Update: County Officials Cancel Emergency Alert at Nuclear Station

Updated at 7 p.m. Tuesday.

County officials have canceled an emergency alert that prompted the evacuation of employees after an ammonia leak in a water-treatment system at the San Onofre Nuclear Generating Station mid-Tuesday afternoon.

There is "no radioactive material" involved in the leak, county officials said in a statement.

"As a precaution, the company evacuated employees in the area near where the leak was found,'' according to a statement from Southern California Edison, the majority owner of the plant. "Other employees remain in other areas of the plant. There's no immediate danger to the public. Those units are operating normally.''

The ammonia leak, which was discovered around 3 p.m. in a non-nuclear part of the plant, prompted an alert because the fumes could have prevented access to the plant, according to Edison. Previously, officials had said the leak was in the steam system used to drive the station's turbines.

"The control room is staffed and fully operational and the plant is under 100 percent power,'' according to Edison.

Here is the statement from the San Diego County Operational Area Emergency Operations Center:

At  2:50 p.m. today, the San Onofre Nuclear Generating Station notified the County of San Diego of an ALERT at the station. The plant reports that the ALERT is related to the release of a gas at the plant and that current conditions do not threaten public safety. The County of San Diego, in response to this Alert, has activated and staffed the Operational Area Emergency Operations Center (EOC) with County agency representatives, in order that it may be prepared should the situation at the power plant deteriorate.

At this time, there is no recommended action for the public. We will continue to monitor the situation very closely and advise the public of any changes. The Public Information Hotline has been staffed and is ready to accept questions regarding the current events at the San Onofre Nuclear Power Plant. The Emergency Operations Center has asked that all persons requesting additional information regarding the San Onofre Nuclear Generating Station emergency contact the Public Information Hotline at 2-1-1. Unless there is a life-threatening emergency, do not call 9-1-1.

All resources and support personnel have been identified and are on standby, ready to be mobilized, if needed.

City News Service contributed to this report.