Unit 1 of the Sanmen nuclear power plant has been connected to the grid, becoming the world's first AP1000 to achieve grid connection and power generation. 

Sanmen 1 was connected to the grid for the first time at 4.48pm on 30 June, "The technical indicators met the design requirements and the reactor status was well controlled, indicating the unit's construction formally entered the grid-connected commissioning phase for subsequent operation at various power levels," China's National Nuclear Safety Administration (NNSA) said. "The milestone has laid a solid foundation for transient testing and scheduled commercial operation."

Hot testing of Sanmen 1 was completed in June last year. The loading of fuel assemblies into its core began on 25 April following the issuance of a permit by the NNSA. The unit achieved first criticality - a sustained chain reaction - on 21 June. On 27 June, nuclear-generated steam was used for the first time to successfully rotate the turbine at rated speed.

The unit will now undergo gradual power ascension testing until all testing is safely and successfully completed at 100% power. Sanmen 1 is scheduled to enter commercial operation by the end of this year.