Evaluation of a Coolant Injection into the In-Vessel with a RCS Depressurization by using SCDAP/RELAP5

摘要

As part of the evaluations for a severe accident management strategy, a coolant injection into the in-vessel with a reactor coolant system (RCS) depressurization has been evaluated by using the SCDAP/RELAP5 computer code. Two high pressure sequences of a small break loss of coolant accident (LOCA) without safety injection (SI) and a total loss of feed water (LOFW) accident have been analyzed in optimized power reactor (OPR)1000. The SCDAP/RELAP5 results have shown that only one train operation of a high pressure safety injection at 30,000 seconds with a RCS depressurization by using one condenser dump valve (CDV) at 6 minutes after an entrance of the severe accident management guidance (SAMG) prevents a reactor vessel failure for the small break LOCA without SI. In this case, only train operation of the low pressure safety injection (LPSI) without the high pressure safety injection (HPSI) does not prevent a reactor vessel failure. Only one train operation of the HPSI at 20,208 seconds with a RCS depressurization by using two SDS valves at 40 minutes after an initial opening of the safety relief valve (SRV) prevents a reactor vessel failure for the total LOFW.