Maintenance And Life Cycle Management For Nuclear Plant Components Based On Reliability

Reliability centered maintenance (RCM) and life cycle management (LCM) is being paid more and more attention in the management of nuclear power plants. According to the demand of the RCM and LCM of repairable equipments, this thesis presents a suitable model for the management of maintenance and life cycle determination of nuclear power plant based on the theory of traditional RCM and the theory of stochastic process and fuzzy.Considering the characteristic of the failure data of repairable equipments in nuclear power plants, traditional methods of failure data processing are summarized and their limitations are pointed. The paper presents a method of failure data processing, using the formulas of Weibull process, which is a special form of non-homogeneous Poisson process, to simulate the process of equipment's failures. Detail utilization of the method is also included in the thesis.The influence of repair to the failure rate of equipment in nuclear power plant should be considered when the traditional RCM is applied. This thesis discusses the feasibility of using an age reduction factor to measure the repair degree and the method to calculate the factor. When the failure data is not enough to calculate the factor, an approximately fitting function with Weibull process is proposed to improve the model's capability.The LCM determines those on-service or new facilities'life cycle by the calculation of the empirical lifetime of used equipments. The traditional method fits the distribution of the lifetime of used equipments to get the empirical lifetime. Based on the Weibull process, the thesis presents a new method of life cycle determination with failure rate index. We can obtain the failure rate index of life management by fitting the distribution of failure rates at the moment of the replacement or using the theory of fuzzy and the theory of reliability allocation. This failure rate index is used to calculate the empirical lifetime.At the end of this thesis, several cases are presented to verify the new methods' capability, including failure data processing of repairable equipments, LCM model based on Weibull process and LCM model based on failure rate index.