NRC Cites Welding Violation at MOX Facility

Some welding on the Savannah River Site’s Mixed Oxide Fuel Fabrication Facility (MFFF) may be redone following a violation detected during an inspection last month. The Nuclear Regulatory Commission noted that design documents for work at the MFFF included inadequate welding measurements based on standards established by the American Welding Society. The MFFF is the main facility for the nation’s MOX project, through which the U.S. intends to dispose of 34 metric tons of weapon-usable plutonium. The MOX project is expected to accomplish the feat, required under a bilateral accord with Russia, by converting the plutonium into commercial nuclear fuel.

 

The issue is associated with a minor design error that resulted in a limited number of welds to be slightly below code requirements. A ground and sorted pellet storage unit glove box and a number of shield panels at the MFFF were installed with quarter-inch welds. But the American Welding Society requires welding of safety-related steel that is thicker than three-quarters of an inch to have a minimum weld size of five-sixteenths of an inch. The discrepancy caused the NRC to cite a Level 4 violation, the lowest the agency can give. The NRC wrote that the violation "will result in the need to perform a code deviation or rework of the welds."

 

The NRC reported that CB&I AREVA MOX Services, the contractor leading construction of the MFFF, has already started making corrective actions and that the issue will be treated as a non-cited violation. The corrective actions are expected to be completed by the end of the year.