SUMP WATER USABILITY ANALYSIS FOLLOWING LB LOCA OF CANDU 6 REACTOR

摘要

This paper focused on the analysis of sump water usability as a source for low pressure emergency core cooling injection in CANDU 6 for large break loss of coolant accident, using GOTHIC-IST code. For a long term cooling, the operation of low pressure recirculation using an emergency core cooling pump is required. To operate an emergency core cooling pump, the net positive suction head of the pump should be satisfied. The maximum permissible temperature of sump water to meet the net positive suction head of an emergency core cooling pump is 87.73°C. In this study, the temperature and the level of sump water were monitored for the large break loss of coolant accident with malfunction of spray system and local air coolers. For all considered accident cases, the temperature of containment basement water was analyzed to be lower than 87.73°C and it was possible to operate the low pressure recirculation using an emergency core cooling pump for the most restricted scenario.