First Backup Emergency Diesel Generator of Hualong One Officially Available at Sanao Nuclear Power Unit 2

On October 2, the first backup emergency diesel generator (9LHW) of "Hualong One" completed the replacement grid connection test at Sanao Nuclear Power Unit 2 and was officially put into service. The equipment can replace any one of the original 12 emergency diesel generators (EDGs) in Phase I and Phase II projects, significantly improving the redundancy, reliability, and maintenance flexibility of the plant's emergency power supply.

Sanao Nuclear Power Phase I and Phase II each have 3 emergency busbars, with one EDG configured for each busbar. However, due to the absence of cross-power supply for loads, the preventive maintenance windows of the original units were concentrated, affecting the overhaul schedule. Since 2021, Cangnan Nuclear Power has promoted the project of adding backup diesel generators, improving from the design source, building a new backup emergency diesel generator building (BDD), and constructing corridors and cables connected to each unit, so as to solve the problems of availability and operation and maintenance economy.

During the commissioning period, Cangnan Nuclear Power and the Cangnan Project Department of China Nuclear Power Engineering Co., Ltd. formed a joint task force to overcome problems such as lube oil filter jamming and oil return pipe vibration, and successfully completed the 24-hour full-load operation and replacement test. This project filled the gap in China General Nuclear Power Group's independent commissioning technology for the new backup diesel generator of "Hualong One," transformed major design changes into a reliable safety barrier, and laid a solid foundation for the safe commissioning of the unit.