Updated at 5:22 p.m. EST.

The chairman of the Nuclear Regulatory Commission defended his decision today to oppose Southern Co.'s bid for a license to build the nation's first new nuclear plant in more than three decades.

NRC Chairman Gregory Jaczko voted against NRC granting Southern Co. and other utilities a license to build two new reactors in Georgia, but his fellow commissioners -- two Republicans and two Democrats -- approved the license and trumped his objections.

The consortium of utilities led by Southern Co. could receive a license as early as tomorrow to begin building two $14 billion reactors at the Vogtle nuclear power plant complex, about 170 miles east of Atlanta, NRC said. Unit 3 is expected to be operational by 2016 and Unit 4 by 2017.

The commission released an order today outlining its approval for the reactors.

But Jaczko said during an interview today that NRC has no way of knowing if Southern will make safety upgrades following the nuclear plant disaster in Japan last year.

"It's like buying a car with a recall notice," Jaczko said. "You'd want to get those issues fixed before you drive the car off the lot."

Southern should have been required to agree to meet any safety changes the agency crafts in the coming months, Jaczko said. NRC hopes to finalize a set of safety rules stemming from the crisis last year at Japan's Fukushima Daiichi nuclear plant. Three reactors at the site experienced core meltdown after the facility was struck by a magnitude-9 earthquake and tsunami that wiped out power to the plant.

A number of the new provisions could apply to the Vogtle plant but will now be difficult to impose because regulators are required to consider cost and link any changes to language in a plant operator's license, Jaczko said.

The chairman said he would have supported the license if that language had been included.

"Our experience has shown that even when we identify serious safety concerns, licensee resolution of those concerns and implementation of necessary changes can be subject to lengthy delays," Jaczko wrote in a decision the commission released today.

NRC officials said any new provisions that come from the Fukushima review will apply to new and existing reactors, and will apply to different types of reactors. The NRC has the legal authority to shut a plant down if the operator is not in compliance with federal regulations, they said.

Thomas Fanning, Southern Co.'s chairman and president, told reporters on a conference call today that the company will make any safety changes the agency requires related to the Fukushima disaster. "Anything that we learn from Fukushima, I assure you, we will bring to bear ... here at our operations," he said.

Fanning also said the company did not rush the plant's license approval and that the seven-year process has been "very deliberate, thorough, thoughtful."

The Vogtle plant is also in a different situation than the Japanese plant, he said, because the reactors will sit 130 miles from the coastline, 220 feet above sea level. They will not be located in a seismically active area, and the plant will use passive technology to cool the reactors during an emergency.

"There will be issues that apply to the United States nuclear fleet, but they apply much more closely to the current fleet of nuclear plants, not this newest generation of nuclear technology," he said.

Jaczko would not comment on whether his concerns about the post-Fukushima review would apply to a number of reactors that NRC could license in the coming weeks.

Sources watching the agency say the commission may address a license application for the V.C. Summer project in South Carolina this month.

In the meantime, some lawmakers are already calling for the commission to approve more reactors.

Sen. Lamar Alexander of Tennessee, the ranking Republican on the Senate Energy and Water Development Appropriations Subcommittee, said NRC should quickly approve 14 other reactors that use the same model as the Vogtle plant.

"Our country will need 100 new reactors to provide enough reliable, clean electricity to power our homes, businesses, computers and vehicles," Alexander said in a statement.

Click here to read NRC's order.