One lesson learned from the region's tornadoes over the past year is resulting in a sirens upgrade for all three TVA nuclear plants, beginning with Browns Ferry near Athens, Ala.
"The severe weather in this area over the last year is a reminder of the importance of the sirens to the safety of the community," said Browns Ferry site Vice President Keith Polson in a prepared statement.
The new sirens run on conventional electrical service, but feature a battery backup designed to keep them operating for up to seven days if power is interrupted, as it was for several days after last April's tornadoes.
The Tennessee Valley Authority is replacing all 100 emergency sirens with units equipped with battery backups in a 10-mile radius of Browns Ferry.
When the Browns Ferry project is finished in late spring, TVA will replace the sirens around Sequoyah in Soddy-Daisy and around Watts Bar near Spring City, Tenn.
The sirens' tally for all three plants is about $7 million, TVA said.
At Browns Ferry, contractor crews will replace sirens at the rate of four to six a day and be working six days a week in Lauderdale, Limestone, Lawrence and Morgan counties of North Alabama, the release said.
Each replaced siren will be tested to make sure it operates properly. The testing will result in sirens being sounded multiple times a day, six days a week, until all sirens are replaced. When all sirens are installed, a full sounding of all sirens is likely, said TVA spokesman Ray Golden.
The replacement sirens also will be mounted on new steel poles, rather than the wooden poles used with the old sirens.