Some legislators and environmentalists want to know if International Uranium Corp.'s mill on White Mesa in southeastern Utah needs more regulatory controls and whether the uranium-processing mill sometimes functions as a radioactive-waste disposal site.

"This is a very, very complex area," says Gregory Bell, Senate chairman of the state Legislature's Public Utilities and Technology Interim Committee.

After two hours of discussion this past week, Bell, R-Fruit Heights, concluded, "We just wanted this on the radar screen so we could understand it further." No action was taken.

International Uranium has recently been on the hot seat with environmental groups over its current request for the White Mesa mill to be able to accept and process a new batch of "alternate feed" material, which the company describes as "uranium-bearing materials other than conventional ores." At least one more public hearing stands in the way of final approval for the request.

International Uranium Vice President David Frydenlund said his company is "strictly" regulated, although committee members questioned whether federal or state controls were more responsible for keeping mill operations in check.

Since it began operating in 1980, the White Mesa mill has processed over 3.8 million tons of ore to extract 28.5 million pounds of uranium — or "yellowcake" — used to fuel nuclear power plants that produce electricity. In that time, over 1.1 million pounds of yellowcake has come from alternate feed processed at the mill.

Dane Finerfrock, director of the Utah Division of Radiation Control, told the committee that the company's proposal meets the division's safety and health standards. The division last July granted a request by International Uranium to amend its operating license for the mill to accept the alternate feed.

The estimated 32,000 tons of feed material would come from an extinct "rare metal extraction" site in Oklahoma. That material is being called radioactive waste by the Glen Canyon Group of the Sierra Club and the group Healthy Environmental Alliance of Utah (HEAL).

Their concern is rooted in whether the company is properly licensed and able to safely store certain types of waste in its lined retention ponds near the mill.

"You just have a lot of unknowns that haven't been analyzed," said HEAL director Vanessa Pierce. Colorado, the only other state with a uranium-processing mill, no longer accepts alternate feed, she noted.

One unknown for the company's critics at the meeting was whether the ore or alternate feed that International Uranium has accepted in the past or proposes to accept now contains enough uranium for the company to economically justify the extraction process or if the material should simply be classified as waste, which could require a new definition of the White Mesa mill's role for state regulators.