Hostile Action Based Emergency Preparedness (EP) Drills

A Hostile Action is an act toward a Nuclear Power Plant or its personnel that includes the use of violent force to destroy equipment, take hostages, and/or intimidate the licensee to achieve an end.

After September 11, 2001, the NRC required nuclear power plant licensees to make enhancements in several areas of emergency preparedness, including:

  • Alternate emergency response facilities
  • Emergency response organization staffing
  • Security-based Emergency Classification Levels and Emergency Action Levels
  • Onsite Personnel Protective Actions

These new measures were promptly put in place, and verified by the NRC through inspections. The NRC also formally reviewed the emergency preparedness planning basis to ensure that it will adequately protect the health and safety of the public in light of the current threat environment. The evaluation found emergency preparedness at nuclear power plants remains strong, but could be improved in a few areas, such as communications, resource management, drill programs, and NRC guidance. Based on this, the NRC began drafting new requirements for emergency preparedness and response in the event of hostile action against the facility.
In 2011, the NRC amended its emergency preparedness regulations to enhance preparedness and response to hostile action. Licensees are required to protect onsite personnel and to ensure the continued ability to safely shut down the reactor and implement emergency plans during hostile action. Emergency plans provide capabilities to declare hostile action events; identify the State, local, and Federal agencies expected to provide support during hostile action; and identify an alternative facility that would be accessible even if the site is under threat or experiencing hostile action to function as a staging area for augmentation of the emergency response organization (ERO) and to minimize delays in response.
A basic EP principle is that licensees conduct drills and exercises to develop and maintain key skill of the ERO. Licensees are required to conduct a full-scale exercise involving Federal, State, and local agencies at least once every two years as part of an eight year exercise cycle. Even though the radiological consequences will be the same whether caused by a hostile action or a plant event, hostile actions provide unique challenges for emergency responders. During each exercise cycle, challenging drills and exercises are performed to provide the ERO and offsite response organizations with opportunities to demonstrate the coordination necessary to respond to hostile action. NRC and FEMA evaluate these exercises in order to ensure the skills of emergency responders are maintained and to identify and correct any weaknesses. NRC assesses the onsite response, while FEMA assesses the offsite response. In the interim years, licensees conduct unevaluated drills and implement lessons learned from previous drills.
The NRC compiled significant lessons-learned from the first round of Hostile Action-Based (HAB) EP Exercises. These lessons learned are available to NPP licensees and Federal, State, and local emergency response professionals in the NRC’s Agencywide Documents Access and Management System (ADAMS) under Accession No. ML16207A435. In addition, lessons-learned from HAB EP Drills conducted, are available via the Department of Homeland Security (DHS) Lessons-Learned Information Sharing ( website. is the national network of Lessons Learned and Best Practices for emergency responders. is a secure, restricted-access information database, that is designed to facilitate efforts to prevent, prepare for, and respond to acts of terrorism and other incidents across all disciplines and communities throughout the US.

Additional details of HAB EP Drills can be found in the following documents:


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Date Description
07/25/2016  Report on Hostile Action-Based (HAB) Emergency Preparedness Biennial Exercise Lessons Learned
Interim Staff Guidance, NSIR/DPR-ISG-01, “Emergency Planning for Nuclear Power Plants”
04/2010 Revision 2 to NEI 06-04, “Conducting a Hostile Action-Based Emergency Response Drill”
03/19/2008 NRC Regulatory Issue Summary 2008-08, Endorsement of Revision 1 to Nuclear Energy Institute Guidance Document NEI 06-04, "Conducting a Hostile Action-based Emergency Response Drill"
11/09/2007 Public Meeting on the Status of Security-Threat Based EP
11/7-11/8/2007 NEI Workshop Presentations
10/30/2007 Revision 1 to NEI 06-04, "Conducting a Hostile Action-Based Emergency Response Drill"
05/18/2007 Supplement to NEI 06-04
08/06/2006 Revision 0 to NEI 06-04, "Guideline for the Development of Emergency Preparedness Drill and Exercise Threat-Based Scenarios"
07/19/2006 NRC Regulatory Issue Summary 2006-12, Endorsement of Nuclear Energy Institute Guidance "Enhancements To Emergency Preparedness Programs For Hostile Action"
11/18/2005 Industry White Paper, entitled "Enhancements To Emergency Preparedness Programs For Hostile Action" (Revised November 18, 2005)
07/18/2005 NRC Bulletin 2005-02: Emergency Preparedness and Response Actions for Security-Based Events

Since HAB EP Drills are currently being conducted as an Industry initiative, the NRC's role is that of an observer. In this role the NRC works with NEI to ensure consistent application of Revision 1 to NEI 06-04 and assists NRC staff in informing proposed rulemaking leading to the formal incorporation of HAB scenarios into the existing EP biennial exercise cycle. HAB EP Drills also provide opportunities to train NRC personnel on the unique challenges posed by security events and allow for NRC incident response personnel participation in these drills.

If you would like to provide input or comments about HAB EP Drills, please contact us.

Page Last Reviewed/Updated Thursday, April 01, 2021