The San Onofre nuclear power plant will test its community alert siren system today, officials said.
The siren will sound between 10 a.m. and noon. It is part of the facility's annual system test.
Residents of San Clemente, Dana Point, San Juan Capistrano, Camp Pendleton and unincorporated areas of south Orange County will hear sirens sound twice for up to five minutes at a time. Residents with concerns or questions should call San Onofre at (800) 332-3612.