The sirens in the 10-mile Emergency Planning Zone (EPZ) around the plant serve as an outdoor warning system in the event of an emergency. If an emergency at the plant required the sirens to be sounded, sirens would sound repeatedly. If you hear a loud, steady sound coming from one of the sirens around the nuclear plant, tune to a local radio or TV station for more information.
Hearing a siren does not mean you should evacuate. Local radio and television stations would be the primary means of providing information and instructions to the public. Sirens would be sounded, but they would not necessarily be heard inside homes or businesses.