核电厂PSA中事故序列后果分析方法研究

Algorithms of Consequence Analysis for PSA in Nuclear Power Plant

在核电站PSA事故序列后果求解过程中,为减小事件树转换成故障树的规模,需对事故序列的布尔表达式进行简化。首先,引入"三步法",即在事件树转换成后果故障树前,先形成以始发事件和功能事件为节点的故障树;然后,利用FAUNET规则对该故障树进行化简;最后,用始发事件和功能事件的实际输入替代这些节点。在FAUNET简化规则基础上,增加1条新的吸收规则用于简化事故序列后果故障树的某些特殊结构。在FDS团队开发的大型可靠性/概率安全分析软件RiskA平台上对上述方法进行了实现,并经大量实例测试证明了这种处理方法的有效性。

In the process of consequence analysis for PSA, simplification on fault tree converted from event trees was done in order to reduce the scale of fault trees. A threestep algorithm was presented based on the theory of consequence analysis. In addition, considering the inconvenience of FAUNET for some specific consequence fault tree structure, a new absorption algorithm was introduced. The algorithms were implemented in the home-developed PSA code RiskA. The comparative analysis of some examples shows that the methods are effective.