To fabricate the uranium and plutonium from reprocessing and use them in fuel is difficult "because plutonium is hazardous. It requires special equipment, a special facility that's very expensive."

Even if the plutonium were free, he said, the cost of using this reprocessed fuel would be greater than buying fresh uranium for the plants.

Cost also is a concern for Frank von Hippel, professor of public and international affairs at Princeton University and co-director of Princeton's Program on Science and Global Security.

He said that in the 1960s and '70s, the United States promoted reprocessing but later reversed that stance. That happened after India used reprocessing to separate plutonium from nuclear fuel — then used the plutonium for its first nuclear bomb, he said.

Also, he said, America's leaders decided it was not economical to reprocess and recycle plutonium. "That was confirmed by other countries' later experience," von Hippel said in a telephone interview, "countries that didn't stop as quickly as we did."

According to von Hippel, "We're talking in the ballpark of $100 billion for reprocessing and recycling," as well as preparing material for storage. That is the waste already generated, not counting future waste, he said.

"That's probably the low end of the range," von Hippel added.

"Recycling makes good sense for a number of reasons," Greg Hopkins, senior vice president of EnergySolutions, said in response to e-mailed questions.

"When taken on a life-cycle basis, considering the value of energy recovered and the disposal costs saved, it's economic. Recycling will also allow for the increased use of nuclear power for energy generation."

He said that presently, 20 percent of the U.S. power supply is derived from nuclear generation stations.

"There will be reduction in societal costs that are significant, but hard to calculate, with more nuclear generation." More nuclear power could reduce the need to import foreign fuel, resulting in greater energy security and energy independence, he said.

Not depending as much on burning fossil fuel means "a reduction in the amount of greenhouse gases emitted into the atmosphere," Hopkins said.

Problems in Britain

Serious accidents have plagued nuclear fuel reprocessing in Great Britain.

In May 2005, the British Health Protection Agency's Radiation Protection Division issued a report summing up the risks to the country's population from ionizing radiation from all sources, including medical X-rays. It concluded that risk from non-medical sources were "at a very low level."