核电厂备用系统可靠性模型及其参数评估方法

Standby System Reliability Model of the Neclear Power Plant and Its Parametric Evaluation Methods

由于同时存在备用应力和需求应力,导致了备用设备可靠性模型的多样化。本文首先给出了只考虑备用失效和需求失效的基本模型,并对在可靠性和风险评估中使用不同模型所带来的差异进行了研究,总结了两种基本模型的特点;然后,对同时考虑两种应力的综合模型的表达形式和适用性进行了分析,并提出上述三个模型的基本使用原则;最后,针对目前核电厂可靠性数据(包括通用数据库和特定核电厂的典型数据)的积累现状,对模型参数的评估方法进行了研究,提出了基于三个不同层次的数据评估方法,简要介绍了每种评估方法的实施步骤和注意事项,并在此基础上,结合中国核电厂可靠性数据的实际情况,提出了中国核电厂备用设备可靠性模型和参数评估方法的使用建议,认为在目前情况下,中国核电厂应该尽可能利用已经积累的电厂典型数据以反映中国电厂的实际情况。

Because a standby equipment is affected by the demand stress and the standby stress simultaneously, its reliability model can take various shapes. This paper first discusses two important models--the standby failure model and the demand failure model. The differences of their assessment of reliability and risk are analyzed to show the characteristics of these two models. Then, an expression considering both the standby stress and the demand stress is proposed, together with its applications, and it is discussed in three aspects. Three evaluating methods for the model parameters are related to the fact that the reliability data include both generic data and special data, The integrated model and the evaluating methods of its parameters are used in evaluating domestic nuclear power plants, where the specific data must be used as much as possible, in order to reflect the realistic states of plants.