Research And Development Of Graphic Diagnosis System For Nuclear Power Plant Based On Fault Tree

As a kind of efficient and clear energy resource, nuclear power’s share in energy structure will become higher, and nuclear power plant is more strict with the requirement for safety. During the research, it has been found that nuclear accident caused mainly by personal faulty operation. Therefore, on the basis of the digital I&C system and real time data monitoring system of NPP, it is significant to develop a set of diagnostic system, which can assist operators with making right decisions to accidents.Fault Tree Analysisis is a useful tool to analyze the reliability of complex systems, it can provide analysis basis for development of diagnostic system. Digital I&C system is not only a critical part to ensure the safe and reliable operation of nuclear power plant but also indispensability part for the reliable analysis of nuclear power plant. This paper takes Digital I&C system of CPR1000 as research object and carries on fault analysis and establishes mathematical model for KCS system. In order to reduce the workload of modeling analysis, based on the mathematical model algorithm, this paper develops Fault Modeling Analysis Software via secondary development of Visio and ActiveX control of VC++.This paper proposes the graphic design concept, which can make the operators have a more intuitive understanding of the source and path of the fault through the graphical diagnostic system. The diagnosis system is mainly divided into three parts, the interactive interface, the background program and the knowledge base. Interactive interface completes the picture of the drawing via HTML5+CSS3 technology; the background background program can analyse and reason the data through compiling the algorithm using JavaScript language; knowledge base uses MySQL database, the communication between database and background program relys on PHP framework, the knowledge base adopts production rules to express the information and it realizes the collation and preparation of knowledge by the fault tree analysis results,alarm manual and other information. The fault tree is embedded in the diagnosis system in the form of a list, and KNS system of the nuclear power plant is connected to the system in real time.When an abnormal signal happens, the corresponding fault tree graph sticky displays, and fault path and suggestions decisions information are shown to complete graphic diagnosis for real-time data signal.In order to enhance the dynamic performance of graphic diagnosis system, this paper combines with dynamic fault tree concept to develop static fault tree diagnosis system and expand its functions, and the mathematical model of dynamic fault tree is also established, so that diagnosis images can be carried out in accordance with the real-time fault dynamic, and it can calculate the probability of occurrence of different fault conditions to let the operators have more efficiency on the response of fault occurrence. In this paper, the technical methods of the graphical diagnosis system has a strong expansibility, which can be used for fault diagnosis of the digital I&C system of the whole nuclear power plant, and reduce the probability of human misoperation.