WASHINGTON (Reuters) - President Barack Obama announced $8.3 billion in loan guarantees Tuesday to build the first U.S. nuclear power plant in nearly three decades, a move designed to help advance climate legislation in Congress.

Obama, a Democrat trying to win Republican support for a bill to overhaul U.S. energy practices, said the United States needed to increase its supply of nuclear power to meet its energy needs and fight climate change.

The government backing will go to help Southern Co build two reactors at a plant in the state of Georgia. The reactors, which some experts estimate will cost $8.8 billion, could be in service in 2016 and 2017.

“Even though we’ve not broken ground on a ... new nuclear power plant in 30 years, nuclear energy remains our largest source of fuel that produces no carbon emissions,” Obama said after touring a union education center in Lanham, Maryland.

“To meet our growing energy needs and prevent the worst consequences of climate change, we’ll need to increase our supply of nuclear power. It’s that simple.”

Obama is pushing for a law that would cap greenhouse gas emissions from industry and expand the use of renewable fuel sources such as wind and solar.

By reaching out to Republicans on the nuclear issue -- a top priority for key opposition lawmakers such as former presidential candidate John McCain -- the Obama administration hopes support for the stalled climate bill will grow.

That hope may not come to fruition.

Republicans are eager to expand nuclear power and offshore drilling but are resistant to Obama’s proposal for a greenhouse gas emissions trading system similar to the European Union’s.

Still, aid to the nuclear industry could draw support for the climate bill from states in the South and Midwest with huge utility companies that run plants on both nuclear and coal.

Obama said the climate bill, which contains a cap-and-trade system, would help create incentives for cleaner fuels such as nuclear. He said his administration would work to develop what he saw as common ground on the bill with Republicans.

“We’re not going to achieve a big boost in nuclear capacity unless we also create a system of incentives to make clean energy profitable,” Obama said.

“As long as producing carbon pollution carries no cost, traditional plants that use fossil fuels will be more cost-effective than plants that use nuclear fuel.”

Shares in Southern Co surged 2.28 percent on the news of the loan guarantees. The Atlanta-based company has one of the largest number of coal-fired power plants in the United States and would suffer if Washington were to institute restrictions on carbon dioxide emissions.

Nuclear power generating companies also rose on the news, with Exelon Corp up 2.08 percent and Entergy up 1.85 percent.

U.S. Energy Secretary Steven Chu said the department plans to offer loan guarantees to at least half a dozen projects but declined to lay out a timeframe for further announcements.

President Obama speaks during a visit to a training center at the International Brotherhood of Electrical Workers (IBEW) Local 26 Headquarters in Lanham, Maryland, February 16, 2010. REUTERS/Kevin Lamarque

EPA FIGHT GETS UGLY

Democrats and opposition Republicans are at odds over several aspects of how to fight climate change.

Senator Lisa Murkowski of Alaska is spearheading legislation that would prevent the Environmental Protection Agency having the power to regulate greenhouse gases -- an option Obama is preserving if Congress does not act.

Other entities -- including Texas, the U.S. Chamber of Commerce and the American Iron and Steel Institute -- are initiating legal challenges to stop the EPA from acting unilaterally on greenhouse emissions.

Carol Browner, Obama’s top energy and climate advisor, said the White House would oppose any move to limit the EPA’s regulatory authority.

“We will work against that. We do not want to see that passed,” she told Reuters Insider in an interview.

Expanding nuclear energy is one area Obama and Republicans have embraced as a way to generate power and create jobs.

The administration said the project would generate 3,500 construction jobs and 800 permanent positions once the reactors go into operation.

Supporters of nuclear power argue more reactors will be needed for the United States to tackle global warming effectively because nuclear is a much cleaner energy source than coal-fired power plants, which spew greenhouse gases.

But nuclear power is controversial because of its radioactive waste, which is now stored on site at reactor locations around the country. Remembering the 1979 accident at the Three Mile Island nuclear power plant in Pennsylvania, many Americans still harbor concerns about nuclear power’s safety.

Obama said a commission with Republican and Democratic leaders and nuclear experts was examining the waste issue.

Some environmental groups also fret that too much effort is being spent on costly, old technology instead of renewable energy sources.

“Unfortunately, the president is setting up the American taxpayer for the next corporate bailout,” said Jim Riccio, nuclear policy analyst for Greenpeace, saying the Congressional Budget Office has already determined the loans stand a greater than 50 percent chance of default.