Uncertainty Analysis of the Molten Corium-Concrete Interaction during Severe Accidents in Typical PWR

This paper illustrates an application of a severe accident analysis code, MAAP, to the uncertainty analysis of molten corium-concrete interaction (MCCI) phenomena in case of severe reactor accidents. The MAAP code is a system level computer code capable of performing integral analyses of potential severe accident progressions in nuclear power plants, whose main purpose is to support Level 2 probabilistic safety assessment or severe accident management strategy developments. The code employs lots of user-options for supporting sensitivity and uncertainty analysis. The present application is mainly focused on determining an estimate of the axial/radial concrete erosion and corium coolability in the reactor cavity during MCCI. Key modeling parameters and phenomenological models employed for the present uncertainty analysis are closely related to heat transfer coefficients, concrete property, and corium debris configuration. The Korean standardized nuclear power plant, OPR-1000, has been used as a reference plant for the analysis