People living near TVA's Watts Bar Nuclear Plant now have a new alert system.
Friday, crews installed and tested a new warning siren system.
There are 100 sirens around the 10-mile emergency zone.
You can hear them from up to 3000 feet away from the plant.
TVA says the new sirens are an improvement from the old system.
"They're more efficient, more effective. They're on steel poles rather than wood poles. They're more sturdy," said Program Manager Al Saltka.
One upgrade, an electric motor operates the sirens rather than compressed air.
The new system should last for the next 35 years.
This replacement is part of a $7-million dollar program to upgrade the warning sirens at TVA's three nuclear plants.