For its part, EnergySolutions says critics misrepresent how much material would be ultimately disposed of in Utah. Most material would be recycled or incinerated at its plant in Tennessee. Just 8 percent — about 1,600 tons — of the original volume would travel to Utah, the company wrote in a letter to the NRC.

"EnergySolutions does not believe the United States should be responsible for the world's nuclear waste," company spokesman Mark Walker writes in response to e-mailed questions from a reporter. But as reliance on nuclear power grows worldwide, "the U.S. is in a leadership role to provide technical solutions."

The company "has no plans" to open its Utah disposal site "to wholesale disposal for the world's nuclear waste," Walker writes. But in a recent prospectus, the company envisions "specialized decommissioning and disposal services" for Europe and the United Kingdom.

Critics say import regulations are weak because Congress never foresaw that the United States would import large volumes of radioactive waste.

"There is no indication in (legislative action or NRC regulatory action) that there was any intention that the United States would ever become a welcome repository of foreign-generated radioactive waste," Gordon, D-Tenn., chairman of the House Committee on Science and Technology, wrote to Klein, the NRC chairman.

While the United States has long permitted low-level radioactive waste imports, most have been small compared with the EnergySolutions request. Of 24 such waste-import license applications over the years, NRC records show 13 granted, according to an analysis by the House committee.

EnergySolutions says its plan is not out of line with past licenses. The company cites a 2006 license to import 6,000 tons of waste from Canada — about one-third the size of its Italy request. The Tennessee facility also has a history of processing materials from Germany, Belgium and the United Kingdom, and accepting waste from Italy would be business as usual, the company says.

New dynamic

"All waste streams raise concerns about risks suffered by local communities," Matheson said in his letter to Klein. "Adding additional streams of waste from international sites would serve only to compound the risks."

Matheson also told the Deseret Morning News Thursday that while he opposes the waste coming to Utah, the issue goes beyond just this license application.

"Are we going to be accepting nuclear waste from the rest of the world?" said Matheson, who sits on the House Energy and Commerce Committee, which would be a starting point for legislation regarding nuclear waste. "The whole congressional discussion never included foreign waste. This is a whole new dynamic."