Analysis of SBWR passive containment cooling following a LOCA

A condensation heat transfer mechanism of long-term decay heat removal, the Passive Containment Cooling System (PCCS), has been incorporated into the design of the Simplified Boiling Water Reactor (SBWR). A second independent system, the Isolation Condenser condensation heat exchange system (ICS), may be used in conjunction with the PCCS to increase the rate of heat removal from the SBWR. TRACG (Transient Reactor Analysis Code) is used to evaluate the system behavior for long-term decay heat removal following a LOCA. The present analysis focuses on SBWR containment cooling with two possible combinations of the IC and PCC systems. Results of TRACG calculations show that: (1) the PCCS alone is adequate for decay heat removal: (2) containment cooling is mildly enhanced by operation of the ICS in conjunction with the PCCS. (author)