反应堆内熔融物冷却的三维数值模拟研究

目前国际上普遍采用堆芯熔融物压力容器内滞留（IVR）策略来缓解严重事故后果。本文基于日本应用能源研究所开发的核电厂事故分析程序SAMPSON，对其压力容器内熔融物冷却分析（DCA）模块进行改进，增加了熔池内金属和氧化物分层模型，开发了熔融物三维直角坐标网格与压力容器三维曲面坐标的交界面几何参数前处理程序，改进了压力容器外冷却的传热关系式。通过AP1000核电机组严重事故下的IVR对改进后的程序进行分析验证，并与实验结果进行对比。结果表明，改进后的SAMPSON程序可对核电厂严重事故下下封头内的熔融物冷却滞留开展有效的模拟分析。

Research on 3D Simulation of Core Melt Cooling in Reactor

At present, in-vessel retention (IVR) strategy is widely used in the world to mitigate the consequences of severe accidents. Based on the nuclear power plant accident analysis program SAMPSON developed by the Applied Energy Research Institute of Japan, the debris cooling analysis (DCA) module of SAMPSON program was improved, the stratified model of ceramic layer and metallic layer in molten pool was added, the pre-processing program for interface geometric parameters between 3D Cartesian meshes of melt and 3D surface coordinates of pressure vessel was developed, and the heat transfer relationship of the outer surface of the pressure vessel was improved. The improved program was verified by the IVR under the severe accident of the AP1000 nuclear power plant, and the calculated results were compared with experimental results. The results show that the improved SAMPSON program can effectively simulate and analyze the cooling and retention of melt in the lower head for nuclear power plant under severe accident.