Reliability Evaluation of Complex Nuclear Energy Redundancy Systems with Atypical Time-Distribution Events

Abstract

In complex nuclear energy redundancy systems, there are many failure events that do not follow specific time distribution. For these atypical time-distribution events, traditional dynamic fault tree (DFT) methods cannot be applied directly, which has posed great challenges to reliability modeling and evaluating. In this contribution, we summarize atypical time-distribution events in nuclear energy redundancy systems and propose new modeling and evaluating methods based on DFT. To demonstrate the reasonability of the proposed methods, two case studies about make-up water pumps and emergency diesel generators are analyzed in comparison with traditional DFT. The results indicate that the proposed methods can effectively model and analyze the reliability of redundant systems with atypical time-distribution events. The proposed methods can provide useful information for optimization design of nuclear energy redundancy systems and has potential to improve the economy of nuclear power plants by relaxing overestimated unreliability.

Keywords:

• Sequential failure behaviors
• nuclear energy redundancy systems
• dynamic fault trees
• atypical time-distribution events

Acknowledgments

This work is supported by the National Natural Science Foundation of China (71901203) and the National Key R&D Program of China (2018YFB1900301). Also, the authors sincerely thank the editor and anonymous reviewers for their insightful comments that helped us improve the quality of the paper.

Disclosure Statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work is supported by the National Natural Science Foundation of China (71901203), and the National Key R&D Program of China (2018YFB1900301).