The Establishment and Application of TRACE/CFD Model for Maanshan PWR Nuclear Power Plant

In this study, a three-dimensional model was developed by using CFD and TRACE to simulate the flow behaviors and thermal-hydraulic phenomena in the downcomer and lower-plenum of Maanshan PWR nuclear power plant (NPP) reactor pressure vessel (RPV). Detailed geometries of vessel components such as neutron shield panels, core support, lower core plate, butt-type columns were considered in this model for flow calculations. Important settings of the present CFD model were first validated with the data of ROCOM facility. Following those settings and considering the geometries and operating conditions of Maanshan NPP, the CFD model was built. In order to provide sufficient transient boundary conditions for CFD simulations, TRACE model was coupled with the CFD model. In this study, main steam line break accident (MSLB) was chosen as a transient event for simulations and analyses. It was found that unexpected temperature and pressure variations can be found in vessel within a short period. In addition, the locations of loop inlets and the neutron shielding plate in downcomer may affect the core flow distributions and enhance core cooling rate in some parts of vessel.