Nuclear Power Plant Incidents – Warning Alert Notifications

Cooper Nuclear Station near
Brownsville, NE[2]

Although the construction and operation of nuclear power plants are closely monitored and regulated by the Nuclear Regulatory Commission (NRC), accidents are possible and severe accidents are very rare. A nuclear plant emergency could result in dangerous levels of radiation that could affect the health and safety of the public living near the nuclear power plant.

A nuclear radiation accident is defined by the International Atomic Energy Agency (IAEA) as “an event that has led to significant consequences to people, the environment or the facility.” Examples include lethal effects to individuals, large radioactivity release to the environment, or reactor core melt.[1]

Emergency Classification Notifications

An Emergency Classification is a set of plant conditions which indicate a level of risk to the public. The vast majority of events reported to the NRC are routine in nature and do not require activation of our incident response program.[3]

In order to know the operating state of a nuclear power plant, you should familiarize yourself with warning notifications of the four emergency classifications listed below in order of increasing severity:

Notification of Unusual Event
Under this category, events are in process or have occurred which indicate potential degradation in the level of safety of the plant. No release of radioactive material requiring offsite response or monitoring is expected unless further degradation occurs.

No action on your part will be necessary.

If an alert is declared, events are in process or have occurred which involve an actual or potential substantial degradation in the level of safety of the plant. Any releases of radioactive material from the plant are expected to be limited to a small fraction of the Environmental Protection Agency (EPA) protective action guides (PAGs).

This will not affect you and no action is required.

Site Area Emergency
A site area emergency involves events in process or which have occurred that result in actual or likely major failures of plant functions needed for protection of the public. Any releases of radioactive material are not expected to exceed the EPA PAGs except near the site boundary.

Area sirens may be sounded.

Listen to your radio or television for safety information.

General Emergency
A general emergency involves actual or imminent substantial core damage or melting of reactor fuel with the potential for loss of containment integrity. Radioactive releases during a general emergency can reasonably be expected to exceed the EPA PAGs for more than the immediate site area.

The sirens will sound.

Tune to your local radio or television station for reports. Be prepared to follow instructions promptly.



  1. International Atomic Energy Agency:
  2. Image Source: [Accessed July 24, 2013]
  3. United States Nuclear Regulatory Commission (U.S.NRC):