MONROEVILLE — Westinghouse Electric has signed a deal to design and build two nuclear reactors at a Georgia power plant, marking the first time in nearly 30 years a company has signed a deal for a nuclear power facility in the United States.

Westinghouse, which is based in Monroeville, and The Shaw Group, which owns 20 percent of Westinghouse, have agreed to build two 1,100-megawatt nuclear reactors at Plant Vogtle in east Georgia, which Georgia Power Co. co-owns with other utilities. The plant is already home to two reactors.

Westinghouse Electric is building its new international headquarters in Cranberry Township with an expected 3,000 jobs coming to Butler County in the next two years.

The company already has moved 400 employees to Cranberry as part of this change.

Georgia Power plans to submit the engineering agreement to the state Public Service Commission by May 1. The proposed reactors also would require approval by the Nuclear Regulatory Commission.

No new nuclear power plant projects have been licensed since the partial meltdown in 1979 at Three Mile Island near Harrisburg. The cost of the reactors wasn't disclosed, but estimates run up to $6 billion.

Combined with the existing reactors, the units would make Plant Vogtle, along the Savannah River southeast of Augusta, one of the nation's largest generators of nuclear power.

"If the PSC approves, we are going forward with the new units," Georgia Power spokeswoman Carol Boatright said.

Last month Southern Nuclear Operating Co., a sister company of Georgia Power that runs the plant, filed an application with the NRC for a combined construction and operating license for the new units. Approval is expected next year, and the reactors could begin operation in 2016-2017.

At least three other companies have filed applications with the NRC: Richmond, Va.-based Dominion Resources to add a reactor at its North Anna Power Station in Virginia; the Tennessee Valley Authority, for new reactors at the Bellefonte station near Scottsboro, Ala.; and NRG Energy to build and operate new reactors at its Bay City, Texas, power plant site.

The NRC has predicted it will get new construction and operating license applications for as many as 29 reactors at 20 sites nationwide.