基于非均匀谱修正方法的熔盐堆少群截面计算  

Generation of the Few-Group Cross Sections for Molten Salt Reactors Based on Non-Uniform Spectra Modification Method

作　　者：戴明[1] 张奥 程懋松[1,2] Dai Ming;Zhang Ao;Cheng Maosong(Shanghai Institute of Applied Physics,Chinese Academy of Science,Shanghai,201800,China;University of Chinese Academy of Sciences,Beijing,101408,China)

机构地区：[1]中国科学院上海应用物理研究所,上海201800 [2]中国科学院大学,北京101408

出　　处：《核动力工程》2024年第5期62-70,共9页Nuclear Power Engineering

基　　金：中国科学院战略性先导科技专项资助。

摘　　要：针对熔盐堆高泄漏及强异质性特点,基于特征线方法(MOC)的全堆输运计算适用于熔盐堆临界计算。为权衡计算效率及精度,提出非均匀谱修正(nSM)方法为MOC全堆计算提供少群截面。该方法是一种嵌入式泄漏修正方法,即利用少群MOC全堆计算反馈的泄漏参数进行多群能谱计算,然后在线更新全堆计算的少群截面。针对熔盐实验堆(MSRE)二维全堆基准题,与蒙卡程序OpenMC连续能量计算结果对比,非均匀谱修正方法计算的k_(eff)偏差小于0.25%,全堆最大裂变率偏差为2.6%,位于相对裂变率仅0.04的堆容器节块,其计算结果明显优于使用组件计算能谱并群截面方案结果。计算分析表明,引入近似的非均匀谱修正方法具有较好精度,且能显著提高计算效率,是一种能为熔盐堆MOC全堆计算提供少群截面的可行方法。In view of the high leakage and strong heterogeneity of molten salt reactors,the whole-core transport calculation based on the method of characteristic(MOC)is suitable for the critical calculation of molten salt reactors.To balance computational efficiency and accuracy,the non-uniform spectra modification(nSM)method is proposed to generate the few-group cross sections for MOC whole-core calculations.This method is an embedded leakage modification method,which utilizes the leakage parameters obtained by the few-group MOC whole-core calculation for multi-group spectrum calculations,thereby online updating the few-group cross sections of the whole-core calculation.Compared with results from the continuous energy Monto Carlo code OpenMC for the MSRE two-dimensional whole-core benchmark problems,the k_(eff) errors calculated by nSM method are less than 0.25%and the maximum error of 2.6%in fission rate distributions occurs at the core can node with a relative fission rate of only 0.04,which are obviously better than those using the cross sections collapsed by the spectra calculated by assembly calculations.The results show that the approximate nSM method still has good accuracy,and could significantly improve the calculation efficiency.Therefore,nSM method could be a feasible method that provides few-group cross sections for the MOC whole-core calculation of molten salt reactors.

关 键 词：非均匀谱修正 熔盐堆 特征线方法(MOC) 全堆输运计算 少群截面加工 

分 类 号：TL329[核科学技术—核技术及应用]