A Details Study on Evaluating Emergency Diesel Generator Reliability in Nuclear Power Plants

This study presents a reliability analysis of the emergency diesel generator (EDG) system in nuclear power plants (NPPs) using fault tree analysis (FTA) in combination with survival signature method. Analysis assesses the robustness of the EDG system, which plays a critical role in sustaining essential functions during power outages. Given this importance, the system must meet high standards in design, operation, and maintenance to ensure quick start-up and reliable operation. The analysis begins by decomposing the EDG system into subsystems and components, followed by the construction of a fault tree that maps potential failure scenarios and their causal relationships. The study is based on specific assumptions, including non-repairable components, independent failure events, and defined failure time distributions. The core technical content of the chapter centers on the calculation of the survival signature. It systematically outlines the process, including the formation of component state vectors, the use of Boolean algebra to determine system functionality, and the integration of these elements to derive the survival signature. To demonstrate the practical implementation of this method, the chapter concludes with the development of a MATLAB function that calculates system reliability. This function embodies the theoretical framework of the survival signature approach and validates its effectiveness through numerical results.