严重事故条件下安全壳响应模拟研究

压水堆核电厂发生严重事故期间，从主系统释放的蒸汽、氢气以及下封头失效后进入安全壳的堆芯熔融物均对安全壳的完整性构成威胁。以国内典型二代加压水堆为研究对象，采用MAAP程序进行安全壳响应分析。选取了两种典型的严重事故序列：热管段中破口叠加设备冷却水失效和再循环高压安注失效，堆芯因冷却不足升温熔化导致压力容器失效，熔融物与混凝土发生反应（MCCI），安全壳超压失效；冷管段大破口叠加再循环失效，安全壳内蒸汽不断聚集，发生超压失效。通过对两种事故工况的分析，证实了再循环高压安注、安全壳喷淋这两种缓解措施对保证安全壳完整性的重要作用。

Simulation Research on Containment Response under Severe Accident Condition

During the severe accident of pressurized water reactor, steam and hydrogen released from primary system, and core melt released to the containment after reactor pressure vessel (RPV) fails, all pose a threat to the integrity of the containment. The containment response of the domestic second generation pressurized water reactor was analyzed using MAAP code in the paper. Two severe accident conditions were selected. The first is hot leg middle break loss of coolant accident (LOCA) with the equipment cooling system (RRI) failure and the recirculating high pressure injection failure. The failure of recirculating high pressure injection leads to the insufficient cooling of core and the melting of core material. After RPV fails, the core melt falls into the cavity, and molten core concrete interaction occurs. Continuous gas release leads to the containment overpressure failure. The second is cold leg large break LOCA with the recirculation failure. The accumulation of steam leads to containment overpressure failure. Through the analysis of the two accident conditions, importances of high pressure injection and containment spray system are confirmed in ensuring the integrity of containment.