The Nuclear Regulatory Commission last week formally notified power provider Exelon that it was increasing oversight of its Oyster Creek Nuclear Generating Station in New Jersey after the federal agency identified a safety violation during a Jan. 4 test.
The “white” — low to moderate safety significance — determination was reported to Exelon Generation Senior Vice President Bryan Hanson on July 7, according to documents released late on July 8. Specifically, a 3-inch hose used for cooling one of the facility’s two emergency diesel generators was found to have failed, and to have been out of operation for more than the allowed seven days.
This led to Oyster Creek being dropped from Column 1 (Licensee Response) to Column 2 (Regulatory Response) in the NRC Action Matrix. Plants that fall to Column 5 would be in danger of license suspension or revocation.
Exelon did not contest the finding, and indicated on July 8 it has already resolved the problem.
“Earlier this year, technicians identified and repaired a defective coolant hose on one of two Emergency Diesel Generators at Oyster Creek. The issue did not result in any elevated risk to the plant but it did result in an NRC violation,” spokeswoman Suzanne D’Ambrosio said by email. “We look forward to demonstrating to the NRC that our corrective actions were appropriate to ensure safety and prevent reoccurrence.”
The flexible coupling hose in question had been in use for about 22 years, and had sustained “thermal degradation” as it aged, according to the letter from NRC Region 1 Administrator Daniel Dorman.
The generators are used to ensure crucial facility safety systems remain operational even if Oyster Creek loses power from the electrical grid, NRC spokesman Neil Sheehan said. The agency also determined that Exelon did not have adequate work instructions for swapping out the hoses every 12 years as cited in the company’s procedures and vendor information, Sheehan added by email.
The facility will now be placed under additional NRC monitoring, primarily via an inspection that will assess Exelon’s evaluation of the root cause of the failure, measures taken to resolve the problem, and whether it is indicative of performance issues in other areas of the site, Sheehan said by email. “Should the plant not successfully pass that inspection, the finding will remain open and a second inspection will be carried out.”
The inspection had not been scheduled as of Friday. Oyster Creek is due to close by the end of 2019.
