Application Results MAAP 5.0.2 to Domestic APR1400 Nuclear Power Plant

There are so many changes in the models such as the Lower head plenum model, Debris Coolability model, Molten Core Concrete Interaction, and the analysis scope is enlarged to the phenomena in the spent fuel pool and the half-loop operation. As a kind of post-Fukushima measures, KHNP is developing the probabilistic safety assessment (PSA) and severe accident management guideline (SAMG) for low power and shutdown (LPSD) mode and MAAP 5.0.2 should be used in these projects as a major analysis program. So, first of all, it is necessary that the parameter file for domestic NPP should be upgraded as current Ver. MAAP4 to Ver. MAAP 5.0.2. KHNP developed the draft version of parameter file for APR1400 type NPP and is being tested for some basic severe accident sequence. In this study, we try to share the information for newly developed parameter and compare the analysis results using MAAP 5.0.2 with previous results using MAAP4. Currently, while developing the LPSD PSA and LPSD SAMG as a kind of post-Fukushima measures, KHNP have the plan in order to upgrade the old parameter file based on MAAP4 to that based on MAAP5.0.2 for all domestic nuclear power plants. As the first effort, we developed the MAAP 5.0.2 parameter file for APR1400 type NPP. In this study, we can find that the newly developed MAAP5.0.2 parameter file for domestic APR1400 type is appropriate for actual analysis. But, as a draft version, it is judged that it should be revised through the sensitivity studies, especially focused on the newly introduced models in MAAP 5.0.2