CHEYENNE, Wyo. (AP) — U.S. regulators and representatives of a Canadian uranium mining company will discuss what caused radioactive sludge to leak from a truck onto a highway on two occasions.

The Nuclear Regulatory Commission says Saskatoon, Canada-based Cameco broke rules including not hauling the sludge in proper containers. The meeting between NRC and Cameco officials happens Thursday at NRC offices in Arlington, Texas.

The slightly radioactive sludge came from a uranium processing facility in Wyoming where Cameco mines the nuclear fuel.

Cameco shipped the sludge from Wyoming through Colorado to a waste site near Blanding, Utah. In 2015 and again in 2016, truck containers leaked onto U.S. Highway 191 near the site.

Company officials say the spills were cleaned up and they aren't aware of any risk to the environment or people.