Utah Gov. Gary Herbert is sending Energy Secretary Steven Chu a letter asking him to halt the shipment of nearly 15,000 drums of low-level radioactive waste from South Carolina for disposal in Utah.

Herbert says the Department of Energy is circumventing state regulators' efforts to ensure a private disposal facility in Utah's west desert can safely dispose of the depleted uranium.

Depleted uranium is different from other waste EnergySolutions Inc. disposes of at its site because it becomes more radioactive over time for up to a million years.

State regulators and the Nuclear Regulatory Commission have acknowledged that difference and have started a rule-making process to address whether it may need to be disposed of differently.