基于β因子法的核电DCS共因故障定量分析研究

Quantitative Analysis of the Common Cause Failure of the Nuclear Power DCS Based on theβ-factor

随着多重冗余的核电数字化仪控系统的逐步推广运用,共因故障成了不可忽视的重要失效模式。为解决共因故障的定量分析问题,本文从实际工程应用出发,根据假设给出了两种β因子的评估方法。基于可靠性框图(Reliability Block Diagrams,RBD),针对安全级核电DCS紧急停堆系统(Reactor Trip System,RTS)整理出了逻辑系统的失效模型,并给出包含共因故障的系统平均失效概率计算公式,带入实例进行计算分析。最后通过分析给出了有效降低共因故障的措施,可为核电DCS可靠性分析提供参考,具有重要的工程应用价值。

With the gradual popularization and application of multi-redundant digital instrumentation and control systems,common faults have become an important failure mode that cannot be ignored.In order to solve the problem of quantitative analysis of common cause failure,this paper starts from the practical engineering application and gives two evaluation methods ofβfactor based on the hypothesis.Based on the reliability block diagrams(RBD),the failure model of the logic subsystem is compiled for the safety-level nuclear power DCS emergency shutdown system(RTS),and the average failure probability of the system including the common cause failure is given.Calculate the formula and bring it into the instance for calculation analysis.Finally,the measures to effectively reduce common cause failures are given through analysis,which can provide reference for nuclear power DCS reliability analysis and have important engineering application value.