The federal government is in search of trains for hauling radioactive waste from nuclear power plants to disposal sites -- even though the waste locations haven't actually been found yet.

Companies were recently asked by the United States Department of Energy for ideas on how the government should acquire rail cars for transporting150-ton casks filled with used, radioactive nuclear fuel, according to a report by the Associated Press.

Yet, the government's latest plans are for establishing an interim test storage site by 2021 and a long-term geologic depository in 2048.

The Obama administration apparently has no idea where those waste facilities will be sited, but is nonetheless anticipating contracts to develop, test and certify the rail equipment needed for the hazardous hauls.

Energy Department officials -- who recently asked for public feedback on whether they should should buy or lease the rail cars -- did not return messages from the AP seeking detailed comment for the story.

Previous communications from the department demonstrate it expects the sought rail cars to last up to 30 years, run at standard speeds on regular tracks, accommodate the heavy protective casks necessary as nuclear shielding and run up to eight times each year.

The military already sends fuel by rail from its reactors on Navy ships to federal labs for storage and the civilian power industry shipping more than 2,300 tons by rail from 1979 to 2007.

One of the biggest rail shippers of nuclear waste has been Progress Energy, moving spent fuel from two of its plants to a third plant in North Carolina.

The rail shipments sparked protests and appeals from environmental groups and local governments, and the company announced in 2003 it would halt those shipments after building land-based storage facilities at its other plants, eliminating the need for the transfers.

Tracks for the nuclear waste trains were supposed to lead to a depository at Yucca Mountain in Nevada, where Congress intended to send radioactive fuel.

But, the Obama administration canceled the depository construction project after it had been criticized as inadequate and opposed by many Nevadans.

The U.S. government is by law responsible for nuclear fuel disposal and once charged electric customers to fund its work. The Energy Department quit collecting that fee this year, after it was taken to court.

Meanwhile, nuclear industry observers are praising even the limited signs of forward movement from the government, even if it's only a matter of eyeballing trains.

"This is a good timing," said Everett Redmond, who works on waste policy for the Nuclear Energy Institute, an industry lobbying group. "You don't want to wait until you're close to opening the facility to try and design a rail car."

The U.S. Nuclear Regulatory Commission and Department of Transportation share responsibility for regulating shipments of nuclear waste.