压水堆大修下行工况冷却剂主要辐解产物计算研究  

Research on Calculation of Coolant Radiolysis Products in Operating Conditions during the Shutdown of PWRs

作　　者：李富海 林蕴良 林子健 林根仙[1] 郭子方 方军 林铭章[2] Li Fuhai;Lin Yunliang;Lin Zijian;Lin Genxian;Guo Zifang;Fang Jun;Lin Mingzhang(Suzhou Nuclear Power Research Institute Co.,Ltd.,Suzhou,Jiangsu,215008,China;School of Nuclear Science and Technology,University of Science and Technology of China,Hefei,230027,China;Institute of Nuclear and New Energy Technology,Tsinghua University,Beijing,100084,China)

机构地区：[1]苏州热工研究院有限公司,江苏苏州215008 [2]中国科学技术大学核科学技术学院,合肥230027 [3]清华大学核能与新能源技术研究院,北京100084

出　　处：《核动力工程》2023年第3期202-209,共8页Nuclear Power Engineering

摘　　要：压水堆大修时活化腐蚀产物源项控制是降低集体剂量最有力的手段,冷却剂辐解的影响必须予以考虑。本文基于水辐解反应动力学原理,构建了冷却剂辐解动力学模型,根据该模型计算得到了主要辐解产物H_(2)O_(2)、O_(2)和H_(2)在各工况的生成情况,并讨论了微观反应机理。结果表明:①在停堆下行过程中,冷却剂温度从310℃逐步下降到60℃,溶解氢浓度逐步降为0,一回路从还原性转为氧化性,H_(2)O_(2)和O_(2)的生成显著上升;②温度、B/Li浓度、溶解氢浓度、H_(2)O_(2)和O_(2)初始浓度等多种因素均会影响辐解产物的浓度;③H_(2)O_(2)和O_(2)是相互促进生成的关系,H_(2)可以显著抑制H_(2)O_(2)和O_(2)的生成,但高浓度的H_(2)O_(2)会保护H_(2)免遭·OH的消耗。本文研究结果将为压水堆大修下行工况参数的选择以及活化腐蚀产物源项控制提供参考和指导。The control of radioactive source of the activated corrosion products during the shutdown of PWRs is one of the most effective means to reduce the CRE.The effect of coolant radiolysis should be taken into account.In this paper,a coolant radiolysis kinetic model was developed based on water radiolysis reaction kinetics.The main radiolysis products such as H_(2)O_(2),O_(2)and H_(2) under different conditions were obtained through the kinetic calculations.The reaction mechanism was also discussed.The results showed that:①during the shutdown,as the temperature of coolant decreases from 310℃to 60℃,and the concentration of dissolved H_(2) decreased to 0,the coolant changes from reductive to oxidative.The radiolysis generation of H_(2)O_(2)and O_(2)is significantly promoted;②the generation of radiolysis products is affected by the chemical parameters,such as concentrations of B/Li,dissolved H_(2),dissolved O_(2)and H_(2)O_(2);③the generation of H_(2)O_(2)and O_(2)are mutually promoted by each other.The presence of H_(2) can inhibit the generation of H_(2)O_(2)and O_(2)to some extent.The presence of high concentration of H_(2)O_(2)will protect H_(2) from the consumption of·OH.The results in this paper may provide important references and guidances for the selection of operating parameters under different conditions during the shutdown of PWRs and the control of activated corrosion products.

关 键 词：压水堆 大修 冷却剂 辐解产物 

分 类 号：TM623.7[电气工程—电力系统及自动化] TL77[核科学技术—辐射防护及环境保护]