The unit 3 reactor at Plant Vogtle near Waynesboro, Georgia, has started commercial operation, primary owner Georgia Power said on Monday. This follows preliminary tests in March.

The reactor, an Westinghouse AP1000, is generating approximately 1,110 megawatts of energy, which can power an estimated 500,000 homes and businesses, Georgia Power said.

The last time a nuclear reactor started delivering energy to the power grid was in October 2016, when the Tennessee Valley Authority began commercial operation of its Watts Bar Unit 2 near Spring City, Tenn., according to Scott Burnell, a spokesperson for the Nuclear Regulatory Commission. Prior to that, there hadn't been a new nuclear reactor turned on since Watts Bar 1 in May 1996.