Fluid was leaking about one gallon every 10 minutes. The leak was reportedly contained by 5:30 p.m. The alert was declared over by 6 p.m.
As a protective action due to the leak, personnel in the turbine building for Unit 3 were asked to leave as the alert was issued.
No one was evacuated and there were no injuries.
There was no threat outside the power plant.
The alert prompted the Orange County Emergency Operations Center to activate a public information hotline.
The Public Information Hotline phone number is (714) 628-7085. The information line was to stay open until 9 p.m. PT.
The OC Emergency Operations Center stated the public is not at risk and no protective actions were necessary.
The Orange County Operational Area Emergency Operations Center released a statement at 5:30 p.m.: "The event is considered a low level, 'non nuclear' emergency and the ammonia leak is contained."
The public can check http://songscommunity.com/ for additional information as it becomes available.
The alert at San Onofre Nuclear Generating Station was closed by 6 p.m., according to the Emergency Operations Center.
The station is located approximately 60 miles north of San Diego; about 5 miles south of San Clemente.