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Nuclear Detonation: Weapons, Improvised Nuclear Devices



Nuclear Detonation: General Information 1

  • The energy released in a nuclear explosion derives from the splitting (fission) of radioactive materials, e.g. Uranium-235 and Plutonium-239.
  • Bombs dropped on Hiroshima and Nagasaki, Japan at the end of World War II are examples of nuclear explosions.
  • The explosive energy from a nuclear detonation is quantified in terms of the number of kilotons (Kt) of the conventional explosive TNT (trinitrotoluene) that it would take to create the same blast effect.
  • During and following a nuclear explosion, radiation is released including
  • A nuclear blast releases massive amounts of energy, which dissipate as a fireball, blast forces/waves, prompt radiation, light and heat (thermal energy), and delayed ionizing radiation (i.e. fallout: nuclear fragments created in the fission process which turn into radioactive elements which attach to vaporized debris particles from the explosion).
  • See Nuclear Detonation Effects (YouTube - 0:41 minutes) (U.S. Government archive) Watch video

  • Fireball
    • Vaporization of matter by tremendous heat within the fireball
    • Located at the epicenter of the explosion
    • Everything inside this fireball vaporizes, including soil and water, and is carried upward
    • This creates the mushroom cloud that is associated with a nuclear detonation/blast/explosion (Figure 1)
  • Blast forces/waves: shock waves causing mechanical damage (Figure 2, Figure 3, Figure 4, Figure 5, Figure 6)
    • Direct blast wave pulse overpressure forces (measured in atmospheres of pressure) propagate out from blast
    • Indirect blast wind drag forces (measured in wind velocity)
  • Prompt radiation dose
    • Radiation levels are greatest near the epicenter of the explosion, and decrease rapidly with distance from the point of the burst.
    • Carried predominantly by gamma rays and neutrons produced within the first minutes after the explosion
    • Can cause whole body exposure and Acute Radiation Syndrome, if dose is sufficient
  • Light and heat (thermal energy)
    • Radiated by the fireball
    • Wide range of electromagnetic spectrum, including infrared, visible, and UV
    • Electromagnetic pulse
      • Occurs at the instant of the detonation and ends within a few seconds
      • Disruption of the electrical grid and electronic equipment by this pulse is greatest nearest the epicenter
      • Communications infrastructure (cell towers, telecommunications switches, dishes, radar) will be significantly affected
      • Equipment entering the area after the event will function normally, but function will be related to restoration of the infrastructure
      • Cell phones and handheld radios have relatively small antennas, and if they are not connected to electrical power supplies during the electromagnetic pulse (EMP) they may not be affected
  • Delayed ionizing radiation dose (fallout) (Figure 7, Figure 8)
    • Produced by fission products and neutron-induced radionuclides in the area around the explosion, especially downwind
    • Dispersed downwind with the fireball/debris cloud
    • As the cloud travels downwind, the cooling and falling radioactive material settles on the ground, creating a large swath of deposited material (fallout)
    • Fallout creates large areas of contamination and the ionizing radiation coming off the fallout, which can damage tissues and penetrate through thin walls and glass
    • Fallout can also contaminate the soil, food, and water supply
      • Prohibitions against eating food and drinking water from affected areas will be issued
    • Groundshine (measured in dose rate per hour or cumulative dose over time interval, displayed on fallout maps. See Fallout Map 1, Fallout Map 2)
      • External gamma radiation from fission products deposited on the ground in fallout area
      • More than the beta radiation deposits, groundshine will be the most significant health hazard related to fallout in the first few days
    • See Nuclear Detonation Fallout (YouTube - 1:30 minutes) (U.S. Government archive) Watch video
    • See more details about Radiation Fallout on this page

Figure 5. Approximate distances for zones with varying yield nuclear explosions

<10 KT Explosion
  • The Severe Damage Zone will extend to ~ 1/2 mile (0.8 km)
  • The Moderate Damage Zone will be from ~ 1/2 mile (0.8 km) to ~ 1 mile (1.6 km)
  • The Light Damage Zone will extend from ~ 1 mile (1.6 km) to ~3 miles (4.8 km)
1 KT Explosion
  • The Severe Damage Zone will extend to ~ 1/4 mile (0.4 km)
  • The Moderate Damage Zone will be from ~ 1/4 mile (0.4 km) )to ~ 1/2 mile (0.8 km)
  • The Light Damage Zone will extend from ~ 1/2 (0.8 km) mile to ~2 miles (3.2 km)
0.1 KT Explosion
  • The Severe Damage Zone will extend to ~ 200 yards (0.2 km)
  • The Moderate Damage Zone will be from ~200 yards (0.2 km) to ~ 1/4 mile (0.4 km)
  • The Light Damage Zone will extend from ~ 1/4 mile (0.4 km) to ~1 mile (1.6 km)
Source: Planning Guidance for Response to a Nuclear Detonation,
Second edition, 6/2010

Figure 1. Nuclear explosion: mushroom cloud

Nuclear Explosion: Mushroom Cloud



Figure 2. Nuclear weapon explosion effects: approximate

How energy is dispersed after nuclear explosion: Approximate
Source: Armed Forces Radiobiology Research Institute's Medical Effects of Ionizing Radiation Course on CD-ROM (1999)

Figure 3. General patterns of damage from a 10-Kt nuclear explosion on the ground

Zones of damage after nuclear explosion: Generalized
Source: The National Academies and the U.S. Department of Homeland Security


Figure 4. Damage zones after a nuclear detonation: idealized maps

Zones of damage after nuclear explosion
Source: Planning Guidance for Response to a Nuclear Detonation, Second edition, 6/2010
(More detail)


Figure 6. Impacts of peak overpressure of blast

Peak Overpressure (psi)Type of StructureDegree of Damage
0.15-1WindowsModerate (broken)
3-5ApartmentsModerate
3-5HousesSevere
6-8Reinforced concrete buildingSevere
6-8Massive concrete buildingModerate
100Personnel sheltersSevere (collapse)
Peak Overpressure (psi)Type of Injury to People in the Open
5Threshold for eardrum rupture
15Threshold for serious lung damage
5050% incidence of fatal lung damage
Source: Planning Guidance for Response to a Nuclear Detonation, Second edition, 6/2010



Figure 7. Fallout: Relative rate of decline of radioactivity after a nuclear explosion

Fallout: Relative rate of decline of radioactivity after nuclear explosion
  • Summary of fallout effects from a hypothetical 10 Kt nuclear explosion.
  • The level of fallout decays quickly, roughly by a factor of 10 for every 7-fold increase in time.
Source: Armed Forces Radiobiology Research Institute's Medical Effects of Ionizing Radiation Course on CD-ROM (1999)


Figure 8. Factors that affect fallout

Particle size affects the fallout pattern
Particle size: Assuming constant wind and altitude, larger particles land relatively close to ground zero and smaller particles land farther away.
Altitude affects the fallout pattern
Altitude: The higher the initial altitude of a particle, the farther away from ground zero it lands, assuming constant wind speed and particle size. This means that the fallout pattern will be different if there is a ground burst vs. one from an altitude, and increasing altitude will also affect the fallout pattern.
Wind affects the fallout pattern
Wind: Wind is the most difficult factor to predict. Different altitudes through which a particle falls may have different wind speeds and directions that affect the final destination of the fallout particle. This explains how fallout can occur miles upwind of a detonation.
Source: Armed Forces Radiobiology Research Institute's Medical Effects of Ionizing Radiation Course on CD-ROM (1999)

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Improvised Nuclear Devices (INDs) 2

  • An illicit nuclear weapon bought, stolen, or otherwise originating from a nuclear state, or a weapon fabricated by a terrorist group from illegally obtained fissile nuclear weapons material that produces a nuclear explosion
  • Built from the components of a stolen weapon or from scratch using nuclear material (plutonium or highly enriched uranium)
  • Produces same physical and medical effects as nuclear weapon explosion
  • Results in catastrophic loss of life, destruction of infrastructure, and contamination of a very large area
  • If nuclear yield is NOT achieved, the result would likely resemble a Radiological Dispersal Device in which fissile weapons material was dispensed locally
  • If nuclear yield is achieved, results would resemble a nuclear explosion described on this page
  • Like nuclear explosions, IND explosions can be evaluated with a fallout map (See Fallout Map 1, Fallout Map 2)

Reference: Planning Guidance for Protection and Recovery Following Radiological Dispersal Device (RDD) and Improvised Nuclear Device (IND) Incidents (PDF - 519 KB) (DHS/FEMA, published in Federal Register, August 1, 2008, Z-RIN 1660-ZA02)

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Categories of Medical Effects

Blast injury | Thermal/burn injury | Radiation injuries
  • Blast injury 3, 4
    • Immediate effects of blasts and explosions
      • Primary blast injury — direct effects result from barotrauma (e.g., overpressurization and underpressurization) commonly affecting air-filled organs and air-fluid interfaces (Figure 9)
        • Rupture of tympanic membranes: Injury to ear drum: 5 psi
        • Pulmonary damage: Injury to lung: 15 psi
        • Rupture of hollow viscera: Injury fatal (LD50): 50 psi
      • Secondary blast injury
        • Penetrating trauma
        • Fragmentation injuries
      • Tertiary blast injury — effects of structural collapse and of persons being thrown by the blast wind
        • Crush injuries and blunt trauma
        • Penetrating or blunt trauma
        • Fractures and traumatic amputations
        • Open or closed brain injuries
      • Quaternary blast injury — burns, asphyxia, and exposure to toxic inhalants
    • Types of injuries caused by blasts depend on whether blasts
      • Occur outdoor in open air or within buildings
      • Cause the collapse of a building or other structure
    • Conventional bombs generate blast waves that spread out from a point source
      • Blast wave consists of two parts
        • Shock wave of high pressure followed by
        • Blast wind or air in motion
      • Damage produced by blast waves decrease exponentially with distance from the point source
      • Reverberations occur off walls and rigid objects
      • As outward energy dissipates, a reversal of wind back toward the blast and underpressurization occur
      • The resulting pressure effect damages organs, particularly at air-fluid interfaces, and the wind propels fragments and people, causing penetrating or blunt injuries
    • Enhanced-blast explosive devices (e.g., nuclear explosions) have more damaging effects than conventional explosions
      • Primary blast disseminates the explosive and then triggers it to cause a secondary explosion
      • High pressure wave then radiates from much larger area, prolonging the duration of the overpressurization phase and increasing the total energy transmitted by the explosion
      • Cause a greater proportion of primary blast injuries than do conventional devices
  • Thermal/burn injury
    • Direct absorption of thermal energy through exposed the skin or heating or ignition of clothing (flash burns) (Figure 10)
    • Indirect action of fires caused in the environment (flame burns)
    • Burn casualties — and it is expected there would be many — may result from the absorption of thermal radiation energy
    • Eye injuries
      • Flash blindness (See illustration)
        • Caused by the effect on the retina of the initial brilliant flash of light produced by the explosion
        • Victims DO NOT have to be looking at the detonation site, as reflected/diffracted light is sufficient in many cases
        • Victims driving at the time of the event will be unable to see, potentially causing large numbers of traffic accidents
        • During daylight, flash blindness does not persist for greater than about 2 minutes, but lasts generally seconds
        • At night, when the pupil is dilated, flash blindness will last longer
        • Partial recovery may be expected within 3-10 minutes in daylight, longer at night
      • Retinal scarring
        • Retinal burn (See illustration) resulting in permanent damage from scarring results when a fireball is directly viewed
        • May be sustained at considerable distances from the explosion, depending on blast size
        • Location of the scar will determine the degree of interference with vision
        • Central scarring will cause greater disability
  • Radiation injuries
    • During the incident
      • Prompt radiation
        • Gamma and neutron radiation exposure dose received within the first minutes after detonation
        • Depending on dose, patients are at risk for Acute Radiation Syndrome
      • Delayed radiation
        • Fallout (Figure 7, Figure 8): Produced by fission products and neutron-induced radionuclides in surrounding materials (water, soil, structures, nuclear device debris)
        • These radioactive products will be dispersed downwind with the fireball/debris cloud (Figure 7, Figure 8)
        • As the cloud travels downwind, the cooling and falling radioactive material settles on the ground, creating a large swath of deposited material (fallout) (Figure 7, Figure 8)
        • The highest concentrations (creating the most dangerous radiation levels) fall closest to the detonation site
        • The fallout creates large areas of contamination, and the ionizing radiation coming off the fallout contamination damages tissue and can penetrate through thin walls and glass
        • Three ways victims can get a dose of radiation from the fallout:
          • Radiation directly from the fallout as it passes by or from the fallout that has been deposited on the ground
          • Radiation from fallout contamination on skin, clothing, or possessions, which exposes people until they change their clothing and/or remove the contaminated material
          • Ingestion or inhalation of radioactive material
        • Of these, the most likely to cause injury in the first few days is direct exposure to fallout, which can be protected against using the three basic principles of time, distance, and shielding
        • Exposure to fallout is the most dangerous in the first few hours
        • Fallout decays rapidly with time:
          • Example from a hypothetical 10 Kt explosion:
            • After 3 hours, initial exposure rates are down to 20%
            • 8 hours, down to 10%
            • 48 hours, down to 1%
          • Therefore, sheltering for the first few hours can save lives
    • Long after the incident (potential long-term effects of radiation)
      • Delayed effects of acute radiation exposure
      • Specific organ effects depending on where a given isotope is incorporated
      • Carcinogenesis
      • Mutagenesis (fetal effects)

Figure 9. Blast Injuries

How blast injuries cause trauma
Source: Armed Forces Radiobiology Research Institute's Medical Effects of Ionizing Radiation Course on CD-ROM (1999)

psi = pounds per square inch
LD50 = the dose of radiation expected to cause death to 50% of those exposed without medical treatment.
 

Figure 10. Thermal burn on skin from nuclear explosion

Thermal skin burns: Example after nuclear blast
Source: Pictures of World War II, U.S. National Archives & Records Administration, 77-MDH-6.55b

Skin burn pattern corresponding to the dark portions of a kimono worn at the time of the atomic explosion, 1945.

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Medical Management 1, 5

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Communicating After an IND detonation: Resource for Responders and Officials

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Shelter in Place: Shielding by Buildings from Fallout and Blast

Buildings provide considerable protection from fallout (Figure 11), and blast (Figure 12)

  • A brick building provides better protection from radiation (Figure 11) and blast (Figure 12) than does a brick veneer building, which is better than that of a frame building.
  • Less radiation exposure (increasing the Protection Factor) is seen at interior locations and below ground
  • The multiple-story office building illustration below shows that the middle floors provide better shielding than the ground floor or exterior locations because fallout that emits gamma radiation covers the ground, exterior surfaces, and the rooftop.
  • Moving to a higher floor in the building increases the distance from the ground source but increases exposure from radiation on the rooftop.

References:

Figure 11. Buildings as radiation shielding

Example protection factors for a variety of building types and locations.
Figure 11: Example protection factors (PFs) for a wide variety of building types and locations.
  • Numbers represent a "dose reduction factor".
  • A dose reduction factor of 200 indicates that a person in that area would receive 1/200th of the dose of a person out in the open.
Source: Key Response Planning Factors for the Aftermath of Nuclear Terrorism (PDF - 4.52 MB) (Lawrence Livermore National Laboratory, August 2009, Page 12, Figure 9)


Figure 12. Selecting a safe room after an IND detonation

Selecting a safe room after an IND detonation

Source: Coleman CN, Adams S, Adrianopoli C, Ansari A, Bader JL, et al., Medical planning and response for a nuclear detonation: a practical guide. Biosecur Bioterror. 2012 Dec;10(4):346-71. (Figure 4) [PubMed Citation]


Figure 13. Blast Effects on Dwellings

How nuclear explosions affect dwellings: Examples

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Numbers and Types of Casualties from Various Computer Modeled Nuclear Detonation Scenarios

  • Table estimating medical casualty numbers and types after an IND detonation (PDF - 608 KB):
    important caveats about casualty numbers in this table
    • Generated expressly for the "Scarce Resources for a Nuclear Detonation Project", for the purpose of assisting with medical response planning.
    • Adapted from Knebel AR, Coleman CN, Cliffer KD, Murrain-Hill P, McNally R, Oancea V, Jacobs J, Buddemeier B, Hick J, Weinstock D, Hrdina CM, Taylor T, Matzo M, Bader JL, Livinski A, Parker G, Yeskey K. Allocation of Scarce Resources Following a Nuclear Detonation: Setting the Context. Disaster Med Public Health Prep. 2011 Mar;5 Suppl 1:S20-31. [PubMed Citation], Full Text (PDF - 457 KB)
    • Do not represent comprehensive modeling for all potential consequences of a nuclear detonation.
    • Do not represent data for any specific city
    • Represent only a general order of magnitude useful for medical resource planning considerations
    • Represent US government interagency computer modeling and calculations of 185 distinct nuclear detonation scenarios using many variables including
      • Nuclear detonation yields (0.1-10 kT)
      • Heights of burst (ground and air)
      • Weather conditions
      • US cities

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Radioactive Fallout

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Nuclear Testing Film Clips

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References

  1. Tochner ZA, Glatstein E, "Chapter 216: Radiation Bioterrorism," in Harrison's Principles of Internal Medicine, 17th Edition, Fauci AS, Longo DL, Kasper DL, Braunwald E, Jameson JL, Loscalzo J, Hauser SL, eds., pp. 1358-1364, McGraw Hill, 2008.
  2. Planning Guidance for Protection and Recovery Following Radiological Dispersal Device (RDD) and Improvised Nuclear Device (IND) Incidents (PDF - 519 KB) (DHS/FEMA, published in Federal Register, August 1, 2008, Z-RIN 1660-ZA02)
  3. Adapted from CDC Web site:
  4. DePalma RG, Burris DG, Champion HR, Hodgson MJ. Blast injuries. N Engl J Med. 2005 Mar 31;352(13):1335-42. [PubMed Citation]
  5. NATO Handbook on the Medical Aspects of NBC Defensive Operations (Part 1 - Nuclear), (AMEDP-6(B)), (Departments of the Army, Navy, and Air Force), Washington, DC, 1996.
  6. Recommendations for Managing a Nuclear Weapons Accident (Radiation Emergency Assistance Training Center/ Training Site [REAC/TS])
  7. A Feasibility Study of the Health Consequences to the American Population from Nuclear Weapons Tests Conducted by the United States and Other Nations (HHS/NCI/CDC, August 2001)
  8. Weisdorf D, Chao N, Waselenko JK, Dainiak N, Armitage JO, McNiece I, Confer D. Acute radiation injury: contingency planning for triage, supportive care, and transplantation. Biol Blood Marrow Transplant. 2006 Jun;12(6):672-82. [PubMed Citation]
  9. Waselenko JK, MacVittie TJ, Blakely WF, Pesik N, Wiley AL, Dickerson WE, Tsu H, Confer DL, Coleman CN, Seed T, Lowry P, Armitage JO, Dainiak N; Strategic National Stockpile Radiation Working Group. Medical management of the acute radiation syndrome: recommendations of the Strategic National Stockpile Radiation Working Group. Ann Intern Med 2004; Jun 15;140(12):1037-51. [PubMed Citation]
  10. The Medical NBC Battlebook (PDF - 9.56 MB) (US Army ChPPM, Technical Guide 244, August 2002)
  11. Radiation Emergencies: Sheltering in Place During a Radiation Emergency (HHS/CDC, May 2006)
  12. Redefining Readiness Program (Preparedness 360)
  13. Manthous CA, Jackson WL Jr. The 9-11 Commission's invitation to imagine: a pathophysiology-based approach to critical care of nuclear explosion victims. Crit Care Med. 2007 Mar;35(3):716-23. [PubMed Citation]
  14. Darley DS, Kellman RM. Otologic considerations of blast injury. Disaster Med Public Health Prep. 2010 Jun;4(2):145-52. [PubMed Citation]
  15. Morley MG, Nguyen JK, Heier JS, Shingleton BJ, Pasternak JF, Bower KS. Blast eye injuries: a review for first responders. Disaster Med Public Health Prep. 2010 Jun;4(2):154-60. [PubMed Citation]
  16. Glasstone S, Dolan PJ, The Effects of Nuclear Weapons, 3rd ed. Washington, D.C.: US Government Printing Office, 1977.
  17. Peterson KR, Shapiro CS. Internal dose following a major nuclear war. Health Phys. 1992 Jan;62(1):29-40. [PubMed Citation]
  18. Levanon I, Pernick A. The inhalation hazard of radioactive fallout. Health Phys. 1988 Jun;54(6):645-57. [PubMed Citation]
 

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