Unit 3 of the Vogtle Nuclear Plant is back online and operating normally, majority owner Georgia Power Co. said, after plant operators shut down the new reactor July 8 to repair a faulty valve.
A valve issue on one of the three main feedwater pumps at unit 3 caused lower water levels in the steam generators, prompting shutdown of the unit. The plant, including all safety systems, responded as designed, Georgia Power spokesperson John Kraft told S&P Global Commodity Insights on July 17.
Repairs have been completed, and the unit came online July 17 and is sending power to the grid, Kraft added.
The Southern Co. subsidiary recently completed a two-unit expansion of the Vogtle plant that began nearly two decades ago. Unit 3 entered commercial operation in July 2023, and unit 4 entered commercial operation in April 2024.
The two new pressurized water reactors have nameplate capacities of 1,114 MW each, according to S&P Global Market Intelligence data, and will replace some of the coal- and gas-fired power plants Georgia Power intends to retire by 2028.
The new reactors have been "performing exceedingly well" since they entered service, Kraft said.
"Since unit 3 went online July 31 of last year, it has operated at full power more than 98% of the time," Kraft added.
Total cost estimates for the Vogtle additions are difficult to determine, given variables such as financing costs across multiple owners and $3.7 billion provided due to the bankruptcy of Westinghouse Electric Co. LLC, the original builder. Some estimates top $30 billion, and testimony at Georgia Public Service Commission hearings in December 2023 included estimates of $32 billion to $35 billion or higher.
Georgia Power owns the largest share of both the original two reactors at Vogtle, as well as the new ones, at 45.7%. Other owners are Oglethorpe Power Corp., which supplies power to Georgia electric cooperatives, at about 30%; the Municipal Electric Authority of Georgia, which supplies power to 49 public power entities in Georgia, at 22.7%; and the city of Dalton, Ga., at 1.6%. Southern Nuclear Operating Co. Inc. operates the units on behalf of the co-owners.
Rising US power demand and Vogtle's completion are raising the profile of nuclear as a carbon-free answer to US energy needs, and many utilities are weighing capacity increases at existing plants, restarts or repowerings.
