Analysis of Long Term Core Cooling Capability of the APR1400 Considering LOCA Generated Debris

The fibrous materials may collect on the bottom nozzle of fuel assembly (FA) and would seriously impede flow into the core. Chemical products could be deposited on the surface of cladding. The debris effect causes a problem to remove decay heat from the core with the coolant. The concern described above is a real challenge to provide for long term core cooling (LTCC) capability. In this study, an analysis of LTCC capability for APR1400 considering the effect of LOCA generated debris has been performed using the RELAP5 code. In this paper, the long term core cooling capability of the APR1400 was evaluated with the effect of LOCA generated debris. The partial inlet blockage model and the chemical deposition model were adopted to simulate the effect of LOCA generated debris. The results indicate that the long term core cooling capability of the APR1400 can be maintained in the safe state after ECCS switchover to recirculation from the sump. The peak cladding temperature of the hot channel shows at much lower level than the critical temperature of the cladding