Risk Assessment of Relay Failure in Emergency Diesel Generator of Nuclear Power Plant

As a stable and efficient clean energy, nuclear energy is the main alternative energy for the country to achieve a carbon peak. With the development of nuclear power technology and the maturity of nuclear power plant operation system, more and more nuclear power plants are under construction. At the same time, nuclear safety has been paid more and more attention. For the nuclear industry, nuclear safety is more important than Taishan. From the feedback of the Fukushima nuclear accident, it can be seen that the most important thing for the nuclear power plant is the emergency power supply. As the most important power supply of nuclear power plants, the reliability of emergency diesel generators is directly related to the safety of nuclear power plant. The relay fault in the emergency diesel generator was found in the maintenance of a nuclear power plant in China, which led to a decrease in equipment reliability. Each emergency diesel generator contains about 900 relays of this type, and these relays are located in different positions. Different relay faults have different effects on emergency diesel generator sets. Therefore, it is necessary to analyze the sensitivity of the emergency diesel generator and evaluate the impact of the relay failure on the emergency diesel generator. Through quantitative calculation, this paper analyzes the core risk caused by the relay fault and provides a theoretical basis for making a maintenance plan for a nuclear power plant.