核安全级仪控软件可靠性评估模型构建

摘要

为了对核安全级仪控系统软件可靠性进行定量评估，研究依照贝叶斯网络建模步骤进行模型建设的方法。对国际上几种主要核安全级仪控系统标准体系进行对比分析，构建核安全级系统软件可靠性评估综合模型和子模型，使用贝叶斯公式对模型可靠性进行量化计算和评估，提出通过衡量模型各节点的敏感度验证模型建立的合理性。实现运用贝叶斯网络方法，通过对系统因素关系分析，结合专家定性判断，对复杂系统进行模型构建，同时提供对系统内不确定因素进行定性与定量相结合的预测和验证的方法。%In this paper, the model construction method based on Modeling Steps of Bayesian Belief Network ( BBN) is studied in order to quantitatively analyze the software reliability in nuclear safety class digital instrumentation and control system ( D-I&C) .Comparative analysis was performed on major international nuclear safety class D-I&C soft-ware standard systems, and comprehensive Evaluation Models of D-I&C Software Reliability and sub-models were constructed.Quantitative calculation and evaluation were performed for the models by Bayesian function, verifying the rationality of the models by sensitivity analysis on the nodes in the network.In the application of the BBN method, the relations of elements in a system are analyzed in combination with the qualitative judgment made by professionals and experts, and the models for a complicated system were constructed.As a result, it is concluded that the indefinite ele-ments in the network can be predicted and verified by qualitative and quantitative methods.