July 8. On Wednesday, July 9, Duke Energy will conduct a routine test of the outdoor warning sirens surrounding the McGuire Nuclear Station in Huntersville, according to Duke Energy. 

The sirens will be tested between 11 am and 1 pm, and the testing is a routine part of maintenance to ensure the sirens are functioning properly. 

The sirens will sound for a duration of five to 30 seconds, and may be tested more than once. These tests are coordinated with local emergency management officials in Mecklenburg County.
 During the test, the sirens will be activated within a 10-mile radius of the McGuire Nuclear Station. The public does not need to do anything.

In the event of an actual emergency at the plant, local radio and television stations would broadcast information and instructions to the public.