San Onofre nuclear reactors remain in 'safe shutdown'
The two nuclear reactors at San Onofre nuclear power plant remain in "safe shutdown" as operators continue to review events with a view to restoring the units, said Gil Alexander, spokesman for Southern California Edison.
Officials on Thursday said the power outage did not cause any safety issues at the plant, but said a fluctuation in power caused the reactors to shutdown at 3:38 p.m.
He said the system worked as it was supposed to during a loss of power.
In all, about 4 million customers lost power Thursday afternoon in San Diego and Orange counties, the Inland Empire and parts of Mexico in an unprecedented outage.
The blackout was triggered by a mishap on a high-voltage power line linking Arizona and San Diego, causing a cascading series of electrical grid failures stretching into Southern California.
-- Richard Winton