采用一体化严重事故分析工具,建立包括主热传输系统、专设安全设施、安全壳系统的AP1000的事故分析模型。根据AP1000概率安全评价选取典型事故序列,同时叠加相关安全系统失效的严重事故进程进行模拟,结果表明,中破口始发严重事故压力容器内会产生624kg的氢气,安全壳隔间有氢气燃烧的风险。同时,建立氢气控制系统模型,选取热段中破口始发(MB-LOCA)的严重事故序列,分析氢气控制系统的消氢效果,结果表明,氢气控制系统可以有效地将氢气浓度控制在安全限值以内,采用64个点火器叠加2个非能动氢气复合器(PARs)可以有效降低点火次数。
AP1000 model, including Reactor Coolant System(RCS), Engineering Safety Features (ESFs), and containment, is built by using the integrated severe analysis code. According to AP1000 Probability Risk Analysis (PRA), several typical sequences are selected. The accident progressions are analyzed and hydrogen sources are investigated. It indicates that 624kg hydrogen will be generated in pressure vessel induced by MB-LOCA. The model of hydrogen control system, which consists of 64 glow-up igniters and two Passive Autocatalytic Recombiners (PARs), is built to analyze the effectiveness of removing hydrogen and the combustion modes are identified by the Shapiro triangular diagram. The results show that hydrogen concentration could be controlled within the safety limits by using 64 glow-up igniters and two PARs to protect the containment integrity from hydrogen deflagration or detonation.
