A tractor-trailer hauling about 6,000 pounds (2,700 kilograms) of low-grade uranium overturned as it exited a major U.S. interstate highway, but the crash did not pose a threat to the public, authorities said.

The truck crashed onto its side after the driver lost control on an exit ramp along Interstate 95, said Jason Barbour, Johnston County's emergency communications director. One of two people in the truck suffered minor injuries, and no other vehicles were involved, he said.

The truck was carrying a radioactive material called packaged fissile, Highway Patrol spokesman Lt. Everett Clendenin said. The powdered uranium was packed in containers that weren't breached by the accident, he said.

"There's no threat to the public," Clendenin said. "It's a low grade uranium."

Traffic was diverted after the 9 p.m. crash south of Raleigh, and the exit ramp to Interstate 40 was closed for several hours. Clendenin said the ramp should reopen early Friday morning.

The uranium was being transported by Portsmouth Marine Terminal, from Portsmouth, Virginia, to Global Nuclear Fuels in Wilmington, a coastal city about 130 miles (209 kilometers) southeast of Raleigh.