The decision ends about a year of suspense for EnergySolutions and its watchdogs, who insisted that the company's existing site-safety study did not adequately assess the possible new hazards posed by blended waste, which basically is a mixture of highly contaminated waste with less contaminated waste.
EnergySolutions entered into a joint venture about a year ago to take waste resins from nuclear reactors and blend them at a plant in Tennessee. When it comes out of that plant, the resulting waste has a hazard level low enough to meet Utah's limits and to be disposed of at the Tooele County disposal site.
The company argued in papers submitted last February that its disposal site can properly contain the hazard for thousands of years. Its hope was to open its site for more business from reactor operators who have had no way to get rid of their higher-hazard resins since 2008.
The company's license already allows the mile-square disposal site in Tooele County to take treated radioactive resins that meet the state's hazard limits. The issue in this case, regulators noted, is the large volumes the company has asked to bury.
"We recognize the Division of Radiation Control's determination to require an evaluation or new performance assessment regarding large scale blending," said company spokesman Mark Walker in an emailed statement. "We will comply with the DRC's request and expect to complete a new [performance assessment] within the one-year time frame required by the DRC."
The Radiation Division noted that federal and state standards have been changed since the company did a site-performance review in 2000. In the meantime, the state's Radiation Control Board has updated the requirements that apply in this case, and the U.S. Nuclear Regulatory Commission is expected to follow suit in a couple of years, the DRC said.
In a letter sent to the company Monday outlining their decision, state regulators told the company it may accept no more than 40,000 cubic feet of blended waste between now and the time its beefed-up site engineering study is completed.
EnergySolutions accepted 6.7 million cubic feet of waste overall for disposal last year, according to state documents provided to the Healthy Environment Alliance of Utah (HEAL).
EnergySolutions said it would begin offering the blending service to its customers with that limit in mind.
HEAL spokesman Matt Pacenza criticized the division's decision to allow the company to begin taking the treated waste before the engineering analysis is done.
"It's appalling that Utah regulators will allow significant quantities of hotter radioactive waste to come to the West Desert while they study whether it's safe to dump it here or not," he said.
"Governor Herbert and state regulators have strong grounds on which to reject this dangerous nuclear waste right now," he added. "Letting EnergySolutions start dumping it while you're trying to figure out whether it's safe or not is bad policy."
Read the letter