THERMAL HYDRAULIC ANALYSIS IN REACTOR VESSEL INTERNALS CONSIDERING IRRADIATION HEAT

摘要

The present study is to evaluate flow and temperature distributions in the APR1400 reactor vessel internals (RVIs) considering irradiation heat using the computational fluid dynamics code. The analysis is performed using a simplified reactor core model and the one-quarter geometry model that is postulated to be the flow symmetry condition, to calculate more effectively. The axial power density at the beginning of cycle (BOC), middle of cycle (MOC) and end of cycle (EOC) conditions is used as inputs to the CFD analysis, and velocity and temperature distributions are calculated on the four cross-sections of the reactor vessel (RV): lower support structure (LSS), core shroud (CS), upper part of the core and hot/cold leg center line. This method established the effect of a variation of the flow according to BOC, MOC and EOC conditions. The results of each model show the similar patterns in the flow distributions, however, the little difference appears in the temperature distributions under the operating conditions. The results of CFD analysis for the surface temperature distributions on the internals can be used for boundary conditions to perform stress analysis of the reactor vessel internals for the APR1400.