Chemical Safety Incidents
Nuke Relief Valves Force Inspection
Friday, April 8, 2016 @ 04:04 PM gHale
A special inspection of safety relief valves will start up for Unit One of the Hatch nuclear plant operated by Southern Nuclear Operating Co.
After the Baxley, GA-based unit’s last refueling outage, plant officials sent all 11 of the safety relief valves, which provide protection from excessive steam pressures and had been replaced during the outage with the same type of valve, to a laboratory for testing.
During test procedures, three of the valves did not perform as expected. The cause of the three valves failing to close during the tests has not yet been determined.
Even though the valves were in service during the unit’s last operating cycle, none failed during reactor operations and there was no danger to the public.
“These valves provide an important safety function and it is essential that we understand why they failed to perform as expected during these tests,” said Cathy Haney, Nuclear Regulatory Commission (NRC) Region II administrator. “We felt a special inspection was warranted to gather more information about these valves.”
The onsite inspection will be led by the senior resident inspector at Hatch. He will end up assisted by the second Hatch resident inspector and two inspectors from NRC headquarters in Rockville, MD, both with valve expertise. A senior risk analyst from Region II in Atlanta will also contribute to the effort. The five-member team will identify the circumstances of the test failures, review Southern Nuclear’s actions following discovery of the failures, review the testing methodologies, assess Hatch’s maintenance practices, evaluate the operating history of the valves and assess the licensee’s conclusions of the operability of the valves in service.
The onsite portion of the inspection will take several days. A report documenting the results of the inspection should end up issued within 45 days of the completion of the inspection.