Three Mile Island Generating Station

Emergency siren test scheduled for December 5

Exelon Generation will conduct its semi-annual, full volume test of the emergency warning sirens surrounding Three Mile Island (TMI) Generating Station on Thursday, December 5 at approximately 12:15 p.m.  Sirens to sound for three minutes at 12:15 p.m.  This is one of two semi-annual tests performed each year.

The emergency warning siren system consists of 96 sirens located in parts of Cumberland, Dauphin, Lancaster, Lebanon and York counties within a 10-mile radius of TMI. The sirens are not a signal to evacuate, but a warning to tune to a local emergency alert broadcast television or radio station. County emergency management authorities activate the sirens, which can be used in the event of any emergency, including severe weather. 

Although TMI Unit 1 permanently shut down on September 20, 2019, the siren system must remain in operation in accordance with local, state and federal emergency planning requirements until certain emergency procedures and processes are no longer in place. Those procedures are expected to be discontinued in accordance with federal regulator oversight.