摘要
压水堆核电厂在严重事故下将发生堆芯熔化事故而形成熔融池。形成熔融池的过程具有很大的不确定性,这影响到反应堆压力容器熔融物堆内滞留(IVR)策略的有效性。本工作以AP1000核电厂两层IVR模型为研究对象,对成功实施反应堆压力容器外部冷却(ERVC)的假想严重事故进行了熔融池参数不确定性分析,包括参数的敏感性分析和使用拉丁超立方抽样的概率分析。结果表明:衰变功率对IVR评价参数影响最大,应采取措施(如上堆腔注水)尽量延缓堆芯熔化的时间;熔融物中不锈钢的质量将对金属层参数造成较大影响,可考虑在压力容器内布置牺牲性材料来减小金属层的集热效应;氧化物层外压力容器失效的概率仅为1.2%,但金属层外压力容器失效的概率高达20%。本结果对今后IVR策略研究和设计具有一定的指导意义,同时也为压水堆核电厂安全评审提供理论支持。
A molten pool comes into being after core damage under severe accident conditions in PWR plant. It has many uncertainty factors about the forming process of the molten pool, and this will affect the validity of in-vessel retention （IVR） strategy of reactor vessel. Based on the two-layer IVR model of AP1000, the study on the parameters uncertainty of molten pool under assumed severe accident conditions for external reactor vessel cooling （ERVC） was achieved, including sensitivity analysis and Latin hypercube sampling （LHS） probability analysis of the parameters. The results show that decay power has the essential effect on IVR evaluation parameters. Actions such as water injection from upper plenum should be taken to delay the core molten time. The mass of stainless steel in debris has great Some penalty materials could be placed in metal layer. The invalidation probability merely 1.2 reaches up research an plants. impact on parameters of molten metal layer. vessel to mitigate the heat focus effect of the of vessel outside of molten ceramic layer is merely 1.2%, but the invalidation probability of vessel outside of molten metal layer to 20%. This study has certain directive significance on future IVR strategy d design, and also provides theoretical support to safety evaluation of PWR plants.
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2012年第1期37-42,共6页
Atomic Energy Science and Technology
关键词
严重事故
堆内滞留
敏感性分析
不确定分析
拉丁超立方抽样
severe accident
in-vessel retention
sensitivity analysis
uncertainty analysis
Latin hypercube sampling
