An Area IF-Defuzzification Technique and Intuitionistic Fuzzy Reliability Assessment of Nuclear Basic Events of Fault Tree Analysis

摘要

In many areas such as nuclear engineering, quantitative historical failure data are unavailable or inadequate to access the nuclear event reliability data and only qualitative data such as expert opinions can be utilized. In this paper, qualitative data are mathematically represented by membership and non-membership functions of intuitionistic fuzzy numbers (IFNs) instead of fuzzy numbers. The objective of this research is to develop a novel area IF-defuzziflcation technique for IFNs and to assess nuclear event reliability data from their corresponding failure possibilities described in linguistic terms and expressed mathematically in term of IFNs. The proposed area IF-defuzzification technique is justified by defining five intuitionistic fuzzy rules. The reliability data computed from the proposed technique is then compared with the actual event reliability data collected from the operational experiences of the reactor protection system in Babcock & Wilcox pressurized water reactor between 1984 and 1998.