SALT LAKE CITY — When figuring out if it is going to be safe to allow large quantities of depleted uranium to be buried in the desert 65 miles west of Salt Lake City, the state of Utah has to contemplate a long list of "what ifs" that could happen — and over a long, long period of time.
There are events like war, meteor strikes, volcanic activity, the return of large lakes like Lake Bonneville every 16,000 years and even, to some degree, the threat to stable disposal caused by burrowing ants.
EnergySolutions is proposing to dispose of 3,507 metric tons of depleted uranium at Clive, Tooele County, and it could be the nation's repository of its inventory of 700,000 more tons of the radioactive waste, which is a byproduct of nuclear production material.
The state has to sign off on the disposal, requiring the company to complete a "performance assessment" that looks at how well its disposal site will weather all sorts of events and conditions.
To explain the process and help guide the public in its understanding of the analysis, the state Division of Radiation Control is hosting an open house from 4 to 6 p.m. Wednesday in the conference room at the Multi State Agency Office Building, 195 N. 1950 West.
Rusty Lundberg, division director, said the informal event is the first of several efforts by the agency to explain the issue in advance of any decision that will be made regarding EnergySolutions' request.
"We are taking this initial step to help the public understand what the intent of this is, what its purpose is," he said. "We're taking this initial first step to inform the public."
The prospect of Utah receiving the unique waste stream has been a contentious and complicated issue for regulators, who have had to grapple with the idiosyncracies of possibly receiving such a unique waste stream.
Even the federal regulators — the Nuclear Regulatory Commission — have yet to craft a rule on the storage of this brand of radioactive waste, leaving Utah to forge out on its own with building a framework that is protective of public health and the environment.
Depleted uranium falls within the radioactive levels Utah has established by law that it is willing to accept — low level radioactive waste — described as Class A. "Hotter" wastes such as B and C are prohibited.
The problem posed by the storage of depleted uranium stems from its increasing radioactivity — it continues to get "hotter" over time, peaking at 2.1 million years and staying at the level for billions of more years.
Utah regulators required EnergySolutions to come up with contingencies in its storage plans that document how its site would fare for a period of 10,000 years — and beyond that looking at "deep time" scenarios until it reaches peak radioactive levels.
The scenarios contemplate vulnerabilities to the public — from off-highway vehicle users who recreate nearby in Tooele County, military at the Utah Test and Training Range and the lone resident caretaker at the rest stop off I-80 at the Aragonite exit.
Neptune and Co. was hired by EnergySolutions to conduct the assessment, ultimately settling on 135 "unique groupings" of risks that spanned all manner of probabilities.
Lundberg said that is what is key for the public to understand — the purpose and scope of the assessment — which deals in probabilities and not determinations.
"This assessment informs our decision on depleted uranium, it does not make the decision," he said.
The division will soon begin reviewing the assessment and is expected to make a decision next fall.