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U.S. Department of Health and Human Services

Background Information

Casualties from a nuclear detonation result from blast, heat (thermal energy), and ionizing radiation. The distribution and severity injuries seen depends on device yield (kilotons), height of burst (air versus ground burst), atmospheric conditions (weather, wind pattern), protection afforded by shelter/topography of the terrain (e.g., urban landscape vs. rural open spaces, robustness of buildings construction)

Rescue efforts after a nuclear detonation will be complex due to potentially high radiation levels, severe infrastructural damage, the number and severity of causalities, and the inaccessibility of many victims at least initially. A summary of the key principles of the medical and public health response of the nuclear detonation is found below.

Concept of operations*: using Damage Zones to organize response activities
[*The Concept of Operations, or CONOPS, describes how the response will be organized and how the various components and sectors will relate to one another.]

Response tasks (including search and rescue) that are likely to be safe and effective are organized by four concentric physical damage zones around ground zero, some of which also include radiation. Starting from ground zero and working outward the four damage zones, for 3 sized detonations, 0.1, 1 and 10 kilotons (kT) [equivalent size of TNT] are:

  • Severe Damage (SD) Zone
  • Moderate Damage (MD) Zone
  • Light Damage (LD) Zone
  • Dangerous(DF) Fallout

Figure 1: Representative Damage and Dangerous Fallout Zones
The graphic depicts representative damage and dangerous fallout zones for 0.1 kT, 1.0 kT and 10 kT nuclear detonations.  The dangerous fallout zone is represented by a purple cigar shape originating from the blast location extending miles.  The damage zones are represented by concentric circles.  The scenario used for this playbook focuses on the 10KT detonation which is depicted as having 4 to 5 times more impact than a 1.0 kT detonation and 15 to 20 times more impact that a 0.1 kT detonation.  The full descrpition is found in the text immediately following.
Figure 1: Representative Damage and Dangerous Fallout Zones for 0.1 kT, 1.0 kT and 10 kT. A radiation exposure rate of 10 roentgens/hour (R/h) is used to delimit the DF zone. Zone shapes are idealized for illustration only; actual zones are likely to be less circular in shape and boundaries between zones are less distinct. DF zone will depend on weather conditions and height of burst. The scenario used for this playbook focuses on the 10KT detonation. (Courtesy Lawrence Livermore National Laboratory).

The following description of zone sizes is for a 10kT ground burst detonation:
Severe Damage (SD, previously called No-go) Zone

  • Description: very few buildings structurally sound or standing; radius on the order of 0.6 miles (1.0 km) from ground zero.
  • Access by rescuers will be limited by massive physical damage and high radiation levels.
  • There will be few survivors in this zone.

Moderate Damage (MD) Zone

  • Description: at the inner boundary (entry into Severe Damage/No-go zone) all buildings are fallen or structurally unstable; at the outer transition from the MD to the LD zone, there will be significant structural damage ~1 mile (1.6 km) from ground zero. Sturdier buildings (e.g., reinforced concrete) are likely to be standing; lighter commercial and multi-unit residential buildings will be unstable; houses are likely to be destroyed.
  • Limited rescue activities will be possible here.

Light Damage (LD) Zone

  • Description: inner boundary with MD zone will have more substantial building damage; outer boundary with the DF zone will have damage defined by the prevalence of broken windows (~25%) out to 3 miles (4.8 km) from ground zero; window damage tapering out to 5 miles (8 km). As responders move inward toward ground zero, windows and doors will be blown in, and gutters, roofs, and lighter construction will have increasing damage, litter and rubble will increase, and more automobiles will be stalled and crashed, making emergency vehicle passage difficult.
  • Many will self evacuate; some response efforts will be useful but difficult and dangerous, due to high radiation levels.

Dangerous Fallout (DF, some refer to as Hot) Zone

  • Description: The DF zone is distinguished not by structural damage, but by radiation levels from fallout. A radiation exposure rate of 10 roentgens/hour (R/hour) delimits the 'hot zone' exterior boundary. Inside the boundary, responder operations are severely limited by need to limit responder exposure time. The hot zone will shrink rapidly in size as the fallout decays though the boundaries of the original DF zone are important for predicting initial radiation exposure. The radioactive decay rule of thumb: exposure rate from fallout declines 90% every 7 hours. {At 14 hours it is approximately 1% of what it was at 1 hour}.
  • Fallout particles may be visible as fine sandy materia. l, either actively falling out as the plume passes, or visible on clean surfaces. Visible fallout provides strong evidence of dangerous levels of radioactivity, but, fallout may not be noticeable on rough or dirty surfaces, and no method is available to reliably estimate radiation dose rates based on the quantity of visible fallout. Therefore, visible fallout may possibly be used as an indicator of a direct radiation hazard, but the lack of apparent fallout should not replace appropriate radiation measurements.
  • Responders should refrain from undertaking missions in areas where radioactivity may be present until radiation levels can be accurately determined and readily monitored. Any response operations within the hazardous DF zone must be justified, brief, and well-planned.
  • Prior to an incident, local protocols should be created that define operations in radiation-contaminated areas and optimize exposure risk versus the benefits of the potential missions.

A fifth zone, circumscribed by a “line” reflecting an environmental exposure rate of 0.01 R/h, is also useful in managing the response. It is in Figure 2, below. It has also been called “a Radiation Caution Zone”. This “line” and the zone within it will enlarge initially as fallout is deposited but will then contract quickly, as radiation levels decrease due to rapid radioactive decay in the hours and days after a blast. This is not a damage zone per se, but it is area outside the DF zone where response activities can be conducted. However, responder time will be limited by federal Protective Action Guides or recommendations adopted by the local Incident Commander. The ALARA (As Low As Reasonably Achievable) principle will also apply (keeping radiation levels for responders as low as reasonably achievable (

Number and spectrum of injuries
There will be hundreds of thousands of casualties. Injuries will vary by type and severity. Many people will have trauma only (especially in and beyond LD zones), others will have radiation exposure only (especially in DF zone), and some will have both. The list below reflects the major kinds of injuries expected.

  • Blast: from pressure wave, tumbling and crush injuries; puncture injuries from flying debris, rather than pressure-related injuries dominate because those who would have sustained classical blast injuries are likely due to have been killed by the exceptional radiation doses or burns levels in the zone where classical blast injuries would be sustained.
  • Burns: thermal energy from the detonation and burns from secondary fires and contact with hot materials during the failure of a building (Note: It may be difficult to distinguish superficial thermal from radiation burns without patient history).
  • Radiation: prompt radiation (instantaneous and high dose rate from detonation) and fallout (lower dose rate with most of dose being given in first few hours)- depends on location and duration of exposure. Sheltering-in-place in the hours following the detonation is important to reduce radiation dose.
  • Combined injury: defined as radiation plus blast and/or burn. This has a worse prognosis than either alone.
  • Multiple blunt trauma and lacerations: resulting from motor vehicle accidents that are a consequence of flash-blindness from detonation (the blindness lasts a few minutes, worse at night when pupils dilated). This may occur miles away, especially at night when pupils are dilated so that flash may have greater impact.
  • Punctures and lacerations: from glass breakage may be at distances up to miles from the detonation point.


  • Prompt radiation from the detonation will produce very high instantaneous doses but will not contaminate people.
  • Contamination comes from radioactive fallout alighting on the individual. People inside shelters will not have superficial contamination unless they go outside. Individuals evacuating from shelters later may contaminate their shoes and clothing in transit through the DF zone.
  • Life-saving interventions by responders take precedence over decontamination, as long as they occur in areas that are considered safe for responders.
  • Decontamination is a responsibility of the state and local responders and also of individuals. The need for decontamination as soon as possible after the incident and the time it takes federal assets to arrive makes it crucial for state and local entities to manage this function, although guidance may be available from federal authorities.
  • Removing outer garments and shaking out hair removes 90% or more of external contamination. Thus control of removed clothing is a priority for containment of radiation.
  • Managing internal contamination from inhalation or ingestion is not considered a significant part of the initial response. Therefore, there is no initial role for KI (potassium iodide), Prussian Blue or chelating agents (e.g., DTPA).

Response Worker Safety

Search and rescue operations will be markedly impeded by the relatively high levels of radiation in and around the MD zone. Protective Action Guides (PAGs) and the As Low As Reasonably Achievable (ALARA) principle will guide actions ( Safeguards for responders include but are not limited to the following:

  • Personal Protective Equipment (PPE) - will protect emergency workers from contaminants but will not protect against external radiation doses.
  • Respirator or Self-Contained Breathing Apparatus - will protect workers from breathing in radioactive particulates.
  • Real time personal electronic dosimeters - will provide readings to alert emergency workers as to when exposure levels are about to exceed worker safety limits (PAGs) or other locally determined guidelines.
  • "Turn around times" - by knowing radiation levels in the work area, turn around times can be calculated to account for worker entry, time on task, worker exit from the radiation zone.


  • When working in areas approved for search and rescue, emergency Medical Services (EMS) workers will use their customary field triage system which is based initially on the physical injury (e.g., START, jumpSTART, SALT, DIME. Referenced on REMM web portal).
  • If resource adequacy is limited, the standard order for triage and transportation (sickest first) may need to change, as noted in the next section.
  • Given the magnitude of the incident and the limited size of the EMS response assets available, most people will reach medical care without having been screened in the field.
  • Radiation dose can be estimated very roughly by the physical location of the individual at the time of detonation and after. When available, blood counts or the clear presence of cutaneous radiation burns can be used to better determine dose estimates. Many casualties will not have been exposed to any radiation.
  • Time to vomiting after exposure is one simple way to estimate dose. However, because vomiting can result from many causes besides radiation, it is not considered particularly accurate.
  • Diagnosis of Acute Radiation Syndrome (ARS) and its organ sub-syndromes:
    • Hematological Syndrome: clinically relevant acute injury occurs typically at doses above 2-3 Gy, although lower doses may be detectable with CBCs and other tests. For victims with doses > 2 Gy, immediate treatment with myeloid cytokines is indicated (e.g., G-CSF). Best effects occur when administered within 24 hours of exposure. Hematologic injury may become detectable 1-3 weeks after exposure, after a latent phase without signs or symptoms.
    • Gastrointestinal Syndrome: usually results after doses above 5-6 Gy; occurs within a few days of exposure; can be managed with aggressive treatment.
    • Neurovascular Syndrome: typically results from doses above 10 Gy; almost always fatal, but will benefit from palliative/compassionate care.
  • Triage and management by dose of whole body exposure: general principles, with the understanding that precise dose estimation initially may be difficult:
    • <2 Gy: follow-up only (possibly for biodosimetry assessment later).
    • 2-4 Gy: evaluation and expert monitoring within 1-3 weeks of exposure, with myeloid cytokines if supplies are adequate.
    • >4 Gy: immediate medical attention, including myeloid cytokine treatment as soon as possible.
    • >10 Gy: palliative/compassionate care.
  • Combined injury: defined as significant physical trauma (and burns > 20% of the total body surface area) in conjunction with radiation dose of >2 Gy; has much worse prognosis than either injury alone. People with only minor trauma plus radiation will be triaged and managed the same as those with radiation only using radiation dose as outlined above.

Scarcity of Resources affects Triage Priority and Standards of Care

  • Scarcity of medical resources (e.g., staff, space, equipment, medicines) will vary greatly by location of the medical care facility and time after the incident; this will affect how victims are triaged and cared for.
  • Conventional triage attends to the “sickest first”. Resource scarcity after a nuclear detonation will result in a change of triage priority in order to provide the greatest good to the greatest number which includes providing palliative/comfort care. With severe scarcity, the sickest victims who require intensive rescue resources may no longer be assigned first priority.
  • “Standards of Care” available to victims will be affected by resources scarcity. It is expected that at least initially in near-by locations provision of care may need to change from conventional to contingency (functionally equivalent) and then to crisis for some period of time.
  • Each institution should have a plan to determine when and how it plans to change from normal or conventional triage guidelines and standards of care. It is crucial that these decisions be made by senior managers and the reasons be communicated promptly and effectively to staff and the public. This will help to minimize chaos, inconsistency, excessive stress in decision-making, and ensure adequate liability protections for practitioners.
  • It is essential the victim be reassessed and re-triaged iteratively because resource adequacy may change rapidly over time. It is expected that close-in facilities will experience marked resource limits initially followed by improvement subsequently, as assets begin to arrive after 24-48 hours.

Organization of medical response

Venues for the medical response

The Radiation TReatment, TRiage and TRansport System (RTR System) presents a functional approach to the various activities of the medical response. The figure below illustrates the various kinds of activities and where they would likely be located in relation to the zones of response noted above and regional assets. There will likely be multiple RTR 1, 2 and 3 sites each with different types of activities. Using this terminology allows responders to have common language for situational awareness, deployment or resources, and planning.

The medical response following a nuclear detonation requires identification of Assembly Centers (AC) and Medical Care (MC) centers equipped to handle medical surge and the ability to assess where the damage zones are located relative to the AC and MC sites. The medical response is organized following the RTR system and MedMap. The MedMap is an HHS system that contains GIS-based information on many aspects of the response. It can be accessed on an as-needed basis in coordination with HHS.

RTR system and MedMap

Figure 2. The RTR system and damage zones.
The graphic depicts a conceptualized representation of the Radiation TReatment, TRiage and TRansport System (RTR System) as an overlay to the damage zone structure.  The full descrpition is found in the text immediately following.
The RTR system and damage zones. Explanations and abbreviations described in text.

RTR Response Organization System (Radiation TReatment, TRiage and TRansport). The RTR is a functional approach, with a focus on TRiage, TReatment, and TRansport. There will likely be multiple RTR 1, 2 and 3 sites. The designation of three subtypes is to help organize the response that allows a common understanding and language for situational awareness, deployment or resources, and planning.

  • RTR 1, 2, and 3 sites are formed spontaneously and are designated/determined in real-time during an incident by the Incident Commander and responders. Sites are designated based on the previously described physical damage zones which will inform assumptions regarding the availability of access and transportation and the potential casualty population.
  • There will be multiple RTR 1, 2, and 3 sites, many of which will form as victims aggregate.
  • Medical Care (MC), Assembly Centers (AC), Evacuation centers and points of distribution can largely be preplanned at predetermined sites.
  • MedMap is a GIS based mapping system used by HHS for response planning and situational awareness. It will be shared among response organizations when needed.
  • MedMap uses a mapping base with a variety of data overlays (e.g. number of available beds, locations of deployed personnel, caches, roads, schools, weather, etc), and key geographically modeled or actually sampled radiation level data, updated over time, from IMAAC (Interagency Modeling Atmospheric Advisory Center).

RTR 1 sites will be near the SD zone and within the MD zone. Physical infrastructure damage and radiation will limit the ability both to reach the victims and to help evacuate and administer medical support. Over time, the radiation dose will decrease and victims who had adequate shelter may conceivably survive.

  • Many or most affected persons are non-ambulatory, or soon will be; victims will have physical trauma, burns, acute radiation syndrome, and combined injuries, making evacuation very difficult.
  • Based both on their proximity to the blast and on time to onset of symptoms, it will be clear that many of the victims will have lethal traumatic and/or radiation injuries and will require primarily comfort care, if available.
  • Because of ambient radiation levels and limited supplies, individual emergency medical responders will have very limited periods of time to work safely in this environment. It may be possible to extract some victims, provide instructions to ambulatory people and provide some palliation.
  • Transportation will be extremely limited and delayed after such a large incident and response assets will be difficult to deploy. As the fallout decays, these sites will be safer for responders to enter.

RTR2 sites will have radiation that will limit the time for responders and victims to be present with acceptable risk. Most of these will be within the LD zone and DF zone.

  • Most victims will be ambulatory, and many fewer victims will have combined injuries. Many victims may have significant radiation exposure from fallout.
  • The time constraints for responders must be carefully monitored due to ambient radiation within the DF zone.
  • Self-decontamination will be possible once people are outside of the area, at least the removal of surface contamination of individuals through control of clothing.
  • Transportation may still be delayed reaching these sites in the LD zone due to broken glass and debris.

RTR3 sites will be away from the LD and DF zones and will not have radiation that appreciably limits the victims’ and responders’ time there. Glass and blast damage may be present miles from the epicenter where the conditions are not complicated by radiation so structural damage to buildings does not necessarily mean radiation is present.

  • Almost all victims will be ambulatory and many people may have minor to no injuries and no significant radiation exposure. Some will be displaced persons whose homes will be uninhabitable and/or unreachable for some period of time.
  • The time constraints for responders’ presence at these sites will reflect regular disaster shift schedules and will not be limited by ambient radiation. Local physical dose monitors and radiation safety officers will alert the Incident Commander and/or Safety Officer if an RTR3 site becomes contaminated. Contamination of an RTR3 site may result in its movement to a clean location or in moving the people to an AC site.
  • For those who arrive from the DF zone, self-decontamination will be possible- at least the removal of surface contamination of individuals.
  • Symptomatic treatment including basic wound care can be administered if appropriate, prior to transportation.
  • Following triage and initiation of minor treatments where applicable, available transportation assets will evacuate victims to MC or AC sites as appropriate, some of which may be at a substantial distance.
  • Radiation monitoring devices and people who know how to calibrate and use them may be available at RTR3 sites. Transportation will be available here, and it is important to minimize contamination of health and shelter facilities and transport vehicles.
  • RTR3-related infrastructure will be relatively intact, so roads and logistics should not impose serious limitations to the capabilities at these sites. Control of the evacuation and transport routes will be vital, and will be greatly facilitated by civilians abiding by public messages.

Medical Care (MC) sites may include

  • Hospitals, medical centers, and other health care facilities such as nursing homes and medical clinics, alternate care facilities such as Federal Medical Stations; and
  • Distant, even nationwide medical facilities (such as Radiation Injury Treatment Network sites, cancer centers, burn centers, trauma centers).
  • Some of the facilities nearest to the blast will not be operational due to loss of infrastructure and others may not be useable, at least for a period of time, due to their location within or near the fallout.
  • If response caches have been mobilized to the appropriate areas, or are available locally, it may be possible to initiate some treatment for mitigation of acute radiation syndrome (e.g. cytokines) and to provide symptomatic treatment to affected people who are being prepared for evacuation.

Assembly Centers (AC) will be

  • Evacuee-receiving registry centers and temporary shelters where people may receive food and shelter and/or will check in with authorities so that they can be accounted for after the incident.
  • Screening forms or assessment of radiation exposure may also occur at these sites, but the purpose is not generally medical care, though they may be co-located with a medical care (MC) site.
  • People may arrive directly or may have been directed from RTR and MC sites.
  • AC sites differ from RTR3 sites in that they will have been pre-designated but RTR3 sites may serve as ACs.

Evacuation centers and drop zones

  • Hubs for major victim and evacuee transport by land, rail, air, and water.
  • May be for incoming supplies and personnel and/or for outgoing exposed/displaced persons.

Summary of Anticipated Operations

Intent of Operations
All response and recovery planning and operational activities should be initiated and executed in compliance with the National Response Framework (NRF), National Incident Management System (NIMS), and the HHS ESF #8 Concept of Operations Plan for Public Health and Medical Emergencies. Nuclear detonation response and recovery planning should focus on developing and coordinating collaborative, interagency and multi-jurisdictional operational activities and capabilities to provide for:

  1. Patient and At-Risk Population Evacuations
  2. Life-Saving Operations
  3. Life-Sustaining Operations
  4. Restoration of Public Health and Medical Infrastructure
  5. Human Services and At-Risk Population Needs
  6. Patient Return to Location of Origin
  7. Veterinary Assistance (service animals)
  8. Fatality Management
  9. Worker Safety and Health

Response and initial recovery planning and operational activities will consider medical evacuation and shelter-in-place (SIP) options and resources for individuals with medical needs in hospitals, nursing homes, assisted living facilities, and persons living at home. Individuals with functional needs, including individuals with disabilities and individuals with limited English proficiency, that do not require medical support/intervention but do require other means of support such as the assistance of an interpreter, the assistance of a personal caregiver to accomplish activities of daily living or the assistance of a caregiver to provide guidance in daily decision-making, or other auxiliary aid or service is a shared responsibility between Mass Care and Medical And Public Health responsibilities.

Response Considerations

  • Initial response will be local and regional. While some Federal resources may start arriving by 12-24 hours, they are not likely to arrive in significant numbers until 24-48 hours.
  • Early Federal Response. Initial federal resources will include weather information and modeling (from Interagency Modeling and Atmospheric Advisory Center (IMAAC), some supplies from Strategic National Stockpile, emergency declarations and subject matter experts on scene or available.
  • Early Triage and Transport. The local emergency response and EMS systems will be overwhelmed and mutual aid will be required. Most people will likely reach medical care by self-evacuation.
  • Communication. Directing people to shelter-in-place and where to go for medical care and for assembly centers will have major impact on survivability, and must be done in the first minutes to hours after an incident – requiring pre-incident scripting.
  • Responder Safety and Health. Adequate provisions and training for protecting safety and health of responders is a strategic objective. Exposure limits should be predetermined by the locality in an effort to optimize exposure risk versus mission necessity and requirements. General rules should be established in advance by Incident Commanders (guidance information available in Planning Guidance).
  • Limiting Effects of Electromagnetic Pulse (EMP). EMP and physical damage to electric grid and communications equipment will impact response up to a few miles but much of surrounding infrastructure will be intact. EMP is instantaneous. It will not impact any equipment brought into the area which will work, but is likely to limit availability of directly impacted medical equipment and vehicles.

Organization of Playbook

This playbook contains actions steps which outline the medical and public health response to a nuclear detonation while allocating scarce resources. In essence, it presents the response by a complex system. The action steps stages are outlined below:

The medical response unfolds in stages

  1. Phase 0: Pre-incident Preparation (and possibly some ramp-up may be possible if there is intelligence indicating heightened risk)
  2. Phase I: Early phase- 0-24 hours
  3. Phase II: Intermediate phase- 24-96 hours (in addition to ongoing 24 hours)
  4. Phase III: Later phase- >96 hours


  1. Emergency medical services (EMS)
  2. Healthcare facility
  3. Public health
  4. Medical system coordination (ESF-8)
  5. Evacuee medical care and fallout-related radiation illness
  6. Recovery / Resilience (not a focus of this document and thus limited guidance provided)

Also contained in this playbook are additional resources. These resources serve as informative references with definitions, discussion points, and recommendations about topics related to medical response to a nuclear detonation. The information contained in the resource section is to be used in concert with the Action Steps.

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  • This page last reviewed: February 14, 2012