SALT LAKE CITY — Yet another delay is being encountered on the long and winding regulatory path that will determine if Utah becomes a key repository of the nation's supply of depleted uranium — low-level radioactive waste that becomes increasingly potent over millions of years.
The Utah Department of Environmental Quality just received this week additional information from EnergySolutions related to potential erosion and other "deep time" problems suspected to impact its Tooele County disposal site, pushing back the start of a public review to April 13.
Helge Gabert, project manager for the state on the depleted uranium issue, said the requested information was about a month late. It was submitted Wednesday for review. It will be incorporated into a subsequent analysis or safety evaluation that the agency will release for public comment about a week beyond its earlier time frame.
In addition, a pair of public meetings will be held the week of May 4, with a decision on disposal due July 1 from Rusty Lundberg, director of the Utah Division of Radiation Control.
To take the nation's leftovers of 750,000 metric tons of depleted uranium, EnergySolutions has to first convince Utah regulators that its site will be safe for 10,000 years. Beyond that, it has to prove that the threat to public health will be minimal in the advent of a return of a Lake Bonneville or other "deep time geologic events" over 2.1 million years.
It is a mind boggling scenario, planning for all manner of circumstances that could play out, modeling time and performance over such an extended period that it is difficult to grasp.
EnergySolutions must account for the farmer who wanders onto the disposal site, unaware of the radiological hazard underneath his feet. Or the burrowing rodent that could cause vulnerabilities to the at-grade disposal site.
The company must try to figure out how the wind will deposit the sand, how dunes will form and when the lake returns — as some say it inevitably will — how the water might disperse the radiological hazard from an anticipated breach of the disposal barrier.
Such planning is something Utah is requiring because of the unique nature of depleted uranium, which is the byproduct of the uranium enrichment process for nuclear fuel. While depleted uranium has commercial applications, such as antitank armaments, demand for it is far outpaced by the amount that is generated. The U.S. Department of Energy has responsibility for its disposal.
Depleted uranium gets more radioactive as its isotopes try to get back to their natural state, and as these "daughter products" break down, they not only multiply, but increase in intensity.
The instability that occurs in the decay process occurs over 2.1 million years, with what was once classified as "low-level" radioactive waste breaching Utah-imposed limits on what is allowed to be buried in the state.
Gabert said there is no question that by 40,000 years, depleted uranium will violate the state's prohibition on anything "hotter" than Class A waste, so it becomes a policy issue for current regulators to decide if its disposal is acceptable in the here and now.
"You could argue why does not the state just make the decision based on the science, but we have not made that. We are willing to hear out what the facility has to say," Gabert said.
The deep time analysis looks in particular if the threat will be mitigated enough — if the doses of radioactivity would be diluted to the degree that even exposure to a higher "category" of waste would not cause harm.
Critics of the EnergySolutions' proposal to dispose of the depleted uranium say no amount of assurances or analysis can safeguard human health given the sheer amount of unknowns.
The concern prompted the intervention of Utah Gov. Gary Herbert after 5,400 drums — or 3,500 tons of depleted uranium — were shipped to Clive for disposal in December of 2009.
Herbert met with U.S. Department of Energy officials in Washington D.C., and convinced them to divert two other planned shipments to Utah from the federal Savannah River Site in South Carolina.
A subsequent analysis of the material already shipped to Utah revealed it met Class A limits, but it remains in above-ground storage while the analysis determines if Clive is suitable for long term disposal of the waste.
Because EnergySolutions is licensed as a commercial facility, it can take low-level radioactive waste generated on U.S. soil if it meets specifications under what is called the Northwest Compact and if Utah regulators don't act to impose new restrictions.
The company operates a site about 80 miles west of Salt Lake City in Tooele County, west of I-80.
Clive's disposal site has been licensed by the state to accept Class A waste since 1992, but it was under different ownership. So far, 205 million cubic feet of waste has been buried at the site. Gabert said if the depleted uranium is ultimately deemed acceptable for disposal, a new so-called federal cell would be constructed in the southwest corner, and the depleted uranium would occupy an estimated 20 percent of the entire area.
Farther away from home, the company is at the middle of a political controversy in South Carolina, where it wants to swap low-level radioactive waste in return for burying hotter waste at the Barnwell site it operates.
Current South Carolina law prohibits the disposal of any waste outside of the governing compact — meaning only waste generated in South Carolina, Vermont or Connecticut is eligible for disposal.
Under an arrangement being shopped before South Carolina legislators, EnergySolutions would ship low-level radioactive waste to Utah that had been bound for South Carolina. In return, South Carolina would receive the "hotter" waste for disposal there, generating more income for state coffers.
Utah's radiation chief Rusty Lundberg said the proposed trade is interesting, but it has no bearing on Utah because Clive is already eligible for out-of-state waste. None of the more radioactive waste would come to Utah under state prohibitions in place.