Cold testing at unit 3 of China’s Sanmen NPP in Zhejiang province, has been successfully completed, according to China National Nuclear Corporation (CNNC). Cold testing is a key milestone in the nuclear power commissioning process and lays a solid foundation for subsequent unit hot tests, charging start-up and other work.
The construction of two new units at each of the Sanmen (3&4), Haiyang (3&4) and Lufeng (5&6) NPPs was approved by China’s State Council in April 2021. Two Westinghouse AP1000 units built as Phase I of the Sanmen plant (1&2) started operation in 2018. Two CAP1000 reactors are being constructed as Phase II of the plant (units 3&4).
The CAP1000 is China’s version of the Westinghouse AP1000. It uses modular construction techniques, enabling large structural modules to be built at factories and then installed at the site. This reduces construction time and improves quality control. First concrete was poured for the nuclear island of Sanmen 3 in June 2022 and first concrete for unit 4 in March 2023. The units are expected to be connected to the grid in 2027 and 2028.
Once units 3&4 are completed and put into operation, Sanmen Nuclear Power’s annual power generation will exceed 40 TWh, equivalent to reducing carbon dioxide emissions by 30m tonnes a year.
