But Senate Minority Leader Harry Reid of Nevada, an adamant opponent of the project, said the facility is "not even on a life support system."

"It's dead when it gets here," Reid told reporters.

Energy Department officials said the proposed legislation would not answer the thorny question of when the underground waste dump about 90 miles (150 km) northwest of Las Vegas would open its doors to accept waste from the 103 US nuclear power plants.

The project, more than 10 years behind schedule, is still plagued by scientific foul-ups and political stonewalling.

Republican Pete Domenici, chairman of the Senate Energy Committee and a nuclear industry proponent, said he will shepherd the bill through the Senate for the administration.

The proposal would eliminate the current 77,000-ton limit (70,000 metric tons) on waste allowed at the site, and allow shipments to rise to their technical capacity of 132,000 tons (120,000 metric tons), Energy Department officials said.

The administration proposal would also reserve about 147,000 acres of federally owned land to build a railway corridor to transport spent fuel to the Yucca Mountain site.

The Nuclear Energy Institute, which lobbies for nuclear operators, said that unless the storage limit was raised the repository would be fully allocated before the first shipment arrived.

Spent fuel from the nation's nuclear plants -- which supply about 20 percent of US electricity -- is piling up, with over 50,000 tons (45,500 metric tons) of it stored at over 100 temporary locations in 39 states.

The Energy Department gave no date certain for when it will send its application to build the repository to the Nuclear Regulatory Commission, a key regulatory step.

Paul Golan, acting director of the Energy Department's Office of Civilian Radioactive Waste Management, said the department will set an NRC application schedule this summer.

After receiving the application, the NRC would have up to four years to review it on safety grounds. Then, it would take the Energy Department and its contractors up to four years to build the site, department officials said.

The final step would be for the NRC to give the Energy Department final authorization to accept waste from nuclear operators, which would take up to 18 months under the administration's new proposal.

If the Energy Department sends its application to the NRC by the end of the year, its current schedule suggests that Yucca Mountain could begin accepting waste sometime in 2016.