反冲释放对反应堆活化腐蚀产物源项的影响研究  

Study on recoil release on the source term of activated corrosion product in reactor

作　　者：谭琳 张竞宇[1] 赵晓泽 肖懿鑫 王娟娟 于虓 倪王慕鸿 TAN Lin;ZHANG Jingyu;ZHAO Xiaoze;XIAO Yixin;WANG Juanjuan;YU Xiao;NI Wangmuhong(School of Nuclear Science and Engineering,North China Electric Power University,Beijing 102206,China)

机构地区：[1]华北电力大学核科学与工程学院,北京102206

出　　处：《核技术》2023年第10期78-84,共7页Nuclear Techniques

基　　金：国家磁约束核聚变能发展研究专项(No.2019YFE03110000,No.2019YFE03110003)资助。

摘　　要：中子与靶核碰撞时引起的靶核反冲释放,对于反应堆活化腐蚀产物源项分析有非常重要的影响。对于使用水冷方式的反应堆,在辐照区反冲释放可使活化腐蚀产物离开壁面进入到冷却剂中,并随冷却剂迁移到非辐照区,使非辐照区的设备也带有放射性。本文研究了反冲释放在反应堆内的作用方式,建立了反冲释放的计算模型和程序模块,并集成到活化腐蚀产物源项分析程序CATE中,利用改进后的CATE程序,计算分析了堆芯与蒸汽发生器中主要的活化腐蚀产物核素^(58)Co与^(60)Co在考虑反冲释放前后的数值,明确了反冲释放效应的影响程度。计算结果表明:考虑反冲释放前后堆芯处^(58)Co与^(60)Co活度的比值有所下降,而在蒸汽发生器中的比值则有所上升;反冲释放的总作用概率与腐蚀产物层厚度相关,会随着反应堆的运行而逐渐降低,反应堆运行初期作用概率的数量级在10^(-1),对活化腐蚀产物的迁移有显著影响,100 d后作用概率的数量级下降到10^(-3),对活化腐蚀产物源项的影响较小。[Background]The recoil release caused by the collision of a neutron with a target nucleus has a significant impact on the analysis of activated corrosion product sources in a reactor.In water cooled reactors,a recoil release in the irradiated area can cause the activation corrosion products to leave the wall surface and enter the coolant,which then migrates to the non-irradiated area with the flow of coolant,thereby making the non-irradiated equipment also radioactive.[Purpose]This study aims to analyze the influence of recoil release on the source term of activated corrosion product in reactor.[Methods]Based on the investigation of the mode of action of recoil release in a reactor,a calculation model and a program module for recoil release was established and integrated into the CATE program.Then,the effects of recoil release on the concentrations of activation corrosion products in the nuclear reactor were analyzed by using two approaches,one involved specifying a recoil release probability,while the other involved dynamically calculating the recoil release probability.Finally,values of the main activated corrosion products nuclides^(58)Co and^(60)Co in the core and steam generator before and after considering recoil release were calculated,and the impact of recoil release on the activation corrosion products and its implications for the actual operation of the reactor were explored.[Results]The calculation results indicate that the recoil release probability decreases from 45%at the beginning of the simulation to 0.3%at the end of the simulation.However,the variation pattern of the activity ratio of^(58)Co and^(60)Co in the core and steam generator remains the same as that without recoil release.The activity ratio is 91%and 203%respectively,compared to the case without recoil release.[Conclusions]The total probability of recoil release is related to the thickness of the corrosion product layer and gradually decreases with the operating time of the reactor.

关 键 词：水冷堆 活化腐蚀产物 反冲释放 CATE程序 计算模拟 

分 类 号：TL99[核科学技术—核技术及应用]