基于格林函数节块法的物理与热工-水力耦合方法研究

Study of Neutronics and Thermal-Hydraulics Coupling Methodology Based on Nodal Green's Function Method

开发了三维物理与热工-水力耦合的PWR堆芯瞬态分析程序NGFMN-K/COBRA-Ⅳ/COBRA-Ⅳ(NCC)。少群时空中子动力学计算采用格林函数节块法程序NGFMN-K,隐式耦合子通道程序COBRA-Ⅳ实现瞬态计算。采用P10H8B功率重构方法给出热组件栅元功率分布,耦合另一个COBRA-Ⅳ程序模块,进行热组件子通道分析得到安全参数。对NEACRP-L-335C1弹棒基准问题的计算表明,NCC程序的计算结果与参考结果符合很好,说明程序计算正确,可用于评估事故结果。

A coupled three-dimensional neutronics and thermal-hydraulics code NGFMN- K/COBRA-IV/COBRA-IV （NCC） was developed for PWR core transient analysis. The neutronics model was the NGFMN K code based on nodal Green＇s function method. One COBRA-IV sub-channel code was coupled with NGFMN-K implicitly for core transient calculation. Through integrating the other COBRA-N code for sub-channel calculation on hot assemble, the code system was capable of evaluating safety-related parameters. The pin power distribution in hot assemble was constructed by P10H8B pin power reconstruction method. Numerical evaluation results on the NEACRP-L-335 C1 rod ejection benchmark problem show that the calculation results of NCC code agree well with reference solutions. NCC is capable of accident analysis.