Officials at the nuclear plant in Wake County said there were no radioactive materials released because of the incident.
After an inspection of equipment revealed no threat to safety, officials terminated the alert. Around 6 a.m., plant personnel said they were operating at a reduced power level of 91 percent as recovery actions continued.
"The alert was terminated at 5:33 a.m. ... and it was an electrical fault on a transformer, like an electrical box similar to your breaker in your house, so it was running non-safety related equipment," Kim Crawford spokesperson with Duke Energy said. "[There was] a little bit of smoke, so we had to declare this alert. The plant is stable and online, no injuries, no danger ever to the public from this event."
Crawford also said the incident happened on the non-reactor side of the plant and was not related to the cracks and corrosion found in a reactor vessel that caused it to shut down in May.
No connection at all," she said. "This is on the secondary side of the plant. That was something we had to repair, that was a maintenance outage, but no relationship at all to that event.
According to Duke Energy, who jointly owns the plant with the North Carolina Eastern Municipal Power Agency, plant employees had staffed emergency response facilities during Thursday morning's event, and coordinated with federal, state and local officials to resolve the situation and protect the public.
The plant also had state/county emergency management officials on standby to activate sirens located throughout the plant's 10-mile emergency planning zone (EPZ) if needed. Sirens alert residents to listen to local radio and television stations for information and instructions.
Emergency preparedness information is also available at duke-energy.com, just search for "emergency preparedness."
An alert is the second in increasing significance of four nuclear emergency classifications and is used to describe conditions that require emergency response agencies to be in a heightened state of readiness, but pose no threat to public safety.
The Shearon Harris Nuclear Plant is a single-unit power plant located on Harris Lake, near New Hill, North Carolina -- about 20 miles southwest of Raleigh.