Integral effect test on cooling performance of hybrid safety injection tank

This paper reports an experimental research on the performance of the passive emergency core cooling system (PECCS) using an integral effect test facility in Korea Atomic Energy Research Institute (KAERI). The PECCS consists of two hybrid safety injection tanks (H-SIT), two medium pressure safety injection tanks (MP-SITs) and an automatic depressurization system consisting of four stages. In this study, an integral effect test (IET) was conducted on a loss of coolant accident (LOCA), which requires the operation of the primary makeup system. The H-SIT (SITs #1 and #3) injection starts successfully when the primary side pressure falls to 10.0 MPa, and the MP-SIT (SITs #2 and #4) injection starts when the pressure falls further to 4.21 MPa. The coolant injection of H-SIT occurs intermittently at certain points of time, rather than continuously. It can be seen that the flow generation of the H-SIT near the pressure plateau occurs exactly when the secondary side is depressurized.