燃耗信任制方法在临界安全分析中的应用

Application of Burnup Credit Method in Critical Safety Analysis

采用燃耗信任制(BUC)方法及相关程序系统(APOLLO-2、DARWIN和CRISTAL)对不同辐照历史的燃料组件进行敏感性分析。结果表明:随着温度上升、硼浓度增大,乏燃料组件的中子增殖系数也将增大;燃耗信任制方法分析中,为了得到偏于保守的结果,考虑了核素成分修正因子及其计算不确定性。本文还列出了针对某个基准问题的试验值和计算值的比较。采用燃耗信任制方法对不同的轴向燃耗分布的组件进行临界计算,并进行了比较。

The project is a part of STC partnership of CEA-CAEA Co-operation Protocol in the peaceful uses of nuclear energy.This paper mainly presents BUC(BURNUP CREDIT) method and related computer code package(APOLLO-2,DARWIN and CRISTAL).By using these codes,sensitivity analysis for main physics parameters(including fuel temperature,moderator temperature,critical boron concentration and etc.) of fuel assembly in different irradiation conditions is calculated.The result shows that the neutron multiplica-tion factor will increase as the increasing of temperature and boron concentration.In order to consider the BUC method conservatively,the isotopic correction factor and its calculation uncertainty are taken into ac-count.Then,the paper lists the comparison of the results between calculation and experiment.Finally,this paper gives the analysis of BUC method according to five different axial burnup profiles.