Study On Reliability Modeling And Analysis Of Phased Mission Typical Nuclear Power Equipment Using Goal Oriented Methodology

The phased mission system is a kind of ubiquitous especial complex system in nuclear industry.The mission reliability of such system is not only a primary index to measure the ability that whether it can complete the prescribed task safely and favorably in the specified mission section or not,but also a vital indicator used in probability security assessment of nuclear power system.Therefore,the study on appropriate reliability modeling and analysis methods to obtain accurate system mission reliability has become the focus of reliability analysis of the phased mission nuclear power equipment.Goal Oriented(GO)methodology,as a success-oriented reliability modeling and analysis method,has unique advantages in complex system reliability modeling and analysis.It provides new idea for solving the problem in reliability modeling and analysis of the phased mission system.In this paper,the advantages and disadvantages of various reliability modeling and analysis methods commonly used in phased mission system are analysized by investigating the research status of those methods,as well as the advantages and applicability of GO methodology in phased mission system.Then,combining the existing GO theory with the reliability analysis theory of phased mission system,a phase dependency processing method based on the rule of phase algebra for the probability operation of GO method is proposed.Furthermore,a new and more rigorous definition of shared signal and its decision rules are given,and an improved accurate algorithm in processing shared signals in the GO model has been provided.In addition,the reliability modeling and analysis method of phased mission system based on GO methodology is established,and the corresponding analysis process and rules are made.On this basis,the proposed method is used in the reliability modeling and analysis of hoisting mechanism in nuclear island,as a typical phased mission system.Then the mission reliability of each phased mission,as well as the whole system mission and its minimum cut set,are acquired by solving the GO model.Subsequently,the correctness and applicability of the proposed method is verified separately by comparing the corresponding results based GO methodology with the qualitative analysis results based on FTA and the quantitative simulation results based on Monte Carlo.Finally,a software used in reliability modeling and analysis of nuclear power equipment based on GO methodology is developed by combining the GO theory in complex system reliability analysis with the requirement of nuclear power system reliability analysis.It can help engineers to improve effectively the reliability modeling and analysis efficiency on nuclear power equipment.