TVA is to begin today replacing 100 emergency sirens within the Watts Bar Nuclear Plant's 10-mile radius in McMinn, Meigs and Rhea counties.
The work follows similar replacements at Browns Ferry Nuclear Plant near Athens, Ala., last spring as well as replacements around Sequoyah Nuclear Plant in Soddy-Daisy in November and December.
The new state-of-the-art sirens have back-up battery power and steel poles. The cost to replace them around all three nuclear plants tallies about $7 million.
Tim Cleary, the Watts Bar site vice president, said recent tornadoes and powerful storms in the Tennessee Valley point up the importance of the sirens.
"It is vital that we ensure the sirens are effectively operating each and every day," Cleary said in a prepared statement.
Tennessee Valley Authority spokesman Ray Golden said contractor crews will be replacing the old sirens at the rate of two to four units per day. The crews will work six days a week to finish the job, he said.
After installation, each siren will be tested to make sure it operates properly. This will result in individual sirens being sounded several times daily, six days a week, for the next two or more months.
Golden said the test soundings should last only about 20 seconds. An actual activation of the warning siren would last about three minutes.
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 about noon.