Southern targets Dec start for new Georgia Vogtle 3 nuclear reactor

(Adds latest capital cost from Southern in last paragraph)

April 29 (Reuters) - U.S. energy company Southern Co said Thursday it was targeting a December in service date for the third reactor at its Vogtle nuclear power plant in Georgia.

That is about a month behind the unit’s regulatory-approved November in-service date but is in line with the possible delay Southern announced last month.

Southern, which released the Vogtle update as part of its quarterly earnings report, said the unit started “hot functional testing” on April 25. That is one of the last major tests prior to loading fuel into the plant, which Southern expects to occur in the third quarter.

Southern also said it remains on track to put the fourth reactor at Vogtle into service between August-November 2022, which is prior to/in line with that unit’s regulatory-approved November 2022 in-service date.

The two units at Vogtle are the only big nuclear reactors under construction in the United States.

When Georgia utility regulators approved the Vogtle expansion in 2009, the two 1,117-megawatt Westinghouse AP1000 reactors were expected to cost about $14 billion and enter service in 2016 and 2017.

But some analysts estimate costs have ballooned to more than $25 billion due to delays related to the nuclear accident at Japan’s Fukushima plant in 2011 and the 2017 bankruptcy of Westinghouse, the project’s former lead contractor.

Delays and cost overruns in building reactors could make it difficult for new nuclear facilities to play much of a role in the Biden administration’s plan to get all of the nation’s power from non-carbon-emitting sources like nuclear and renewables by 2035.

Southern estimated the capital cost for its 47.5% share of the new Vogtle reactors would be about $8.8 billion. Southern has already spent about $7.6 billion as of March 31.

In addition, the company has estimated its construction financing costs at around $3.0 billion.

Reporting by Scott DiSavino; Editing by Bernadette Baum, Will Dunham and Nick Zieminski