The NRC said recent engineering inspection found degradation in the paint inside the torus, a donut-shaped component of the reactor containment located below the reactor vessel.
The torus is filled with water designed to absorb energy from the reactor or to be supplied to safety systems during an accident.
Loose paint chips from the torus could potentially impede the flow of water to safety-related equipment, the NRC said.
The NRC said a five-member team will work to establish the sequence of events related to the degradation of the paint, review the plant’s maintenance practices, and assess the overall response since the discovery of the condition.
The team will provide their preliminary conclusions regarding the significance of the issue in a publicly available report to be released approximately 45 days following completion of the inspection.
Fermi-2 is a 1,093-MW boiling water reactor unit and began commercial operation in January 1988.
The NRC said the plant will remain operational during the special inspection process.