Nuclear-Class Butterly Valve' Reliability And Security Analysis Based On Fuzzy Theory

Nuclear is the clean energy and establishing the construction of nuclear is the important and critical strategy in our country. Nuclear facilities is the premise and basis of the construction of nuclear and nuclear-class valve takes a large proportion of the nuclear equipments. With the increasement of nuclear-class valve demand, it is necessary to improve and enhance the reliability of nuclear-class valve. However, because of the particularity of nuclear equipment, it is found that the traditional analytical methods of reliability has its own shortcomings when it is used. The paper makes up for the deficiencies of traditional reliability analysis way on the basis of fuzzy theory to a certain degree.This paper gives a brief introduction about the concept and research situation of fuzzy theory and the reliability, engineering applications features and development of the nuclear-class valve at home and abroad and then introducs the analysis steps and applied process of FTA, FMECA and fuzzy comprehensive evaluation method. Taking nuclear-class butterfly valve as example, the paper illustrates the features and methods of FTA technology used in nuclear-class valve research and analyzes nuclear-class butterfly valve's failure mode, causes and influence.Besides, the paper provides some improved measures and methods for it and prepares for the latter security assessment. For nuclear vavle's security assessment, the paper gives the FMECA analysis for nuclear-class butterfly valve and works out the FMECA report. On such basis, the paper analyzes the safety of it by making use of the fuzzy comprehensive evaluation method and gets security rating. Lastly, the paper concludes the cycle process diagram of reliability and security and emphasizes that such cycle is valuable to enhance and improve the products' quality and reliability.