Off-Site Emergency Planning

MEMA's Nuclear Preparedness Division is responsible for overseeing planning, training and exercises, and equipment to support the radiological emergency response for the Massachusetts population within the 10-mile emergency planning zones around our nuclear power stations. This is a peak population of approximately 252,200 persons in the vicinity of the Pilgrim Nuclear Power Station in Plymouth, Seabrook Station in New Hampshire and the Vermont Yankee Nuclear Generating Station in Vernon, Vermont.

To protect the food supply in the event of a radiological emergency, the Nuclear Preparedness Division works closely with the Massachusetts Department of Public Health Radiation Control Program in planning, training and exercises within the power stations' 50-mile radii, known as the ingestion pathway planning zones. Together, these areas comprise most of the Commonwealth of Massachusetts.

This information is also available on the MEMA Web site.


The Nuclear Preparedness Division has developed and maintains detailed radiological emergency response plans and implementation procedures for communities and facilities within the three emergency planning zones. All plans and procedures are reviewed annually, updated as needed, and tested through regular exercises. The following list summarizes the types of organizations and facilities for which plans have been developed:

  • Emergency planning zone and host communities
  • State, federal or private agencies with major response duties
  • Transportation staging areas
  • Transportation providers
  • Reception centers for the general public
  • Mass care shelters
  • Emergency worker radiological monitoring & decontamination stations
  • Schools, licensed day care facilities and children's camps
  • Nursing homes, hospitals and group homes
  • Correctional facilities

In addition, the Nuclear Preparedness Division coordinates with peripheral communities along pre-designated evacuation routes. Together with local and state police, Nuclear Preparedness Division planners have developed traffic and access control plans to support orderly and timely evacuation should it ever be necessary.

Training & Exercises

Through MEMA's Training Department, annual training is offered to all radiological emergency responders-both full-time professionals and volunteers. This consists of approximately 4,700 responders for Pilgrim Nuclear Power Station; 1,400 for Seabrook; and 650 for Vermont Yankee. In addition, MEMA conducts full-scale, federally-evaluated emergency exercises for each power plant once every two years.

Radiological Instrumentation Maintenance & Calibration Facility in Devens

The Radiological Instrumentation Maintenance & Calibration Facility located at the National Guard facility in Devens is licensed to repair and calibrate the personal dosimetry and monitoring equipment used in the nuclear preparedness program. At present, the facility primarily serves the emergency planning zone and host communities, the Massachusetts Department of Public Health Radiation Control Program, and the Commonwealth's Nuclear Incident Advisory Team, as well as other state agencies with responsibilities for radiological emergency preparedness, such as the Massachusetts National Guard.

The Radiological Instrumentation Maintenance & Calibration Facility schedules dosimetry repair and calibration work for communities throughout the Commonwealth on an as-needed basis. Communities and other emergency response organizations may request assistance from the Radiological Instrumentation Maintenance & Calibration Facility by contacting their regional MEMA office.

Potassium Iodide (KI)

Potassium iodide (KI) is a U.S. Food and Drug Administration approved over-the-counter drug that can be used to protect the thyroid gland from immediate and future radiation injury caused by radioactive iodine released during a nuclear accident.

KI saturates the thyroid gland with stable (non-radioactive) iodine, thus preventing or reducing the amount of radioactive iodine that will be taken up by the thyroid. Radiological emergencies may release radioactive iodine in the environment. Since iodine concentrates in the thyroid gland, inhalation of air or ingestion of food contaminated with radioactive iodine can lead to injury to the thyroid, including an increased risk of thyroid cancer.

It is important to note that KI is effective only against exposure to radioactive iodine and only protects the thyroid. Numerous other radionuclides may be released in an accident situation and the KI would not protect individuals from these other types of radioactivity. The primary method of protection is evacuation and sheltering-in-place, and KI should be viewed as an adjunct to these primary measures.

KI is only appropriate for the general population in a fast-moving event in which there is not enough time to leave the emergency planning zone before a release of radioiodine occurs. Additional information on the use of KI may be found at MA Dept. of Public Health.