The worker, who continues to undergo evaluation to determine the extent of his exposure, sustained a small wound that penetrated six layers of protective clothing and gloves before piercing his finger.
He was working in the site's F-Area, where waste was being packed for shipment to New Mexico.
Jim Giusti, an Energy Department spokesman at the site, said the DOE inquiry will supplement an existing investigation by the site's contractor, Savannah River Nuclear Solutions.
The newest inquiry will be led by Jeffrey Allison, the director of DOE-Savannah River's Office of Special Projects, and is expected to be completed late this month.
Work remains halted in the processing line where the worker was injured, Giusti said.