high, thereby depriving the corresponding zones of normal spatial control. A high bundle power ensued in zone 5. The on-line flux-mapping program originated an alarm on bundle power >900 kW. The operator responded to the alarm by adding boron to the moderator, which brought the zone fills back to their working range, thus restoring spatial control. This incident was analyzed with the fuel-management code RFSP. A version of the program with bulk- and spatial-control functions and the ability to model xenon transients in 3 dimensions was used. The simulations illustrate the capabilities of the code and quantify the sensitivity of the results to the inherent uncertainties in zone-compartment water fills. The RFSP maximum bundle power through the period was 892 kW.