Research on aging-related degradation of control rod drive system based on dynamic object-oriented Bayesian network and hidden Markov model

Autor: Kang Zhu, Xinwen Zhao, Liming Zhang, Hang Yu
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Nuclear Engineering and Technology, Vol 54, Iss 11, Pp 4111-4124 (2022)
Druh dokumentu: article
ISSN: 1738-5733
DOI: 10.1016/j.net.2022.06.020
Popis: The control rod drive system is critical to the reactor's reliable operation. The performance of its control system and mechanical system will gradually deteriorate because of operational and environmental stresses, thus increasing the reactor's operational risk. Currently there are few researches on the aging-related degradation of the entire control rod drive system. Because it is difficult to quantify the effect of various environmental stresses and establish an accurate physical model when multiple mechanisms superimposed in the degradation process. Therefore, this paper investigates the aging-related degradation of a control rod drive system by integrating Dynamic Object-Oriented Bayesian Network and Hidden Markov Model. Uncertainties in the degradation of the control system and mechanical system are addressed by using fuzzy theory and the Hidden Markov Model respectively. A system which consists of eight control rod drive mechanisms divided into two groups is used to demonstrate the method. The aging-related degradation of the control rod drive system is analyzed by the Bayesian inference algorithm based on the accelerated life test data, and the impact of different operating schemes on the system performance is also investigated. Meanwhile, the components or units that have major impact on the system's performance are identified at different operational phases. Finally, several essential safety measures are suggested to mitigate the risk caused by the system degradation.
Databáze: Directory of Open Access Journals