临界事故报警系统的相似性  

Similarity analysis applied to nuclear criticality accident alarm systems

作　　者：徐源 江世航 杨海峰 易璇 邵增 Xu Yuan;Jiang Shihang;Yang Haifeng;Yi Xuan;Shao Zeng(China Nuclear Power Engineering Co.Ltd,Beijing 100840,China;Department of Engineering Physics,Tsinghua University,Beijing 100084,China)

机构地区：[1]中国核电工程有限公司,北京100840 [2]清华大学工程物理系,北京100084

出　　处：《强激光与粒子束》2024年第8期131-139,共9页High Power Laser and Particle Beams

摘　　要：为了确定用于场所监测的临界事故报警系统合适的报警阈值,需选用相似的基准实验进行验证。根据设备室临界事故报警系统的特征,构建了简易模型和具有代表性的包含多个设备的虚拟设备室模型。针对固定源问题,在蒙卡程序(RMC)中实现了基于微分算符抽样法计算敏感性系数的功能。随后,运用敏感性和不确定度分析方法对系统间的相似性进行了研究,并深入分析了影响相似性的因素。计算分析结果显示,对于简易模型,源项能谱和混凝土材料对系统间的相似性有较大影响,探测器与内侧墙面之间的混凝土厚度对相似性有一定影响,而源项的几何位置对相似性的影响较小,乏燃料成分对相似性的影响可以忽略不计。根据本文提出的相似性分析流程进行计算得出,简易模型与虚拟设备室模型的相似性较高,基于简易模型的研究结论适用于虚拟设备室模型,可为工程上的临界报警系统相似性研究提供参考。To determine the alarm threshold for criticality accident alarm systems(CAASs)used in facility monitoring,it is necessary to select appropriate benchmark experiments for validation.This paper constructs a simplified model and a representative virtual equipment room model,taking into consideration the characteristics of CAASs in the equipment room.The functionality of calculating sensitivity coefficients using the differential operator sampling approach in the Monte Carlo code RMC was implemented to solve the fixed source problem.Following that,a sensitivity and uncertainty analysis was conducted to examine the similarities between systems and explore the factors influencing them.The results indicate that the neutron source term spectrum and the concrete material significantly affect the similarity between systems.Additionally,the thickness of the concrete between the detector and the inner wall has a moderate influence on similarity,whereas the geometric position of the source term has a negligible impact.The impact of the spent fuel composition on similarity can be neglected.Based on the similarity analysis procedure proposed in this study,it is concluded that the simplified model exhibits a relatively high similarity to the virtual equipment room model.Hence,the research conclusions based on the simplified model are applicable to the virtual equipment room model,offering valuable insights for similarity studies of CAASs in engineering.

关 键 词：固定源相似性 敏感性分析 不确定度 临界事故报警系统 

分 类 号：TL731[核科学技术—辐射防护及环境保护]