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本文对广泛应用于第三代压水堆的严重事故缓解措施——熔融物堆内滞留(IVR)进行了历史回顾。IVR策略最早源自于第二代反应堆Lovissa VVER-440的改进设计,以应对堆芯熔化事故。随后,IVR策略被应用于许多新设计的反应堆,如西屋的AP1000、韩国的APR1400以及中国的先进压水堆CAP1400和华龙一号。对IVR策略有效性影响最大的因素分别为堆内堆芯熔化进程、熔融物加载于压力容器壁面的热流密度和压力容器外部冷却。对于堆芯熔化进程,过去人们一直仅关注压力容器下腔室内熔池的换热行为。但通过回顾与分析,本文认为堆内的其他现象,如堆芯的降级和迁移、碎片床的形成及其可冷却性以及熔池的动态形成过程等,可能也会对熔池的最终状态及其作用于下封头的热负荷产生影响。通过对相关研究的回顾,本文希望找出IVR策略的研究中有待完善的部分,并据目前发展水平提出未来IVR研究的需求。
This article reviews the historical accidental melt retention (IVR), a serious accident mitigation measure widely used in the third generation PWR. The IVR strategy originated from the improved design of the Lovissa VVER-440, a second-generation reactor, to deal with a core melting accident. Subsequently, the IVR strategy was applied to many newly designed reactors such as Westinghouse AP1000, South Korea’s APR1400 and China’s Advanced PWR CAP1400 and Hualong No.1. The factors that have the most effect on the effectiveness of IVR strategy are the core melting process in the reactor, the heat flux of the melt loaded on the pressure vessel wall and the external cooling of the pressure vessel respectively. For the melting process of the core, in the past, people only paid attention to the heat transfer behavior of the puddle in the lower chamber of the pressure vessel. However, through reviewing and analyzing, this paper argues that other phenomena in the reactor, such as the degradation and migration of the core, the formation of the debris bed and its cooling ability, and the dynamic formation process of the molten pool, may also affect the final state of the molten pool and Its role in the next head of the heat load impact. Through reviewing the related research, this article hopes to find out the part to be improved in the research of IVR strategy and put forward the demand of future IVR research according to the current development level.