基于粒子法的新型堆芯捕集器关键现象 数值模拟研究

In order to establish a prediction method for the entire process of a novel core catcher following lower head failure of the pressure vessel, and to provide an additional approach for the optimization analysis of the novel core catcher, Incompressible Smooth Particle Hydrodynamics (ISPH) method was used to predict the behavior of the core melt in the novel core catcher. Through numerical simulations, a series of behaviors under severe accident conditions in nuclear reactors are investigated, including: jet erosion of core melt, accumulation of melt on the stainless steel plate, melting of the stainless steel plate due to the corium's sensible heat and decay heat, flow characteristics of melt in concrete channels, molten corium-concrete interaction, and coupled heat transfer inside and outside the novel core catcher. The predicted heat fluxes and ablation rates show good agreement with experimental data and results from integrated severe accident analysis codes. Thus, this study holds significant engineering application value for optimizing the design of novel core catchers in nuclear reactors.