The AP1000 reactor is now generating electricity and was connected to the grid for the first time on 1 March, Georgia Power has announced.

Vogtle 4 joins Vogtle 3 in supplying electricity to the grid (Image: Southern Company)

The unit, at Waynesboro, Georgia, reached initial criticality on 14 February. Synchronisation and connection to the grid is part of the ongoing start-up testing process, which will now see the plant's operators continue to raise reactor power while performing tests at various power levels, ultimately raising power to 100%. Once all start-up testing is successfully completed and the unit is available for reliable dispatch, Vogtle Unit 4 will enter commercial operation. The company currently projects an in-service date during the second quarter of this year.

Vogtle 4 is one of two Westinghouse AP1000s being built at the Vogtle expansion project: the site is already home to two operating pressurised water reactors. Unit 3 reached first criticality in March 2023, and began commercial operation in July.

The last reactor to start up in the USA before Vogtle 3 was Watts Bar unit 2, in 2016. Construction of that reactor began in 1973 and was suspended in 1985 before work resumed in 2007.

The new Vogtle units are co-owned by Georgia Power, Oglethorpe Power, MEAG Power and Dalton Utilities, and operated by Southern Nuclear. Georgia Power is a subsidiary of Southern Company.