Thermal-Hydraulic Analysis of Loss of Shutdown Cooling System Event During Midloop Operation in Pressurized water Reactors

摘要

The thermal-hydraulic behavior in pressurized water reactors during midloop operation following the loss of the shutdown cooling system (SCS) is analyzed using the RELAP5/MOD3.1 code. The steam generator (SG) can be used as an effective means of decay heat removal by means of reflux condensation which occurs in the SG U-tubes. To identify that the reflux condensation in the SG is capable of removing core decay heat in the event of loss of SCS during midloop operation, the transient is simulated for 10000 seconds. Of particular concerns are reactor coolant system (RCS) pressure and temperature behavior with time. Core boiling time, RCS water level, void fraction distribution in the RCS, and fuel rod temperature are also predicted.