The evolving disaster at Japan's Fukushima Daiichi nuclear plant had Southern Co. executives working through the weekend to control political damage to nuclear expansion ambitions in the United States.

Southern is at the head of that push nationally.

Its two-reactor project at the Vogtle nuclear plant near Augusta is one of three survivors of what was billed as a national nuclear renaissance a few years ago. If they're completed by 2017, the reactors would be the first ones started and finished in the U.S. since the Three Mile Island disaster soured the public on nuclear power in the 1979.

The Japan disaster threatens to blacken the industry's eye again, with some calling for a moratorium or slowdown on new reactors.

Sen. Joe Lieberman, I-Conn., a nuclear power backer, told CBS on Sunday that the country should "quietly, quickly put the brakes on" and "see what more, if anything, we can demand of the new power plants that are coming on line."

Nuclear opponents called for the expansion to stop: "It's another example of what we have been saying," said Stephen Smith, executive director of the Southern Alliance for Clean Energy. "Nuclear power is not inherently unsafe. But it is inherently unforgiving."

Internationally, Switzerland announced a freeze on any new plants or replacement work. Germany will delay by three months a decision to refurbish the nation's nuclear facilities.

The stock market also piled on, pounding nuclear-related stocks, including Southern's nuclear construction partner, the Shaw Group. Its stock closed down 9.2 percent on Monday after a sharp sell-off during morning trading.

The industry has circled the wagons. The Nuclear Energy Institute, a trade association, held a phone conference with analysts to argue against an overreaction and explain why new U.S plants will have both more scrutiny and a lower risk of natural disaster than those in Japan.

The NEI said the industry "will incorporate lessons learned from the events in Japan into the ongoing process of designing, licensing and building new nuclear power plants."

Southern spokesman Todd Terrell said company staff spent the weekend drafting a response, while monitoring the deteriorating situation in Japan. "I was here 18 hours [Sunday]," he said.

By Monday, the company had a series of detailed talking points on its website, including statements in support of new nuclear development from Shaw, reactor designer Westinghouse and the Obama administration. The company also met with political officials, including utility regulators responsible for overseeing the Vogtle project.

The company said Vogtle site isn't earthquake prone and is particularly unlikely to see a quake of the magnitude of the one that hit Japan. Sitting more than 100 miles away from the sea, Vogtle also isn't likely to see a tsunami, although Terrell said that threat was also evaluated as part of its licensing process.

Terrell said the company does "not anticipate the events in Japan to impact the construction of our new units at Plant Vogtle, either in terms of its schedule or its costs."

He added that the company's reactors, like those in Japan, have both diesel generator back-up power and some battery power available to pump water to cool the reactor core. The planned new reactors also have a three-day supply of emergency water sitting on top of the reactor core, able tocool fuel rods without electricity.

U.S. Sen. Saxby Chambliss, R-Ga., said he has faith in Georgia's nuclear industry. "Georgia’s nuclear plants have the latest technology in place and the tragic scenario of a major earthquake and tsunami that occurred in Japan cannot be replicated in Georgia,” he said in an emailed statement.

Standard & Poors analyst Aneesh Prabhu, among those who tuned in to the NEI conference, said he came away convinced that the risks are low at a site like Plant Vogtle.

"That being said," he said, "the risk has been exposed. It has a small probability and a huge impact. I wouldn't be surprised if this delayed licensing."

Jay Hakes, former director of the federal Energy Information Administration, said the effect of the Japanese disaster will depend on what happens next.  "[If] they can survive this extreme event without blowing, there's an argument that it might even be a positive for the industry," he said.

Hakes headed the probe of another energy disaster  -- the 2010 BP oil spill --  and concluded that the oil industry should emulate the nuclear industry.

"We were basically of the opinion that they had become a model of self-policing and putting a very strong emphasis on safety," he said.