After two tests of the newly-upgraded sirens in the in the 10-mile emergency planning zone around the Oyster Creek Nuclear Power Plant in Lacey, the originals get a run-through on June 4.

Oyster Creek sirens (Jason Allentoff, Townsquare Media NJ)

The 42 signals are the primary notification of an emergency at the generating station for thousands of people who live, work or attend school in the vicinity.

Exelon, the plant's parent company, recently upgraded the system to create a louder warning, equipping each for the first time with battery backup capabilities. The sirens must undergo review and approval by the Federal Emergency Management Agency.

The original sirens sound off for three minutes at 10 AM this Tuesday.