The Tennessee Valley Authority declared an Unusual Event at Sequoyah Nuclear Plant on Wednesday evening when a fire involving a 500,000 volt transformer in a switchyard at the plant lasted more than 15 minutes before being extinguished.
The fire began shortly after 9:30 p.m. and was extinguished about 20 minutes later. At the time of the fire, the transformer was being placed in service following maintenance. The investigation into the cause of the fire began Wednesday night. The Unusual Event was terminated at 10:48 p.m. No injuries were reported.
An Unusual Event is lowest of the four levels of nuclear plant emergency classifications established by the Nuclear Regulatory Commission. In order from least serious, the classifications are: Unusual Event, Alert, Site Area Emergency and General Emergency. An Unusual Event poses no threat to the public or to plant employees. Appropriate federal, state and local emergency management agencies have been notified of the event.
Sequoyah Nuclear Plant is located on the Tennessee River near Soddy-Daisy, Tennessee, about 18 miles northeast of Chattanooga. The plant consists of two pressurized water reactors rated at about 2,300 megawatts.
At the time the event was declared, unit 1 was operating at about 85 percent power and unit 2 was at 100 percent power. Both units continue to operate safely at these power levels.