MELCOR 1.8.5 Sensitivity Study of Molten Core Concrete Interaction Experiment, SWICCS-1, 2 and 3

In a postulated core melt accident, if the molten core is not retained in-vessel despite taking severe accident mitigation actions, the core debris will relocate in the reactor cavity region. There, it will interact with structural concrete and could potentially result in basemat failure (through erosion or overpressurization) and consequent fission product release to the environment. Although a methodology of cooling the molten core by adding water on its top is selected as a severe accident management strategy in case molten core is released outside a reactor vessel, the possibility of a long-term cooling is still unresolved. In the OECD/MCCI project scheduled for 4 years from 2002. 1 to 2005. 12, a series of tests are being performed to secure the data for cooling the molten core spread out at the reactor cavity and for the long-term CCI (Core Concrete Interaction). In this study, SWICCS-1, 2 and 3, of the SWICCS tests of OECD/MCCI project, was assessed using MELCOR1.8.5 and the sensitivity parameters' selection of CAV package were investigated in SWICCS-1 and the same options were applied to another experiments SWICCS-2 and -3