On March 11, 2011, a magnitude 9 earthquake occurred in Japan. The next day, Unit 1 of Japan's Fukushima Daiichi Nuclear Power Plant exploded due to an earthquake. The cooling system of Unit 3 of the nuclear power plant also failed, and an explosion occurred at 11 a.m. on the 14th. At about 6 o'clock today (15th), an explosion occurred in Unit 2 of the nuclear power plant. In addition, two of the three cooling diesel generator sets of the No. 2 reactor of the Ibaraki Tokai Nuclear Power Plant located 120 kilometers north of Tokyo also failed. The nuclear power plant may face serious problems similar to the Fukushima Nuclear Power Plant.

The explosion at the Japanese nuclear power plant should draw great attention from all domestic nuclear power plants. When talking about the cooling system of a nuclear power plant, we need to first briefly explain the "nuclear power plant reactor hydraulic test pump power supply system". The nuclear reactor hydrostatic test pump power supply system is the backup power supply for a million-kilowatt nuclear power plant. Under normal operation of the nuclear power plant, the system is in a standby state; when the nuclear power plant loses all in-plant and off-site power supplies, the system provides emergency power for the reactor hydrostatic test pump to ensure the integrity of the reactor coolant system and provide power to the control instruments required for unit operation. As an independent backup power supply, the hydrostatic test pump power supply system is a barrier to the safety of nuclear power plants.

In China, in the past, the hydraulic test pump power system used mostly small steam turbine generator sets produced by foreign companies. However, these foreign companies usually get stuck in key technologies due to domestic nuclear technology export restrictions or other reasons, or directly stop supplying new nuclear power projects.

China Guangdong Nuclear Power Group decided to break this situation with the Ling'ao Nuclear Power Plant Phase II project. Their engineering and technical personnel are based on independent innovation and break through foreign technological blockades. Based on a comprehensive technical analysis and drawing on the latest design concepts of foreign four-circuit nuclear power units and third-generation nuclear power technology, a localization plan was proposed to replace the steam turbine generator unit with a small diesel generator unit. This solution can be separated from the main steam system, reducing interfaces, and the system design is simpler and more reliable.

In this project, China Guangdong Nuclear Power Group conducted a full investigation of domestic diesel generator set manufacturing enterprises, conducted extensive technical exchanges and demonstrations with relevant manufacturers and design institutes, carefully analyzed the feasibility of localization of system design and manufacturing, and assisted the enterprise to familiarize itself with the functions and requirements of the nuclear power plant's hydrostatic test pump power supply system. Finally, through the bidding, there have been many years of research and development of diesel generator sets and their supporting products.

Nuclear safety-level generator sets have very high requirements in terms of design technology: reaching the safety level of mechanical equipment, passing level 8 seismic tests, 100 consecutive successful starts, computer intelligent monitoring and historical recording, optimized fault signal judgment, etc.