Some environmental groups see a silver lining in the $700 billion financial bailout that is stalled in Congress, asserting the eye-popping price tag could help derail the development of another costly investment: nuclear energy.

A new Internet ad by Friends of the Earth warns that the nuclear industry is requesting a “pre-emptive bailout” from Congress by seeking more money to build new nuclear power plants.

A nuclear plant can easily cost $6 billion to $8 billion, according to the industry trade group, the Nuclear Energy Institute. And green groups point to a Government Accountability Office report that predicts the risk of default on nuclear loan guarantees to be “well above 50 percent.”

So Friends of the Earth is using the financial crisis to warn voters that investing in costly nuclear plants could result in the taxpayer bailout of another industry if nuclear companies default. Instead, the environmentalists hope lawmakers will consider wind, solar and other renewable energies that the groups say are safer and less expensive.

The bailout already has the presidential candidates talking about scaling back their energy wish lists. Democrat Barack Obama has acknowledged that the bailout plan could cause him to trim his energy investment plans, but he has not specified which areas. And Republican John McCain said he would slash subsidies for corn ethanol but has said nothing about scaling back his costly nuclear plan.

McCain has proposed building 45 nuclear reactors by 2030 to help move the country away from foreign oil — an ambitious project that could reach $360 billion. Ultimately, McCain wants to build 100 plants, which would cost $800 billion in today’s dollars — $100 billion more than the proposed Wall Street rescue plan.

“Basically we’re trying to lay the groundwork for the energy debate next year,” said Friends of the Earth spokesman Nick Berning. “We think the bailout changes the playing field. After this, does it really make sense to bail out the nuclear industry, too?”

The group points to a historic default made by the Washington Public Power Supply System, which undertook public funding to build five nuclear power plants in the late 1970s.

In 1983, it defaulted on $2.25 billion in municipal bonds after cost overruns and delays resulted in two canceled plants and halted construction on another two. Nicknamed Whoops, the poorly managed project resulted in the largest municipal bond default in U.S. history, and state taxpayers continue to pay the price.

Wall Street has balked at investing in nuclear plant construction because of the risk, and banks have warned the administration that the industry would not be backed without substantial federal support.

The Energy Department has reported that the first 75 reactors built in the United States took much longer to build than expected and suffered from more than $100 billion in cost overruns.

But the nuclear industry lobby says it is not concerned about being tied to the bailout. The industry spent more than $1.1 million lobbying on energy and nuclear issues so far this year and has many high-powered supporters in both the House and the Senate, including House Majority Whip Jim Clyburn (D-S.C.) and Sen. Pete V. Domenici of New Mexico, the ranking Republican on the Senate Energy and Natural Resources Committee.

The industry has billed itself as a ready-to-go alternative to fossil fuels with extremely low carbon emissions to create America’s electricity. Currently, there are 104 nuclear power reactors in the country, generating about 20 percent of its electricity.

The trade group would like to have four to eight new plants operating by 2016, a goal it says will require larger government loan guarantees.

The nuclear industry recently received $18.5 billion in federal loan guarantees — enough support, industry experts say, to build about three plants. The loan guarantees were a fraction of the nearly $50 billion that the industry had sought.

So far, the Nuclear Regulatory Commission said this week, 15 entities have applied to build and operate 24 plants, most of which won’t be built until at least 2015. The application alone, according to the NRC, costs an average of $22 million and takes 80,000 hours to process.

“We can all hope the economic mess will be sorted out by then,” said Nuclear Energy Institute spokesman Steven Kerekes. “We very much believe that to sustain projects at the level needed to address this country’s energy and environmental goals, there needs to be a larger loan guarantee in place.”

The industry argues that renewable energy projects such as wind and geothermal projects could just as easily put taxpayer money at risk. Last year’s energy legislation also gave $10 billion in loan guarantees for the renewable industry.

While a wind farm, for instance, could cost under $1 billion to build, nuclear reactors produce more electricity, lobbyists argue.

Many Capitol Hill energy experts said it was too early to predict how the bailout might affect future energy legislation. But Matt Letourneau, the Republican communications director for the Senate Energy Committee, said nuclear loan guarantees would not put taxpayer money at risk.

Loan guarantees provide government backing when a company takes out a loan. Every company is required to pay a subsidy cost, equal to a small percentage of the total loan. The funds are meant to cover the government in case the company defaults, and many don’t, Letourneau said. That leaves the government with an accumulating pile of money to handle major defaults.

“Calling loan guarantees a ‘bailout’ doesn’t even pass the laugh test,” Letourneau said. “The loan guarantee program doesn’t put taxpayers at risk because of the risk premiums companies pay.”

But a series of GAO reports last year found that the subsidy fee a company pays could be much less than the actual cost of a default, which would leave taxpayers to cover the difference. In the case of a failed nuclear plant, that could cost taxpayers billions of dollars, environmental groups argue.

“If you look at the track record of these corporations and look at the track record of the nuclear industry, you wouldn’t want to invest your money in this business,” said Greenpeace nuclear policy analyst Jim Riccio. “And taxpayers will not want to be put on the hook again.”