Development of mixing anlaysis model in reactor pressure vessel for pressurized thermal shock evaluation of korea NPP

摘要

Pressurized thermal shock (PTS) events are potentially theatening to the integrity of the irradiated reactor pressure vessel because the high thermal stress can result in a through-the-wall crack propagation.The purpose of the thermal mixing analysis in the plant specific PTS evaluation is to analyze the downcomer cooling behavior when the thermal stratification phencomer cooling behavior when the thermal stratification phenomenon is generated in the cold leg. The existing PTS mixing codes may be inadequate or over-estimate the effects of the PTS phenomena due to conservative boundary condition assumptions, dimensional nature of the calculation, or nodal limitations. Therefore, a 3 dimensional unsteady state numerical specific PTS evaluation of a Korea nuclear power plant (NPP). This paper presents the configuration and verification of KOMIX and the analysis results for steam generator tube rupture (SGTR) accident case.