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.