Federal regulators cited the largest contractor at the Savannah River Site nuclear complex in Aiken, S.C. for failing to follow safety procedures.
Employees of Westinghouse Savannah River Co,. failed five times to follow procedures designed to prevent "criticalities," or chain reactions, in late November and early December, according to the Defense Nuclear Facilities Safety Board, which is responsible for nuclear weapons complex oversight.
The citation comes just two months after the U.S. Energy Department, which owns the complex, told Westinghouse to improve safety procedures there because of other incidents.
The latest problem occurred in a facility that recovers useful materials from radioactive and chemical wastes, and in a plant that stabilizes plutonium left over from other operations.