Injection Transition Analysis of PLGS MPLP ECC System

Abstract

To analyze the transition from MP ECC to LP ECC injection, a RELAP5 model has been developed for the Point Lepreau Generating Station (PLGS) MP/LP ECC system. By using this model, some transition analyses have been performed with emphasis on stroke times of the dousing tank suction test isolating valves and the recovery sump isolating valves. The results indicate that if either in-line valve pair of the dousing tank isolation valves fails to close, air could be ingested by the ECC pumps shortly after the dousing tank is empty.