EnergySolutions won't be able to bring more depleted uranium to Utah until the company proves the waste can be safely disposed in Tooele County for the long run.

That's what the Utah Radiation Control Board decided Tuesday by sticking to principles it adopted last month, even after the company threatened legal action.

The limit on DU, as depleted uranium is often called, does not go into effect for several months, and that leaves open a window for EnergySolutions to bring up to 15,000 drums of it from a government cleanup in South Carolina. But board members said their action Tuesday actually gets the safeguard in place sooner than originally expected.

EnergySolutions sent its attorney to the board meeting Tuesday to warn of potential legal consequences if the board did not backtrack on actions taken at its October meeting.

Board members deliberated for an hour in a closed-door meeting before voting unanimously to adopt a license change EnergySolutions' lawyer advocated and rescinded the vote last month that led to what the company called "a de facto moratorium" on DU.

But the board retained the safety report requirement, enacting it as a regulation rather than as a license amendment that EnergySolutions had opposed. Amending the license might have taken years, while the regulation is expected to go into effect in from 90 to 120 days.

Once finalized, the provision would bar future shipments of depleted uranium to the company's Tooele County radioactive waste landfill until the state determines large quantities of DU will be safe even when the waste reaches its most-hazardous levels in about 1 million years. EnergySolutions says developing the required report could take a year.

"We gave them what they wanted," said board Chairman Peter Jenkins. "But we also accomplished the protections we were looking for."

EnergySolutions released statements after the vote that praised the board for following the licensing and regulation processes set out by the Legislature.

One said: "The board has properly evaluated the safety and technical arguments made by the Nuclear Regulatory Commission and concerned citizens."

And the other: "We look forward to reviewing and commenting on the board's technical basis for developing the new rules."

The company and its attorney Craig D. Galli repeatedly said federal regulators had already deemed DU safe for the Tooele landfill.

But board members and members of the public noted that the NRC is doing its own review of above-ground disposal of DU in large amounts. They say they want to be sure the site will be safe and the radioactive hazard does not spread throughout the Great Salt Lake basin when the lake rises as it does every few thousand years and inundates the disposal site.

Tooele County resident Teresa Tate told the board during a public comment period that the site is "in my backyard," so the board's decision would affect her family and future generations.

"If it's so safe," she asked board members, "why does it have to move anywhere, ever?"

fahys@sltrib.com