San Onofre Nuclear Plant Accident – Updated Information

Update: Via twitter – @SanDiegoCounty: San Onofre officials: the leaked ammonia has been contained they are now ventilating the building.

There was an accident at the San Onofre nuclear power plant in California. The plant is in the NW corner of San Diego county on the ocean front. Reports state that ammonia at the plant used to purify the steam system leaked at the unit 3 turbine building. The plant is telling officials that it is on the “non-nuclear” side of the systems and that the reactor is still running.  The reactor in question is a Combustion Engineering PWR.

“The County of San Diego, in response to the alert, has activated and staffed the Operational Area Emergency Operations Center with county agency representatives, in order that it may be prepared should the situation at the power plant deteriorate. All resources and support personnel have been identified and are on standby, ready to be mobilized, if needed.” link

NBC Los Angeles calls it an “Alert”
LA Times has called it both a “Level 3 Emergency” and a “Level 2 Emergency”
San Diego County EMS is calling it an “Alert”
Huffington Post is calling it a “Level 3 Alert” * rereading it the post with no author declares it an INES 3 – if you read what it is below they are way off base.

No outlet or official has clarified what emergency scale they are using. There is an INES scale and also the NRC alert level scale.

Unusual Event 
This is the lowest of the four emergency classifications. This classification indicates that a small problem has occurred. No radiation leak is expected and federal, state and county officials are notified.

NRC Alerts
Events are in process or have occurred which involve an actual or potential substantial degradation of the level of safety of the plant. Any releases expected to be limited to small fractions of the EPA Protective Action Guideline exposure level

NRC Site Area Emergencies
Events are in process or have occurred which involve actual or likely major failures of plant functions needed for protection of the public. Any releases not expected to exceed EPA Protective Action Guideline exposure levels except near site boundary.

NRC General Emergencies
Events are in process or have occurred which involve actual or imminent substantial core degradation or melting with potential for loss of containment integrity. Releases can be reasonably expected to exceed EPA Protective Action Guideline exposure levels offsite for more than the immediate site area.

Below is the INES scale that is a number system of 1-7. Just levels 2 and 3 are posted since those relate to some of the vague media claims.
Level 3: Serious incident
Impact on people and environment
Exposure in excess of ten times the statutory annual limit for workers.
Non-lethal deterministic health effect (e.g., burns) from radiation.
Impact on radiological barriers and control
Exposure rates of more than 1 Sv/h in an operating area.
Severe contamination in an area not expected by design, with a low probability of ­significant public exposure.
Impact on defence-in-depth
Near accident at a nuclear power plant with no safety provisions remaining.
Lost or stolen highly radioactive sealed source.
Misdelivered highly radioactive sealed source without adequate procedures in place to handle it.
THORP plant Sellafield (United Kingdom) – 2005.
Paks Nuclear Power Plant (Hungary), 2003; fuel rod damage in cleaning tank.
Vandellos Nuclear Power Plant (Spain), 1989; fire destroyed many control systems; the reactor was shut down.
San Onofre Nuclear Generating Station (United States), 2011; Ammonia leak. No evacuation called for.
Level 2: Incident
Impact on people and environment
Exposure of a member of the public in excess of 10 mSv.
Exposure of a worker in excess of the statutory annual limits.
Impact on radiological barriers and control
Radiation levels in an operating area of more than 50 mSv/h.
Significant contamination within the facility into an area not expected by design.
Impact on defence-in-depth
Significant failures in safety ­provisions but with no actual ­consequences.
Found highly radioactive sealed orphan source, device or transport package with safety provisions intact.
Inadequate packaging of a highly radioactive sealed source.
Blayais Nuclear Power Plant flood (France) December 1999
Ascó Nuclear Power Plant (Spain) April 2008; radioactive contamination.
Forsmark Nuclear Power Plant (Sweden) July 2006; backup generator failure.

What we currently know looks like possibly a NRC Alert, NRC Alerts DO NOT HAVE NUMBERS attached to them. The INES number scale of 2 or 3 does not fit with what is currently being told to the public.

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