基于ASTEC程序对事故下碘和铯行为特性研究  

The Characteristic of Source Term Iodine andCesium Under Severe Accident with ASTEC Code

作　　者：胡文超 张盼 毕金生 段军 赵传奇 王政辉 依岩 HU Wenchao;ZHANG Pan;BI Jinsheng;DUAN Jun;ZHAO Chuanqi;WANG Zhenghui;YI Yan(Nuclear and Radiation Safety Center,MEE,Beijing 100082,China;China National Nuclear Research Institute Co.,Ltd.,Shenzhen of Guangdong Prov.518028,China)

机构地区：[1]生态环境部核与辐射安全中心,北京100082 [2]中广核研究院有限公司,广东深圳518028

出　　处：《核科学与工程》2020年第5期904-910,共7页Nuclear Science and Engineering

基　　金：反应堆严重事故分析程序研发(2019YFB1900705)。

摘　　要：核电站发生事故最严重的后果是放射性裂变产物弥散到环境中,其中放射性裂变产物碘(I)和铯(Cs)在事故工况下具有典型的特点,本研究假设一回路管道发生破裂事故,使用事故源项评估程序(ASTEC)构建一回路冷却剂流通管道控制体结构模型,并设置边界条件,在给定热源温度工况下,研究了放射性裂变产物源项在控制体内分布情况和化合物状态。研究结果表明,I、Cs是产生放射性的主要来源,I主要形成Cs2I2以及气态的I,Cs主要形成Cs2(OH)2、Cs2I2这两种化合物,由于I、Cs多以挥发性的气体形式存在,在事故工况下极易在安全壳空间内扩散,进行更为复杂的反应,因此本研究对I、Cs在冷却剂管道中的迁移特性进行研究为事故工况下I、Cs的去除提供了理论支持。The most serious consequence of reactor severe accident is that radioactive fission products are dispersed into the environment in the nuclear power plant.The fission product iodine and cesium have typical characteristics under severe accident.Base on the hypothetical mode of serious rupture accident in the primary circuit.we use the ASTEC code to build the configuration model and setup the boundary conditions,Then ASTEC code is used to calculate and study the distribution of fission product sources in the controlled body and the state of the compound under the constant heat source temperature condition in the nuclear power plant.The research results show that iodine and cesium are the main sources of radioactivity,iodine forms Cs2I2 and gaseous I,cesium mainly forms two compounds Cs2(OH)2 and Cs2I2.Because I and Cs mostly exist in the form of volatile gases,they are easy to diffuse in the containment space under the severe accident condition and carry out more complex chemical reactions.Therefore,the study on characteristics of I and Cs in the coolant pipeline provides theoretical support for the removal of I and Cs under the accident condition.

关 键 词：ASTEC 严重事故 源项 碘 铯 

分 类 号：TL364.4[核科学技术—核技术及应用]