The Nuclear Regulatory Commission is considering escalated enforcement for an apparent violation at the Oconee nuclear plant involving a weld inspection procedure the agency said was inadequate to prevent a leak in a safety system.
In November, unit 1 at the South Carolina plant shut down after a small leak in a high pressure injection system. It was repaired and caused no immediate danger to the reactor or the public. Nonetheless, the NRC is considering a greater-than-green regulatory finding because plant operator Duke Energy did not discover a cracked weld earlier.
"In 2004, a procedure was developed for augmented in-service inspection program ultrasonic examinations, which effectively removed reasonable assurance that HPI nozzle component weld cracking would be identified and corrected," the NRC wrote in a letter to the utility.
After the leak, the NRC reported, a review of 2011 radiographic film revealed indications of a crack extending about 50 percent through the weld. The agency has scheduled a regulatory conference with Duke July 31 to discuss the apparent violation before making an enforcement decision.