An Emergency Classification is a set of plant conditions which indicate a level of risk to the public. Both nuclear power plants and research and test reactors use the four emergency classifications listed below in order of increasing severity. The vast majority of events reported to the NRC are routine in nature and do not require activation of our incident response program. For information on how we respond to an event that could threaten public health and safety, see How We Respond To an Emergency.
Recognizing that security-related events may involve different response actions from the licensees, the NRC issued Bulletin 2005-02, Emergency Preparedness and Response Actions for Security-Based Events. This bulletin identifies minor changes to the emergency classification levels to reflect emphasis of post-9/11 conditions.
- 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.
- Alert - 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) .
- 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.
- 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 following are emergency classifications for nuclear materials and fuel cycle facility licensees:
- Alert - Events may occur, are in progress, or have occurred that could lead to a release of radioactive material[s], but the release is not expected to require a response by an offsite response organization to protect people offsite.
- Site Area Emergency - Events may occur, are in progress, or have occurred that could lead to a significant release of radioactive material[s], and the release could require a response by offsite response organizations to protect people offsite.