Browns Ferry Sirens Impacted By Storm-Related Power Outages
August 5, 2011
On early Thursday morning (8/4), strong thunderstorms in Northern Alabama caused loss of power to 35 of the 100 Browns Ferry Emergency Alert and Notification System Sirens. Browns Ferry immediately began contacting state and local emergency planning officials, as well as the on-site NRC resident inspector of the loss of sirens.
By approximately 10:00 a.m. CDT, power was restored to 14 of the de-energized sirens, resulting in 21 out of 100 remaining out of service. At 3 p.m. CDT, the number of sirens remaining de-energized had been reduced to seven. As of 9:30 a.m. CDT, on Friday (8/5), the number of sirens out of service is down to three. TVA, and the local power utility, are working to restore power to the remaining three.
The event was reported to the Nuclear Regulatory Commission as required by regulations. The event was also reported to state and county officials. The sirens, which are part of the State of Alabama’s emergency plan, are maintained by TVA. When sirens are unavailable, state and county emergency officials have contingency plans for alerting residents during an emergency. This involves “route alerting,” the use of emergency vehicles driven along pre-determined routes to make emergency announcements via loudspeaker. TVA’s Emergency Preparedness group in Chattanooga performs regular silent tests, growl tests and full cycle tests to ensure sirens operability.