September 27, 2012
SODDY DAISY, Tenn. — The Tennessee Valley Authority will upgrade and replace its existing 108 emergency notification sirens within a 10-mile radius of the Sequoyah Nuclear Plant beginning in early October, and will also install four additional sirens to enhance siren sound coverage.
The new, state-of-the-art siren system contains backup battery power capability to ensure continuous siren operation for up to seven days.
Contractor crews will be replacing sirens at the rate of two to four units per day throughout the plant’s 10-mile Emergency Planning Zone. The crews will be working six days a week to finish the job by late December.
The new sirens run on conventional electrical service, but feature a battery backup designed to keep them operating for up to a week if power is interrupted.
“The recent tornadoes in Hamilton County are a reminder of the importance of the sirens to the safety of the community,” said Sequoyah Site Vice President John Carlin. “It is vital that we ensure the sirens are effectively operating each and every day.”
After installation, each siren will be tested to make sure it operates properly. This will result in individual sirens being sounded multiple times daily, six days a week, for the next two or more months, until all sirens are replaced. These soundings should last about 20 seconds.
The Sequoyah Nuclear Plant Emergency Planning Zone includes Hamilton and Bradley counties in Tennessee. Sirens will be replaced in both counties.
The replacement sirens will be mounted on steel, rather than wooden poles, to increase reliability during severe weather. The new sirens will sound the same as the old ones and will continue to be tested on the first Wednesday of each month at approximately noon.
Upon completion of the Sequoyah siren installation, TVA will then replace the sirens at Watts Bar Nuclear Plant in Spring City, Tenn. TVA has already completed new siren installation at Browns Ferry Nuclear Plant near Athens, Ala. TVA is investing about $7 million to replace all sirens.