The Nuclear Regulatory Commission is expected to downgrade the Oyster Creek Nuclear Generating Station’s safety rating for the second year in a row, following another inspection violation at the New Jersey plant, which is owned by Exelon Corp.
NRC’s “white” finding, which signifies a low to moderate safety issue, stems from a Jan. 4 failure of a 3-inch hose that feeds water from a storage tank to a pump that supplies one of the plant’s emergency diesel generators.
NRC spokesman Neil Sheehan said Wednesday that because Exelon has decided not to challenge the finding, the plant will move from Column 1 to Column 2 of NRC’s Action Matrix for the second year in a row, meaning increased NRC oversight at the facility. Column 4 is the lowest rating a plant can have while remaining in operation.
Once the white finding is finalized at the Lacey Township, N.J. plant, NRC will wait until Exelon is ready for a supplemental inspection, in which NRC will analyze the underlying issue, determine the root cause, explore the operation as a whole, and examine what adjustments the company has made, so it doesn’t happen again. Sheehan said there is no timeline for when finalization and the subsequent inspection might occur.
“Earlier this year, technicians identified and repaired a defective coolant hose on one of the generators,” Exelon spokeswoman Suzanne D’Ambrosio wrote in an email Wednesday. “The issue did not result in any elevated risk to the plant but it did result in an NRC violation. We notified local stakeholders as a courtesy and look forward to demonstrating to the NRC that our corrective actions were appropriate to ensure safety and prevent reoccurrence.”
NRC in 2015 found two inspection violations, one “white” and one “yellow.” Like the most recent finding, the white finding stemmed from issues related to an emergency diesel generator at the plant. According to NRC documents, degradation to the generator’s cooling fan drive shaft, which keeps the generator from overheating, threatened backup power sources.
The yellow finding, which signifies “substantial safety significance,” concerned design aspects of the plant’s electromatic relief valves, which are used to depressurize the reactor during a pipe break, allowing coolant injection into the reactor core. This keeps nuclear fuel in the reactor covered and cooled as the shutdown progresses. The company discovered alignment issues with the valve’s actuator during refurbishment work in June 2014, according to NRC materials. Exelon has since addressed both issues.
At the time, NRC determined that the “yellow” finding stemmed from an old design issue, and “does not reflect a current performance deficiency associated with existing programs, policies or procedures used by the company.”
NRC on Thursday held a public meeting in Stafford Township, N.J., where officials provided information on the plant’s annual safety assessment.
