Pressure and Temperature Transient Analysis of 500 MWe PHWR Containment by Computer Code PACSR

Abstract

The containment of 500 MWe PHWR essentially incorporates a vapour suppression pool for limiting the pressure rise during a Loss of Coolant Accident (LOCA) or Steam Line Break (SLB), a double envelope for minimizing the radioactivity release to the environment, air coolers and control gas discharge for depressurization of the primary containment. The analysis for LOCA and SLB induced pressure temperature transient for the pressure suppression containment is done by the computer code PACSR (Post-Accident Containment System Response). The code models the containment-as two volumes representing the drywell and wetwell, with connection via the vent shafts and suppression pool. Also modelled are various features for containment depressurization and cool down, viz. containment air coolers and structural walls/floors (which serve as heat sinks) and the controlled gas discharge system. In this paper some of the specific modelling details the code are discussed and the results of the pressure temperature transient analyses carried out for the 500 MWe containment are presented.