严重事故下安全壳内裂变产物碘影响因素敏感性分析  

Analysis of Sentitivity of Fission Product Iodine in Containment to Various Factors under Severe Accidents

作　　者：胡文超 潘昕怿 张盼 赵传奇 孙海绪 依岩 Hu Wenchao;Pan Xinyi;Zhang Pan;Zhao Chuanqi;Sun Haixu;Yi Yan(Nuclear and Radiation Safety Center,Mnistry of Ecology and Environment,Beijing,100082,China;Harbin Engineering University,Harbin,100051,China)

机构地区：[1]生态环境部核与辐射安全中心,北京100082 [2]哈尔滨工程大学,哈尔滨150001

出　　处：《核动力工程》2021年第5期182-188,共7页Nuclear Power Engineering

基　　金：反应堆严重事故分析程序研发(2019YFB1900705)。

摘　　要：反应堆发生事故最严重的后果是放射性裂变产物弥散到环境中,为了研究严重事故工况下放射性裂变产物碘在安全壳内的分布特点,本研究假设核电厂已经发生严重事故,一回路裂变产物碘释放到安全壳内。使用事故源项评估程序(ASTEC)构建核电厂安全壳结构模型,并设置边界条件,计算了裂变产物碘在不同pH值、有无金属银注入和气相辐照工况下的化学形态、化学特性、分布情况以及不同化合物的变化趋势。研究结果表明,碱性环境下可以降低安全壳内挥发性碘的生成;银的存在可以增加液相中碘的捕获和降低碘的挥发;气相辐照环境可以提高气相CH3I和IOx的形成。本研究可以为严重事故工况下安全壳内放射性碘的去除提供支持。The most serious consequence of reactor accident is that the radioactive fission products are dispersed into the environment.To study the distribution characteristics of radioactive fission product iodine in the containment under severe accident conditions,this paper assumes that the fission product iodine is released from the primary system into the containment due to the occurrence of severe accident in the nuclear power plant(NPP).Then,using the accident source term evaluation code(ASTEC),this study builds a containment construction model for the NPP,sets the boundary conditions,and calculates the chemical form,chemical properties,distribution,and change trends of different compounds,of the fission product iodine under different pH values,with or without silver(Ag)injection and under gaseous radiation conditions.The results show that the production of volatile iodine in the containment can be inhibited under alkaline conditions;the silver can promote the iodine trap in the liquid phase and reduce the iodine volatility;and the gaseous radiation environment can promote the formation of gaseous CH3I and IOx.As a result,this study can provide guidance for the removal of radioactive iodine in the containment under serious accidents.

关 键 词：ASTEC 严重事故 碘 pH AG 气相辐照 

分 类 号：TL364.4[核科学技术—核技术及应用]