Facility will eventually consist of six Hualong One units
Unit 1 of the Sanao nuclear power station in the eastern Chinese province of Zhejiang reached first criticality on 14 February, according to local sources.
Sanao-1 is a 1,117-MW domestic Hualong One, or HPR1000, pressurised water reactor (PWR) unit.
First criticality at a PWR is the moment when the reactor core achieves a self-sustaining nuclear chain reaction for the first time.
Construction of Sanao-1 began in December 2020. The unit completed hot functional testing in June 2025.
Fuel was loaded into the reactor core in late December 2025 after the unit received an operating licence earlier that month.
The Sanao nuclear power station will eventually consist of six Hualong One units, with Sanao-1 now under commissioning and another two, Sanao-2 and -3, being under construction.
The Hualong One is an indigenous pressurised water reactor unit that incorporates elements of China National Nuclear Corporation’s ACP1000 and China General Nuclear’s ACPR1000+ reactor designs.
China is moving forward with its indigenous reactor technology. About a half of the county’s 36 reactor units under construction are of the Hualong One design.
