The cooling tower at Plant Vogtle’s Unit 3 stands in the background.

ATLANTA – The first of two new nuclear reactors being built at Georgia Power’s Plant Vogtle likely won’t go into service this November as planned, the Atlanta-based utility announced Friday.

The project could be delayed by one month or more at a cost of about $25 million for each month, Georgia Power disclosed in a filing with the U.S. Securities and Exchange Commission.

The nuclear expansion at the plant south of Augusta was originally expected to cost $14 billion when the Georgia Public Service Commission (PSC) approved the project in 2009. The price tag has nearly doubled during the intervening years resulting primarily from the bankruptcy of Westinghouse Electric, the original prime contractor.

Georgia Power attributed the delay to “additional construction remediation work” necessary before the reactor undergoes testing and fuel loading. Originally set to occur this month, the testing has been postponed until April.

“While [Georgia Power affiliate] Southern Nuclear continues to target a November 2021 in-service date for Unit 3, the schedule is challenged and … a delay is likely,” according to the SEC filing.

Kurt Ebersbach, senior attorney for the Atlanta-based Southern Environmental Law Center (SELC), said he wasn’t surprised by Friday’s announcement, considering the start date for testing has been postponed several times since last August.

He predicted the delay likely will stretch at least three months because of the time it takes to test new reactors and conduct fuel loading.

“Georgia Power customers have been paying for this project for over a decade now and were supposed to begin receiving power from it five years ago,” Ebersbach said. “These new delays mean Georgia Power shareholders will continue profiting handsomely while customers get nothing in return.”

The SELC and other opponents of the Plant Vogtle expansion have long argued Georgia Power should pursue renewable energy more aggressively and stop investing in nuclear power.

Both Georgia Power executives and members of the PSC have countered that Georgia must be able to rely on a diverse range of power-generating options to keep electric rates affordable.

Construction of Unit 3, the first nuclear reactor added to Plant Vogtle since the first two reactors went into service in 1987, is now 98% complete. The nuclear fuel assemblies for the reactor arrived on site in December.

Under the current timetable, the fourth reactor is scheduled to go into service in November of next year.