The first nuclear reactor in the United States went online at Shippingport, Pa., in 1956. Since then, the nation’s nuclear power industry has generated at least a few hundred tons of spent fuel per year. The highly radioactive waste is too unstable to reliably power a reactor, but potentially deadly for thousands of years to come. Add to that the waste from research reactors, national laboratories and military sites, and America in 2006 has nearly 50,000 tons of hot toxic junk on its hands. That’s enough to fill a football field six yards deep, or, well, Yucca Mountain — the only site Congress has approved for the underground disposal of nuclear waste, despite evidence that the earthquake-prone site (5.2 in 1992, 4.0 in 2002), may lie precariously near a volcano.

The U.S. Department of Energy predicts Yucca Mountain will open in 2017, 19 years later than planned. Until then, most used-up nuclear fuel will continue to sit in storage pools alongside various reactors — which the National Academy of Scientists has warned are vulnerable to terrorist attack — or in concrete casks on site, awaiting transport to a geologic repository. Waste disposal remains the nuclear industry’s Achilles’ heel — without a solution, the nuclear power renaissance may never amount to more than an idea.

With that in mind, last winter the Bush administration asked legislators to set aside a significant chunk of federal money for new research into recycling and reprocessing spent nuclear fuel. "This will allow us to produce more energy, while dramatically reducing the amount of nuclear waste," Bush declared last February, promoting a quarter-of-a-billion-dollar funding initiative for nuclear waste reprocessing.

It’s not hard to understand the allure. This, after all, is how the French have managed their waste since 1976, processing each type of waste individually at their La Hague plant to reduce the total amount by 75 to 95 percent.

During nuclear power generation, fissionable uranium (U-235) is shot with neutrons, causing its atoms to split. The uranium transforms into other elements, such as nonfissionable U-238, plutonium-239, americium, strontium-90 and tritium. These leftover elements can either remain together in one solid chunk of conventional waste, or be "reprocessed": separated by dissolving the elements in a chemical bath. Five to 25 percent of this separated material remains high-level waste, and goes through a process called "vitrification" to turn it into compact glass bricks for storage in a Yucca-Mountain-like facility. But some can be reused: Tritium in gun sights, americium in smoke detectors, strontium-90 in cancer treatments. Plutonium-239 can be blended with enriched uranium to produce mixed-oxide fuel for reactors, making reprocessing attractive to those who worry that the price of uranium will soar further if nuclear power ever fully returns to favor.

But plutonium can also be used to make bombs. And it’s easy to steal: Unlike the gamma-ray emitting elements in enriched uranium that can penetrate your skin, plutonium emits only weak alpha rays, which a thin sheet of paper will block. Breathe it or eat it, and you die; filch a little from the recycling bin, and you can carry it away in your pocket. And therein lies the trouble with reprocessing, the reason President Gerald Ford put a moratorium on it in 1979 and President Carter banned it one year later, and the reason a House subcommittee responded to Bush’s appeal for reprocessing research dollars by slashing his proposed budget by more than half.

That’s not all: European reprocessing facilities — which, like nuclear power plants, use large amounts of water as coolant — fail to meet the discharge standards of the U.S. Clean Water Act. The French dump millions of tons of effluent every year from their reprocessing facilities into the English Channel, as do the British from their notoriously beleaguered Thorp reprocessing plant, where a significant leak in 2005 went undetected for several months.

This summer, however, the Senate approved the administration’s entire $250 million budget request for further investigation into nuclear reprocessing. Now all that’s left is to pound out a compromise between the Senate’s full approval and the House’s proposed cuts. But given the technology’s messy history, any money allocated for it will likely meet the same fate as the $8 billion poured into studying Yucca Mountain: Gone, quite literally, to waste, without ever finding a solution to nuclear power’s most fundamental flaw.