The siren test remains a regulatory requirement even though the plant is retired, according to Pete Dietrich, senior vice president and chief nuclear officer at Rosemead-based Southern California Edison.
In a real emergency, the siren system would alert residents to turn on their radio or television for emergency response information from public officials.
Fifty sirens will sound several times in the communities around the San Onofre nuclear plant from 10 a.m. to noon Oct. 16 and will last about three minutes each time. The sirens sound a continuous, steady tone, making them noticeably different from those used by fire and police departments.
Fliers explaining the test have been distributed to residents, businesses and schools in the area. Before and during the siren test, broadcasts on Orange County's primary Emergency Alert System radio station, KWVE 107.9, will inform the public of the test.
The sirens are activated by Orange County, the cities of Dana Point, San Clemente and San Juan Capistrano, state parks officials and Camp Pendleton.
The sirens also could be used by local government officials to inform residents of a non-nuclear emergency.
SCE announced June 7 that it would retire San Onofre Units 2 and 3, and begin the process to decommission the facility, which is jointly owned by SCE (78.21 percent), San Diego Gas & Electric (20 percent) and the city of Riverside (1.79 percent).
