Radiation Control Zones and Perimeters Recommended by Various Agencies for Responding to Radiological Emergencies
Agency | Zone Designation | Perimeter Designation | Exposure Levels | Activities and Guidelines |
---|---|---|---|---|
IAEA† |
Inside the inner cordoned area | --- | Areas with >100 mSv/h |
|
Inner Cordoned Area ("Hot zone") |
Safety Perimeter | >0.1 mSv/h |
|
|
Outer Cordoned Area |
Security Perimeter | --- |
|
|
NCRP‡ |
Dangerous Radiation Zone | Inner Perimeter |
>10 R/h (>0.1 Sv/h) |
|
Hot Zone | Outer Perimeter |
>10 mR/h (>0.1 mSv/h) |
|
|
Cold Zone | --- |
Outdoor exposure rates < 10 mR/h (<0.1 mSv/h) |
|
|
Extreme Caution Radiation Zone |
Extreme Caution Radiation Boundary |
≥10,000 mR/h (≥10 R/h) |
|
|
High Radiation Zone |
High Radiation Boundary |
1000 mR/h |
|
|
Medium Radiation Zone |
Medium Radiation Boundary |
100 mR/h |
|
|
Low Radiation Zone |
Low Radiation Boundary |
≤10 mR/h |
|
Note: See original source documents below for additional details, including benchmarks of concern for detecting focal, high levels of gamma, beta, and alpha radiation from radionuclides.
† Manual for First Responders to a Radiological Emergency, page 12, (PDF - 2.2 MB) (CTIF, IAEA, PAHO, WHO, October 2006) andGeneric Procedures for Medical Response During a Nuclear or Radiological Emergency (PDF - 2,224 KB) (IAEA, WHO, April 2005)
‡ Key Elements of Preparing Emergency Responders for Nuclear and Radiological Terrorism (NCRP Commentary No. 19), National Council on Radiation Protection and Measurements, Bethesda, MD, December 2005. Purchase required. See Responding to Radiological and Nuclear Terrorism: A Guide for Decision Makers, (PDF - 1.61 MB) (NCRP Report No. 165), Bethesda, MD, 2010.
§ Handbook for Responding to a Radiological Dispersal Device (Dirty Bomb): First Responder's Guide: The First 12 Hours (CRCPD Publication 06-6) Conference of Radiation Control Program Directors, Inc. Frankfort, Kentucky, 2006
Abbreviations:
mR/hour: milliroentgen per hour
R/hour: roentgen per hour
See also: Planning Guidance for Response to a Nuclear Detonation, Second edition, 6/2010 (PDF - 2.62 MB) (National Security Staff, Interagency Policy Coordination Subcommittee for Preparedness & Response to Radiological and Nuclear Threats)