基于RMC的微观截面参数化

Micro cross-section parameterization based on RMC code

为了进行堆芯计算,需要通过组件计算提前构建少群截面参数库。传统确定论的组件截面参数化方法针对宏观截面进行截面参数化,但这种方式不仅需要考虑多种物理状态参数,而且需要考虑历史效应对截面的影响。提出了基于核素微观截面的蒙卡程序参数化方法,该方法可以消除燃耗历史的影响,且考虑的物理状态仅为燃耗深度以及材料温度。利用蒙卡程序产生组件截面参数库耦合堆芯程序进行堆芯计算,首先用蒙卡程序同时统计对应状态点下的核素密度以及核素少群微观截面,再利用核素微观截面进而获得宏观截面进行后续堆芯计算。为了验证方法正确性,构造了一个自定义的压水堆模型,计算结果与连续能量蒙卡计算结果符合良好。

To perform realistic core calculations,few-group neutron cross-sections library by functions of burn-up and thermal hydraulics parameters should be prepared in advance.Traditional deterministic parameterization process is based on the macro cross-section.However,this method should consider the historical effect of some physical states,which increases the number of calculation branches.Thus,this paper proposes a new parameterization process based on the micro cross-section of nuclide.This method effectively eliminates the historical impact.Therefore,only burn-up and material temperature need to be considered.The calculation process is performed by RMC code.Firstly,all of material nuclides micro cross-section and nuclides density is calculated.Then,macro cross-section is obtained by the micro cross-section lib.To test the method accuracy,a self-design pressurized water reactor model is built.The test results agree well with the reference results calculated by RMC full core calculation.