United States Nuclear Regulatory Commission - Protecting People and the Environment

Emergency Classification

The NRC has established Emergency Classifications that group events or conditions according to (1) potential or actual effects or consequences, and (2) resulting onsite and offsite response actions. The emergency classifications increase in severity from Notification of Unusual Event (NOUE); Alert; Site Area Emergency (SAE); and General Emergency (GE). Both nuclear power plants and research and test reactors use these terms as defined below. The vast majority of events reported to the NRC are routine in nature and are handled outside of our incident response program. Our response to an event that could affect public health and safety is discussed in How We Respond To an Emergency.

  • Notification of Unusual Event (NOUE) – A situation is in progress or already completed which could potentially degrade the plant's level of safety or indicate a security threat to the facility. No releases of radioactive material requiring offsite actions are expected unless safety systems degrade further. [Note: The terms Notification of Unusual Event, NOUE and Unusual Event are used interchangeably.]

    Purpose: This classification ensures the first steps for future response are being carried out, that operations staff are at the ready, and that the plant systematically handles unusual event information and decision-making.

  • Alert – Events are in progress or have occurred which have (or could) substantially degrade the plant safety; or, a security event that could threaten site personnel or damage to site equipment is in progress. Any offsite releases of radioactive material that could occur are expected to be minimal and far below limits established by the Environmental Protection Agency's (EPA) protective action guides (PAGs).

    Purpose: This classification ensures that emergency personnel are ready and available to respond if the situation becomes more serious or to perform confirmatory radiation monitoring if required, and also ensures that offsite authorities receive current information on plant status.

  • Site Area Emergency (SAE) – Events are in progress or have occurred which have caused (or likely will cause) major failures of plant functions that protect the public, or involve security events with intentional damage or malicious acts that could lead to the likely failure of (or prevent effective access to) equipment needed to protect the public. Any offsite releases of radioactive material are expected to remain below EPA PAG exposure levels beyond the site boundary.

  • Purpose: A SAE declaration ensures: a) emergency response centers are staffed; b) monitoring teams are dispatched; c) personnel required for evacuating nearby areas are at duty stations if the situation becomes more serious; d) proper consultation with offsite authorities; and e) government authorities are providing updates to the public.

  • General Emergency – Events are in progress or have occurred which: a) have caused (or shortly will cause) substantial reactor core damage, with the potential for uncontrolled releases of radioactive material; or, b) involve security events that deny plant staff physical control of the facility. Offsite releases can be reasonably expected to exceed EPA PAG exposure levels beyond the plant site.

  • Purpose: A GE declaration initiates predetermined protective actions for the public including: a) continuous dose monitoring by the licensee and offsite organizations; b) additional protective measures as necessitated by potential or actual releases; c) consultation with offsite authorities; and, d) updates to the public by government authorities.

Nuclear materials and fuel cycle facility licensees have two emergency classifications:

  • Alert - Events may occur, are in progress, or have occurred that could lead to a release of radioactive material[s], but below the level requiring an offsite response to protect the public.

  • Site Area Emergency - Events may occur, are in progress, or have occurred that could lead to a significant release of radioactive material[s] requiring an offsite response to protect the public.

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Page Last Reviewed/Updated Thursday, October 29, 2020