The Senate endorsed a plan Tuesday for the government to provide loan guarantees for construction of a half dozen nuclear power plants that supporters say are necessary for the industry's survival.

Critics called the government assistance a giveaway to a mature industry that should be left to succeed or fail on its own. But their attempt to strip the measure from a broad energy bill fell short, 50-48.

Sen. Pete Domenici (search), R-N.M., the architect of the package of subsidies for the nuclear industry, said the government assistance will jump-start nuclear power. There has not been a new nuclear plant licensed since the 1979 accident at the Three Mile Island (search) reactor in Pennsylvania.

"The time has come to quit playing around with energy and say, wherever we can, we are going to produce more energy," argued Domenici. Nuclear power has long been neglected, he said, and that has been "a giant mistake."

Opponents questioned why nuclear power should be singled out for such largess, which they said could cost taxpayers $14 billion to $16 billion should the future power reactors fail and be abandoned.

It's "not a question about whether someone is pro-nuclear or anti-nuclear," argued Sen. Ron Wyden, D-Ore., one of the provision's sharpest critics, but whether "to put at risk the taxpayers of this country" if the reactor projects flop.

Sen. John Sununu, R-N.H., co-sponsor with Wyden of the effort to scuttle the loan guarantees, said he supports a broad array of energy sources, including nuclear, but "power plants should be developed on a level playing field without government subsidizing one industry over another."

He said he also opposes a $2 billion subsidy to develop clean coal plants, also in the energy legislation that Domenici hopes to get through the Senate in the coming weeks. An energy bill already passed by the House contains far less help for the nuclear industry and does little to spur new reactor construction.

In separate action Tuesday, the Senate by a 99-1 vote included in the energy bill a measure requiring that the president take action to save 1 million barrels of oil a day by 2013. The measure did not specify how the reduction in consumption, compared to what it otherwise is projected to be in 2013, is to be achieved. The country currently uses about 19 million barrels of oil a day.

In the most ambitious attempt to spur nuclear power development in decades, Domenici put into the Senate bill measures that would:

-- Have the government provide loan guarantees to cover half the cost of building enough new reactors to produce 8,400 megawatts of power. That would probably be as many as six or seven next-generation reactors.

-- Build a $1.1 billion reactor in Idaho to produce hydrogen.

-- Authorize $865 million to speed research into ways to alter reactor waste chemically to reduce its volume and long-term radioactivity.

-- Increase other nuclear research spending by tens of millions of dollars over current levels.

Supporters of the measure argued that the energy bill provides loan guarantees to other energy sources, including a proposal in the bill that would underwrite loans covering as much as $18 billion of a $20 billion Alaska pipeline to bring natural gas down from the North Slope.

In case of the nuclear reactors, taxpayers wouldn't pay a dime if the plants should succeed but would be liable for billions of dollars should they fail.

Wyden cited an analysis from the Congressional Budget Office (search) that estimated the new plants probably will cost $2.1 billion to $3 billion apiece with "the risk of default on such a loan guarantee to be very high -- well above 50 percent."

Nuclear industry representatives called the CBO analysis flawed and said that companies wouldn't pursue reactor projects unless there was almost certain likelihood of success because they would be on the hook for half of the cost if there is a default.

The new plants would be built under regulations that removed many of the past licensing hurdles and would be far cheaper than that last reactors built.

"We're trying to jump-start the industry again," says Richard Myers of the Nuclear Energy Institute, the industry trade group. "We're not looking for a handout. We're not looking for any freebies."