百万千瓦级压水堆严重事故卸压阀高温瞬态分析

由于核电厂严重事故的恶劣工况，在卸压过程中严重事故卸压阀门可能会经历阀门无法承受的高温瞬态而导致不可用。本文在可能导致高压熔堆的事故序列中筛选出具有一定的包络性并包含各种典型严重事故现象的典型严重事故序列。针对该事故序列考虑严重事故管理中的开阀时间范围开展了高温瞬态计算，并针对重要的影响因素阀门开启时刻的稳压器水位开展分析。最终确定了百万千瓦级核电厂具备典型性及一定包络性的严重事故卸压阀工作条件，并得到了阀门开启前后阀门可能经历的最高流体温度及流体温度变化曲线，为严重事故卸压阀门的设备鉴定及功能应用提供了重要基础。 

Analysis of High-Temperature Transients in Severe Accident Depressurization Valve of 100 MW Pressurized Water Reactors

Due to the severe conditions in severe accidents of the nuclear power plants, the depressurization valves may experience a high temperature transient that the valves cannot withstand and may fail during the depressurization process. In this paper, the typical severe accident sequences that have a certain envelope and contain various typical severe accident phenomena are selected from the accident sequences that may lead to high-pressure melt ejection accident. According to the accident sequence, the high-temperature transient calculation was carried out considering the valves opening time range in severe accident management, and the water level of the pressurizer at the time of valve opening was analyzed for important influencing factors. Finally, the working conditions of the 100 MW nuclear power plant severe accident depressurization valves with typical and certain envelope characteristics are determined, and the maximum possible temperature and the variation temperature curve of fluid passing through the valves before and after valve opening are provided. It provides an important basis for equipment identification and function application of depressurization valves in severe accidents.