SALT LAKE CITY - The Nuclear Regulatory Commission says classifying large amounts of depleted uranium as a more hazardous type of low-level radioactive waste without further study would not provide additional protections to public health, safety or the environment.

The NRC's comments come in an April 9 letter to Reps. Jim Matheson, D-Utah, and Edward Markey, D-Mass. The congressmen have questioned the NRC's March decision to regulate quantities of depleted uranium as the least hazardous kind of low-level radioactive waste, which could bring more than 1 million tons of depleted uranium to Utah and Texas for disposal.

Depleted uranium is different from other waste because it becomes more radioactive over time.