Exelon Generation will conduct up to six separate emergency warning siren tests beginning around 8 a.m. Thursday, Nov. 15. Each test will last about three minutes.

Exelon Generation has installed a new state-of-the-art siren system around Three Mile Island, part of a $13 million investment to upgrade sirens around all of the company's nuclear stations.

The system is now undergoing extensive testing in accordance with Federal Emergency Management Agency requirements for new siren systems.

A postcard announcing the test schedule was mailed to all residents who reside within the TMI Emergency Planning Zone.