An integral effects test of loss of residual heat removal during mid-loop operation

Loss of residual heat removal (RHR) during a mid-loop operation after plant shutdown has occurred in several nuclear power plants. Integral effect test facility was established to simulate the thermal hydraulics of Korean Nuclear Standard Power Plant under abnormal conditions during shutdown operations and several experiments were conducted at the facility. The major results from these experiments are presented in this paper, which addresses the rates of primary mass inventory reduction and core heat-up time in case of manways opened at various locations in the primary coolant system and the effects of nozzle dams failure and steam generator to remove decay heat in reflux condenser mode on core heat-up time