Development of sweepout model for the APR1400 downcomer

According to the experiments of Upper Plenum Test Facility (UPTF) and the those related to the multi-dimensional phenomena in the Advanced Power Reactor 1400MWe (APR1400) downcomer, the sweepout has been identified to play an important role in depleting the coolant inventory in the reflood and the long term cooling phase of Large-Break Loss-of-Coolant Accident (LBLOCA). Thus, the sweepout separate effect test was performed to investigate the mechanism and to estimate the amount of the coolant discharged by sweepout. Deriving the non-dimensional parameters by analytic study, the results of experiment were correlated to devise the sweepout model, which calculates the critical void height and the flow quality at the break. The developed model was validated with the results of counter-part experiments performed in KAERI and SNU