All Clear at Savannah River Nuclear Site in South Carolina

A South Carolina nuclear site was locked down for a few hours after a bomb dog alerted on a delivery truck, but no threat was found.

The plant, an Energy Department nuclear reservation that houses Savannah River National Laboratory, said in a brief statement that a subsequent investigation found no threat. The site reopened early Monday evening.

Sources at the plant told NBC station WAGT of Aiken that the truck was restocking vending machines around H Area, where the U.S.'s only hardened chemical separations facility operates.