Reports of cost overruns and scheduling delays loom over Georgia Power's Plant Vogtle expansion project.

But as far as Georgia utility regulators were concerned Tuesday, Georgia Power's $6.1 billion portion of Vogtle is tracking about $28 million under budget.

The Georgia Public Service Commission unanimously signed off on the utility's latest construction and schedule report, which covers July 1 through Dec. 31, 2011. The PSC reviews the project's costs every six months as part of a way to catch any potential increases early. Such cost overruns could wind up on customer bills, if approved.

Although questions have been raised about cost overruns and scheduling delays, "the company has not requested any changes to the project schedule" or to the budget, said Dennis Sewell, a PSC staff member, during Tuesday's meeting.

At $14 billion total, Vogtle is one of Georgia's largest and most expensive economic development projects, adding 5,000 temporary construction jobs and 800 permanent ones to the Waynesboro area. The company touts economic benefits such as tax breaks and low interest rates and commodity costs. These lower costs will help customers save $2.2 billion total on their electric bills over the next several decades, the company said.

An independent utility watchdog has warned of scheduling delays at Vogtle, however. The delays have made the project's capital and financing costs go up, he said.

In addition, Georgia Power is disputing its responsibility for a $425 million cost overrun stemming from delays in getting key license approvals from federal regulators. The project's main vendors, Westinghouse and The Shaw Group, say Georgia Power is responsible for that amount. Separately the vendors have sued the utility and the project's co-owners for additional expenses that came from backfilling two excavation sites at Vogtle.

The continuing dispute over who will pay for those escalating costs may force the reactors to start producing power later than their scheduled 2016 and 2017 dates, the utility's parent, Southern Co., said in a recent document.

Georgia Power and a group of municipal and cooperative electricity utilities are adding two reactors at Vogtle. The reactors are the first in the United States to win permits in 30 years.