ROCKVILLE, Md. -- A federal panel weighed the merits of Georgia Power’s proposed new nuclear reactors Tuesday, a critical and nationally watched step toward the expansion of Plant Vogtle.

The Nuclear Regulatory Commission hearing, which lasted all of Tuesday and is scheduled to conclude Wednesday, is the first of its kind under a more streamlined process to approve new reactors. It is a crucial hurdle in allowing the first new reactors in the United States in more than three decades to be completed near Augusta in 2016 and 2017.

Chairman Gregory Jaczko opened by calling it “an important and historic day at the NRC.” The five-person panel heard testimony from Southern Nuclear -- Georgia Power’s sister company, which oversees Plant Vogtle -- and NRC staff who have given preliminary approval to the project.

The NRC is scrutinizing the Plant Vogtle plans to see if they meet environmental and safety standards. The commission is in charge of issuing a construction license for the expansion.

The Obama administration has pushed nuclear power as an alternative to fossil fuels and has extended a preliminary loan guarantee of about $8 billion for the project, which is slated to be a $14 billion investment in all. But public opinion was stirred up by the meltdown at the Fukushima Daiichi nuclear plant in Japan this year after an earthquake and tsunami.

Robert Schaaf, an NRC staffer who participated in the environmental review, told the panel “the current plants and licensing are not expected to be affected" by the Fukushima disaster, based on an initial probe.

NRC commissioner George Apostolakis pointed to the 13,000 public comments on the plan, an unusually large number. But Michael Johnson, the director of the NRC's office of new reactors, noted the comment period came in the midst of heightened debate over the Fukushima disaster, and many of them were form letters. There were about 60 separate issues raised that the agency will respond to, Johnson said.

The panel is not expected to make its final determination until early next year.

David Matthews, director of new reactor licensing with the NRC, said in an interview that the process is deliberate because of the inherent complexity in nuclear power and the fact the reactors could be producing electricity for the next 60 years.

“This is quite a legacy issue and it deserves the time it takes, even though we’ve had many critics argue that it should be done faster,” Matthews said. “We’re of the view that it needs to be done well and that needs to take as much time as it needs, as opposed to meeting some sort of artificial schedule.”