WASHINGTON -- The Department of Energy on Monday proposed new spending to get Yucca Mountain on track, with a top official saying it could be possible eventually to reprocess nuclear waste at the Nevada site.

The comment by DOE Deputy Secretary Clay Sell marked the first time a government official has publicly mentioned the idea of locating a reprocessing plant at Yucca Mountain, a Nevada leader said, raising a potential new issue for debate over the proposed waste repository.

Energy Secretary Samuel Bodman and Sell, the department's No. 2 leader, pledged renewed commitment to the delayed Yucca project during announcements about DOE's fiscal 2007 budget.

This time, support came in the context of a Global Nuclear Energy Partnership, or GNEP, an initiative the Bush administration believes has promise to spur the expansion of nuclear power not just in the United States but also in other countries.

At some point, Sell said during a briefing, reprocessing might make sense at Yucca Mountain, which is being designed to hold 77,000 tons of spent nuclear fuel.

"Once we get (Yucca Mountain) opened, then we can start moving spent fuel there," Sell said of the repository. "And we would certainly contemplate it as possible that fuel could move there and then be recycled."

Or, Sell said, the government might establish other "recycling centers" for nuclear waste.

"I think there will be significant interest from various states in building these centers in which spent fuel would be staged there temporarily while it is in the process to be recycled and before it ultimately goes to Yucca Mountain for disposition," he said.

The Global Nuclear Energy Partnership envisions cooperation among the United States, Russia, France, Great Britain and other nuclear nations to perfect technologies that could reprocess spent nuclear fuel into reusable product without separating plutonium that could be used in nuclear weapons.

The United States abandoned waste reprocessing in the 1970s, citing the threat that technology then in use would encourage nuclear proliferation.

But the Bush administration maintains that advances within reach could reduce the proliferation threat and promote the expansion of nuclear power in the United States and nations hungry for electricity to fuel economic growth while reducing reliance on fossil fuels.

The proposal envisions selling fast reactors to smaller countries to burn spent fuel, leasing the fuel to participants, and then taking the spent fuel back for recycling and disposal.

Sell said it was an "open question" as to whether nuclear fuel burned overseas could be sent to the United States and buried at Yucca Mountain.

"It is dependent on a number of things, the development of the technology, international agreements, and other things," Sell said. " It is certainly possible that it could stay in a country where it is recycled and burned down, but it is also possible that it could go back to the user nation as well."

Also uncertain Monday was whether the government might have to redesign Yucca Mountain to accept reprocessed waste. Sell said it might.

But acting DOE nuclear waste director Paul Golan said Yucca Mountain is being designed to hold nuclear waste reprocessed at a now-closed facility in New York State and at government reservations in South Carolina and Washington state.

"Under today's scenario we are planning to put reprocessed waste into Yucca Mountain," Golan said. He added, however, that designs may be reviewed if estimated amounts expand and affect projections of the repository's performance.

Reprocessing is touted to reduce the volume and radiotoxicity of nuclear waste. DOE officials said the resulting byproducts could be disposed at Yucca Mountain within its capacity, avoiding the need to build more repositories through the end of the century, even as nuclear power and its waste products grow.

" It is our goal, with the GNEP initiative, to raise the level of debate and to make progress more quickly on Yucca Mountain than we have in the past," Sell said.

"Getting Yucca Mountain licensed, getting it opened and getting spent fuel moved is critical, we think, to the nuclear renaissance which we are on the cusp of in this country," Sell said.

The Bush administration plan has been challenged by organizations that question its costs and whether reprocessing truly can made be made safe from terrorists or rogue nations.

The National Academy of Sciences estimated in 1996 that reprocessing irradiated fuel from U.S. reactors would cost more than $100 billion, said Tyson Slocum, director of the Public Citizen Critical Mass Energy Program.

"GNEP cannot accomplish the administration's proliferation or waste management goals," Slocum said. "The reprocessing technologies that DOE is currently researching are far from 'proliferation-resistant' and are decades from commercialization."

The Bush budget unveiled Monday contains $250 million to initiate the Global Nuclear Energy Partnership. Sell said future costs are expected to be substantial but the administration was prepared to continue backing the proposal.

Rep. Shelley Berkley, D-Nev., said she opposed the plan, saying that material left over after reprocessing will still be dangerous and because it still calls for a repository to be build in Nevada.

"The nuclear industry is desperately peddling reprocessing as a solution for dealing with radioactive waste, but at the end of the day, all roads still lead back to Yucca Mountain," Berkley said.

Rep. Jim Gibbons, R-Nev., applauded the reprocessing initiative "as a step in the right direction." But he said he was disappointed that Bush has not severed the tie to Yucca Mountain.

"Certainly, the remaining waste could be safely stored on-site, and we can continue to invest in other technologies (such as transmutation and Thorium-based fuel) to reduce that waste even further," Gibbons said.

"Any proposed nuclear strategy that includes storing waste at Yucca Mountain is unsafe, illogical and unacceptable," said Rep. Jon Porter, R-Nev.

Sen. Harry Reid, D-Nev., said he took a dim view both of the new Yucca funding and the reprocessing plan.

"At a time when we're running record budget deficits, we cannot afford to spend hundreds of millions of dollars on dangerous, untested, or misguided projects," he said.

Bob Loux, director of the Nevada Agency for Nuclear Projects said the idea of reprocessing nuclear waste at the Yucca site has been mentioned privately by government and industry officials, but Sell's comment was the first public mention.

The Yucca repository is eight years behind its original 1998 target and DOE also abandoned a 2010 projected opening. Managers have not set new timetables as the program has confronted legal and technical obstacles in recent years.

In its proposed 2007 budget, DOE proposed $544.5 million in new spending at Yucca in the fiscal year 2007, an increase from the $450 million that Congress appropriated for the current year.

Within its budget plan, DOE proposed a 240 percent increase, from $19.9 million to $67.8 million, for engineers designing railroad cars and a rail route to ship waste across rural Nevada from Caliente to the Yucca site.