基于电流组分分离模型的钒SPND伽玛效应计算方法和实验验证  

Research on numerical method and experimental verification of the vanadium SPND gamma effect based on current component separation model

作　　者：周遥 曹良志[1] 刘宙宇[1] 王立鹏[2] 邵睿智 贺清明[1] 吴宏春[1] ZHOU Yao;CAO Liangzhi;LIU Zhouyu;WANG Lipeng;SHAO Ruizhi;HE Qingming;WU Hongchun(School of Nuclear Science and Technology,Xi'an Jiaotong University,Xi'an 710049,China;State Key Laboratory of Intense Pulsed Radiation Simulation and Effect,Northwest Institute of Nuclear Technology,Xi'an 710024,China)

机构地区：[1]西安交通大学核科学与技术学院,西安710049 [2]西北核技术研究所强脉冲辐射环境模拟与效应国家重点实验室,西安710024

出　　处：《核技术》2024年第9期85-92,共8页Nuclear Techniques

基　　金：国家自然科学基金(No.11735011,No.U2067209)资助。

摘　　要：钒自给能中子探测器(Self-Powered Neutron Detector,SPND)在核反应堆混合辐射场中会产生显著的γ噪声电流,从而影响中子通量测量和堆芯在线监测的准确性。针对钒SPND的γ效应,根据探测器响应机理建立了电流组分分离模型,并构建了脉冲研究堆堆内SPND电流计算方法。基于不同电流组分的时间特性,利用200 kW辐照腔的停堆衰减测量实验量化了瞬发γ电流分量,电流组分分离模型在计算钒探测器稳态电流和稳态电流瞬发分量方面与实验数据吻合良好。通过对商用压水堆甩负荷瞬态试验过程的钒SPND模拟,进一步验证了探测器数值模型的动态响应跟踪和瞬发γ电流模拟能力。研究表明:在理论计算和测量分析中均需要考虑钒SPND的γ效应,在实际堆芯中,γ响应存在不同电流组分之间的相互补偿作用。[Background]The vanadium self-powered neutron detector(SPND)generates significant gamma noise current in the mixed radiation field of a nuclear reactor,which adversely affects the accuracy of neutron flux measurements and online monitoring of reactor core.[Purpose]This study aims to explore the gamma effect of vanadium SPND through a combination of theoretical calculation method and experimental verification.[Methods]First of all,a current component separation model was established according to the vanadium detector response mechanism,and the current calculation method of SPND in the pulsed research reactor was constructed.Then,multistep Monte Carlo method was used to realize the coupling calculation of the core scale and the detector signal.Based on the temporal characteristics of different current components,the prompt γ current component was quantified by using the shutdown attenuation measurement experiment at the 200 kW radiation chamber of a research reactor.Finally,the measured signals were used to verify the sensitivity component separation model,and the dynamic response tracking and prompt γ current simulation capabilities of the detector numerical model were further verified by the vanadium SPND simulation of the commercial pressurized water reactor load rejection test process.[Results]The established vanadium SPND calculation model can be used to effectively distinguish the detector response current component with a relative deviation of 2.27% for steady-state current calculation,and the calculated results agree well with the experimental data in terms of calculating the steady-state current and the prompt component of the steady-state current for the vanadium detector.[Conclusions]This study has shown that the gamma effect of vanadium SPND needs to be considered in both theoretical calculations and measurement analysis,and there is a mutual compensation effect among different current components in the gamma response of the actual reactor core.

关 键 词：钒自给能中子探测器 γ响应 电流组分分离模型 研究堆验证 

分 类 号：TL816[核科学技术—核技术及应用]