核电站中子能谱测量和评价  

Measurement and evaluation of neutron spectra in nuclear power plants

作　　者：王平全 杨竣凯 张辉[1] 任忠国 王仁生 张健[1] WANG Pingquan;YANG Junkai;ZHANG Hui;REN Zhongguo;WANG Rensheng;ZHANG Jian(National Institute of Metrology,Beijing 100029,China;Institute of Applied Electronics,China Academy of Engineering Physics,Mian-yang 621900,China;School of Radiation Medicine and Protection,Department of Medicine,Soochow University,Suzhou 215123,China;Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions,Suzhou 215123,China)

机构地区：[1]中国计量科学研究院,北京100029 [2]中国工程物理研究院应用电子学研究所,四川绵阳621900 [3]苏州大学医学部放射医学与防护学院,江苏苏州215123 [4]江苏省高校放射医学协同创新中心,江苏苏州215123

出　　处：《哈尔滨工程大学学报》2022年第11期1621-1629,共9页Journal of Harbin Engineering University

基　　金：国家重点研发计划(2017YFF0206205);中国计量科学研究院基础研究项目(AKYZZ2113).

摘　　要：针对中子周围剂量当量仪常规校准无法有效修正现场测量结果的问题,本文采用多球中子谱仪测量了秦山核电站不同反应堆厂房内多个位置的中子能谱。计算出多球中子谱仪的响应函数,并进行单能中子响应的实验刻度,采用最大熵算法、迭代算法和遗传算法3种算法对测量结果进行解谱,通过能谱推导出多种中子辐射参量进行解谱结果验证,对中子剂量仪LB6411和FHT762的直接测量结果进行现场测量修正。研究结果表明:3种算法的中子能谱吻合较好,反解计数率与测量计数率在不确定度范围内一致,表明测量过程和解谱结果可靠;最大熵算法和迭代算法的解谱结果最好,应优先考虑,遗传算法稍差,适用于辐射环境未知的情况;根据能谱结果推算出的中子周围剂量当量H^(∗)(10)不确定度为8%~10%;与能谱结果相比,FHT762直接测量结果偏大25%~61%,LB6411结果偏小4%~21%,证实了能谱方法对于提高核电站现场H^(∗)(10)测量精确度的可行性。A multisphere neutron spectrometer is used to measure the neutron spectrum at several locations in differ-ent reactor plants of the Qinshan nuclear power plant to address the ineffectiveness of routine calibration of neutron ambient dose equivalent meter in correcting the onsite measurement results.The response function of the multi-sphere neutron spectrometer is calculated,and the experimental calibration of the monoenergetic neutron response is conducted.Three algorithms,namely the maximum entropy,iterative,and genetic algorithms,are used to reveal the spectrum of the measurement results.A variety of neutron radiation parameters are deduced from the spectrum for the verification of the spectrum results,and the direct measurement results of the neutron dosimeter LB6411 and FHT762 are corrected for the onsite measurements.The following results are presented.The neutron spectra of the three algorithms agree well,and the folding count rates agree with the measured count rates within an uncertainty range,indicating that the measurement process and the spectrum results are reliable.The maximum entropy and iterative algorithms have the best spectrum results and should be considered preferentially.Meanwhile,the genetic algorithm is slightly worse but is suitable for the case with an unknown radiation environment.The uncertainty of the neutron ambient dose equivalent H^(∗)(10)derived from the energy spectrum results is 8%~10%.The direct measurement results of FHT762 are 25%~61%larger,and the LB6411 results are 4%~21%smaller compared with the spectrum results.This finding confirms the feasibility of the spectrum method to improve the accuracy of H^(∗)(10)measurement onsite in nuclear power plants.

关 键 词：多球中子谱仪 核电站 中子能谱 响应函数 周围剂量当量 最大熵算法 迭代算法 遗传算法 

分 类 号：O571.54[理学—粒子物理与原子核物理]