The welding of the main pipe on Fuqing Unit 6, part of the HPR1000 (Hualong 1) reactor currently being built in China’s Fujian province, is completed on June 24. [Photo/CNNC]

The welding of the main pipe on Fuqing Unit 6, part of the HPR1000 (Hualong 1) reactor currently being built in China’s Fujian province, was completed on June 24, according to a CNNC announcement.

The welding work started on January 14 and took 162 days to complete, a time span shorter than any one of the other five Fuqing units.

The main pipe of a nuclear island is connected with the reactor pressure vessel, steam generator and the main coolant pump; it is an important part of the pressure boundary of the reactor coolant system. It consists of three circuits, with each of the circuits comprising of a hot section, cold section and transition section. 

As a grade-A piece of safety equipment essential for nuclear safety, the main pipe of a nuclear island can withstand the high temperature and high pressure of the reactor coolant for a long period of time while in operation, making it the main artery of a nuclear power plant.

CNNC staff work on the welding of the main pipe on Fuqing Unit 6, part of the HPR1000 (Hualong 1) reactor currently being built in China’s Fujian province. [Photo/CNNC]