The second of the two new nuclear units at Plant Vogtle, known as Unit 4, has been cleared by federal regulators to load fuel, Georgia Power announced Friday morning.

The development is the latest in a flurry of activity at the site in Burke County, about 35 miles south of Augusta. On Thursday, a witness for the Georgia Public Service Commission’s (PSC) staff testified that the other new reactor, Unit 3, had successfully completed one of its final required safety tests and could begin providing electricity to customers within days.

The greenlight to load nuclear fuel into Unit 4 comes in the form of a 103(g) letter issued by the Nuclear Regulatory Commission. The letter from the commission sent to Georgia Power means that after reviewing a set of tests and analyses submitted earlier this month by the company, regulators found that the unit met all construction and safety requirements.

In its release, Georgia Power said it was “working diligently” to prepare for fuel load, but did not indicate exactly when all 157 nuclear fuel assemblies would be placed into the reactor.

After the fuel rods are loaded, the company said it would begin a series of start-up tests, which are expected to take several months. Once complete, operators will take the reactor from cold shutdown mode to “initial criticality,” where atoms are split inside the reactor. Then, the unit will be synced with the grid and power will be gradually increased, while another battery of tests are conducted.

Fuel load approval is another key milestone for the Vogtle project, which has been beset by years of delays and billions in cost overruns. Unit 3 is more than seven years behind schedule and its twin, Unit 4, will be at least six years late once completed. Their total combined cost, meanwhile, has swelled to more than $35 billion, more than double Georgia Power’s initial forecast.

Once complete, Georgia Power says the units will be in-service for the next 60 to 80 years. At maximum power, each reactor will produce 1,100 megawatts of electricity, enough to power about 500,000 homes and businesses. At a time of rising temperatures and rapidly worsening climate change impacts, the company has said the units will provide a critical source of clean energy.

While the company has repeatedly blown past deadlines, Georgia Power says it expects Unit 4 will load fuel in the third quarter this year and be complete by the end of the first quarter in 2024.

At a PSC hearing this week, witnesses for the commission’s public interest staff said Georgia Power appears to be applying lessons learned from the rocky construction and start-up of Unit 3, leading to quicker progress on Unit 4.

William Jacobs, one of several independent monitors enlisted by the commission, said Thursday that Unit 4 completed its required “hot functional testing” in 42 days — less than half the time it took for Unit 3. Jacobs added that lengthy backlogs of inspection reports, which delayed Unit 3 by months and added an estimated $500 million to its cost, haven’t been an issue at Unit 4.

It’s not clear exactly how much of Vogtle’s cost overruns will ultimately get passed on to ratepayers, but the process of figuring that out could begin soon.

After fuel is loaded into Unit 4, the PSC will hold a series of “prudency hearings” to determine which Vogtle costs Georgia Power will be allowed to recoup from ratepayers.

While Georgia Power has reserved the right to seek collection of additional costs, the company has indicated it could ask for roughly $7.7 billion to be added into rates. PSC staff experts say that if state regulators approve such a figure, it could raise the average residential customer’s monthly bill by $14.10 per month for the first five years after the units are in service. The monthly increase would drop slightly to $13.20 for the next five years.

For years, Georgia Power’s customers have been paying for the reactors before they provide any electricity.

Thanks to a “nuclear cost recovery” fee that’s been on customers’ monthly bills, the average Georgia Power residential customer will have paid about $926 for Vogtle construction by the time Unit 4 is complete. That means the company will have raked in an estimated $4.2 billion from ratepayers before the units enter commercial operation, double what it would have received if the units had been completed on schedule.


A note of disclosure

This coverage is supported by a partnership with 1Earth Fund, the Kendeda Fund and Journalism Funding Partners. You can learn more and support our climate reporting by donating at https://www.ajc.com/donate/climate/