RPV下封头熔融池换热特性数值模拟研究  

Numerical simulation on heat transfer in RPV lower head corium pools

作　　者：朱光昱 闵金坤 靖剑平 王昆鹏 刘福东 ZHU Guangyu;MIN Jinkun;JING Jianping;WANG Kunpeng;LIU Fudong(Center for Nuclear and Radiation Safety,Ministry of Ecology and Environment,Beijing 100082,China;State Environmental Protection Key Laboratory of Nuclear and Radiation Safety Regulatory Simulation and Validation,Beijing 102488,China;China Nuclear Power Engineering Co.,Ltd.,Beijing 100840,China;Department of Engineering Physics,Tsinghua University,Beijing 100084,China)

机构地区：[1]生态环境部核与辐射安全中心,北京100082 [2]国家环境保护核与辐射安全审评模拟分析与验证重点实验室,北京102488 [3]中国核电工程有限公司,北京100840 [4]清华大学工程物理系,北京100084

出　　处：《核技术》2022年第1期97-102,共6页Nuclear Techniques

基　　金：国家重点研发计划(No.2018YFB1900100、No.2018YFB1900102)资助。

摘　　要：熔融物堆内滞留(In-vessel Retention,IVR)指的是在核电厂严重事故发生后,通过在压力容器和保温层间隙注入冷却水防止压力容器熔穿失效。本文基于COMSOL Multiphysics软件建立了一个流-热-固耦合计算模型,对IVR技术作用下的反应堆压力容器(Reactor Pressure Vessel,RPV)下封头双层熔融池的演变过程进行了仿真研究。当前模型计算结果表明:在稳态分层的状态下,与氧化物层接触的下封头未发生明显的熔化,与金属层接触的下封头会发生明显的熔化,但在被冷却条件下依然可以保持压力容器的完整性。[Background]In-vessel Retention(IVR)refers to the prevention of pressure vessel melt-through failure by injecting cooling water into the gap between the pressure vessel and the heat insulation layer during a serious accident in a nuclear power plant.When the double-layer corium pool formed in the lower head of the reactor pressure vessel(RPV),the lower head in contact with the metal layer may fail due to the heat accumulation in the metal layer.[Purpose]This study aims to build a computational model by numerical simulation to investigate the thermal hydraulic characteristics of the double-layer corium pool in pressurized water reactor(PWR).[Methods]Based on the design parameters of current large third generation PWR,the calculation model of the fluid-heat-solid coupling double-layer corium pool was established by using COMSOL Multiphysics code.The upper surface of metal layer was considered as the radiation boundary condition,and the outside of the lower head was set as forced convection cooling.[Results]Simulation results show that a natural convection main flow forms in the oxide layer in stable two-layer corium pool,and a mass of vortexes exist in the metal layer.The lower head in contact with the oxide layer does not melt obviously whilst significant melting occurs in the lower head area in contact with the metal layer due to the rising temperature.The completeness of the pressure vessel is maintained under normal cooling conditions.[Conclusions]The IVR design is proved efficient to protect the pressure vessel form melt failure during a serious accident.

关 键 词：熔融物堆内滞留 严重事故 熔融池 

分 类 号：TL334[核科学技术—核技术及应用]