Transactions of the Korean Nuclear Society Virtual Autumn Meeting December 17-18 Experimental Study on the Counterpart Test of LSTF 1% SBLOCA at Reactor Pressure Vessel Top with Accident Management Action

After the Fukushima accident, interest on the safety assessment of the existing nuclear power plant increased. And such interest is expanded to further demand for experiments which can give information related to the transient state of nuclear power plant. Thus, importance of the integral effect test (IET) result performed at the ATLAS facility, which is the third largest IET facility in the world, is increasing, not only within Korea but also in the nuclear R&D programs such as the OECD/NEA international joint project. In order to resolve key thermal-hydraulic safety issues related to multiple high risk failures highlighted from the Fukushima accident, various accident scenarios were considered as test items of the second phase of OECD/NEA ATLAS international joint project (hereafter, OECD-ATLAS2 project). As one of the test items performed under the OECDATLAS2 project, the B5.1 test was defined as a counterpart test with respect to the LSTF SB-PV-07 test. The target scenario for the SB-PV-07 test was a 1% small-break loss-of-coolant accident (SBLOCA) at reactor pressure vessel (RPV) top in a pressurized water reactor (PWR) under assumption of total failure of high pressure injection (HPI) system. In this test, an accumulator (ACC) tank injection was assumed to be available and the two kinds of accident management (AM) actions, manual injection of HPI as the first AM action and the 2 system depressurization as the second AM action, were utilized [1]. The objective of this test is to investigate the general thermal hydraulic phenomena during an SBLOCA with accident management actions. As a counterpart test of the LSTF SB-PV-07 test, the test result was analyzed to identify scaling characteristics of ATLAS test facility compared with other IETs.