Depleted uranium is not your ordinary radioactive waste.

Most hot waste gets less hazardous over time, like most of the stuff buried at EnergySolutions Inc.'s disposal site in Tooele County.

But not DU, as it's called. The uranium enrichment by-product becomes more hazardous as it decays. And that's the reason the U.S. Nuclear Regulatory Commission's latest decision on depleted uranium is causing such a controversy.

On Wednesday, the commission voted 3-to-1 to regulate DU as Class A low-level waste. And, in doing so, it made up to 1.4 million tons of DU potentially eligible to go to EnergySolutions' Utah site.

While the Salt Lake City nuclear company is applauding the decision, critics say the NRC has put industry's interests before people. And the commissioner who cast the "no" vote said DU is "a unique challenge" that deserves its own category.

Instead, the NRC ruling directs staff to suggest any extra precautions -- like a heavier radon barrier or deeper burial -- needed before DU gets buried at any disposal site.

"I'm hopeful in the end that we will come up with what a safe disposal methodology for this material would be," said Commissioner Gregory B. Jaczko, who's been pushing NRC to be clearer and more open about radioactive waste.

For EnergySolutions, the ruling clears the way for lots more of a waste stream it's already been taking on a much smaller scale. It also solves a problem for the blossoming uranium enrichment industry, which would have had no disposal options if NRC had labeled DU differently, because hotter waste is not permitted in Utah.

Said company spokesman Mark Walker: "We appreciate the NRC's ruling which is based on sound science that depleted uranium is Class A waste."

But Christopher Thomas, policy director of the Healthy Environment Alliance of Utah said DU is a radioactive threat that grows for hundreds and thousands of years.

"Ultimately, it'd be too hot for Utah to handle," he said. "The NRC is tearing a hole in the waste classification system that is supposed to protect us. Their decision puts the interests of EnergySolutions and the nuclear industry ahead of the health and safety of Utah."

Anti-nuclear groups have said DU is 40 times more radioactive than typical Class A waste and is four times more hazardous than some types of plutonium. They said it needs to be secure for thousands of years -- far longer than the 100-year hazard limit for Class A waste.

Arjun Makhijani, president of the Institute for Energy and Environmental Research, praised Jaczko and attacked the scientific integrity of NRC's ruling.

"The NRC seems eager to please the burgeoning uranium enrichment industry," said Makhijani, "but it has compromised sound science and public health protection of future generations."

Dane Finerfrock, director of Utah's Division of Radiation Control, noted one key factor for the state will be how long the NRC's hazard limits will apply. For instance, a certain concentration of DU might not be dangerous in 100 years or 1,000 years but might be far more hazardous in 10,000 years from now.

Whatever NRC decides, safety standards will have to be met, he said. "We'll do exactly what the rule requires us to do."

fahys@sltrib.com

{Depleted uranium (DU) is a uranium enrichment by-product. Unlike most hot waste, DU becomes more hazardous as it decays.Anti-nuclear groups have said DU is 40 times more radioactive than typical Class A waste and is four times more hazardous than some types of plutonium.}

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