 I'm Peter McArthur, WDEL News. Emergency officials will be testing the alert system of the Salem and Hope Creek nuclear power plants tonight. The email will set off the 37 sirens within 10 miles of the power plants, which includes Delaware City, Middletown, Odessa and Townsend. Residents hearing the siren are advised to tune to WDEL for a message in case of an emergency. The sirens tested four times a year.