The Effects of Nuclear Weapons: Terrorist Threat
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Transcript of The Effects of Nuclear Weapons: Terrorist Threat
The Effects of Nuclear The Effects of Nuclear Weapons: Weapons: Terrorist ThreatTerrorist Threat
PurposePurpose
The purpose of this presentation is to provide the reader with an overview of nuclear weapons and their effects.
Topics will include:– Types of weapons– Energy release– Types of Detonation– Historical Information– Effects
Nuclear Weapons vs Nuclear Weapons vs Radioactive Dispersal Device Radioactive Dispersal Device (RDD or Dirty Bomb)(RDD or Dirty Bomb) Nuclear weapons
– Use conventional explosives to create super-critical mass of fissionable nuclear material
– Super-critical mass is capable of self-sustaining, prompt, uncontrolled chain reaction
– Resultant explosive yield can be orders of magnitude higher than possible with conventional materials
RDD– Use conventional explosives to spread or disperse
radioactive material– No chain reaction or nuclear yield – In most cases the explosion will cause more damage
than the radioactive material dispersion
Remaining discussionRemaining discussion
The remainder of this presentation describes nuclear weapons
For further information on RDD weapons see:– http://www.bt.cdc.gov/radiation/pdf/di
rtybombs.pdf– http://www.nrc.gov/reading-rm/doc-
collections/fact-sheets/dirty-bombs.pdf
Nuclear Weapons TypesNuclear Weapons Types Fission devices
– Uranium (235U) or Plutonium (239Pu)
– Gun Type
• Explosively combine two sub-critical assemblies
– Implosion Type
• Symmetrically implode a sphere of sub-critical density
• Required for 239Pu
– Terrorist Threat
• Stolen military device
• Improvised Nuclear Device (IND), i.e. “home made”
• 235U Gun-type Weapon easiest to construct
• Likely 20 kT or less
Nuclear Weapons Types, Nuclear Weapons Types, con’t.con’t.
Thermonuclear (Fusion) devices
– Unlikely to be a terrorist device
–Military application
– High-technology
Energy Equivalents of one Energy Equivalents of one Kiloton of TNTKiloton of TNTComplete burn-up (fission) of 56 g
(~2 ounces) of 235U or 239Pu1.15 x 106 kilowatt-hours1.8 x 109 British thermal units14,500 Gallons of Gasoline4/5 the energy produced by the
Hoover Dam in 1 hour
Types of Detonations from a Types of Detonations from a Terrorist ThreatTerrorist ThreatMost likely– Surface: Truck– Underwater: Boat
Less likely– Air: Private plane– Sub-surface: Subway
Least likely– High Altitude: Military Delivery Only
Distribution of Energy of Distribution of Energy of an Air Burst below an Air Burst below 100,000 ft100,000 ft
Blast and Thermal accountfor 85% of the Energy released
Nuclear Weapon Experience Nuclear Weapon Experience Two non-testing detonationsTwo non-testing detonations
Hiroshima – Little Boy– 235U Gun-Type
Device
Nagasaki– Fat Man– 239Pu Implosion
Device
Results of a Nuclear Results of a Nuclear ExplosionExplosion
80,000 deaths in Hiroshima and 20,000 deaths in Nagasaki
Nearly all deaths due to Blast and Thermal
Few deaths attributed to Radiation– Prompt or Delayed
Results of a Nuclear Results of a Nuclear ExplosionExplosion Expect few, if any, survivors near
ground-zero However, little experience in “urban”
environment Buildings will provide shielding– Blast– Thermal– Radiation
Residual radioactive environment, significant impact on rescue operations
Hiroshima BeforeHiroshima BeforeHiroshima After
Weapon EffectsWeapon Effects
Prompt effects higher with airburst– Blast– Thermal– Prompt Radiation– Prompt effects 30-50% reduced with surface
burst– Electromagnetic Pulse (EMP)
• Primarily results from a high-altitude explosion• Not a likely effect from a terrorist detonation
Residual effects higher with surface burst– Residual Radioactivity (Fallout)
Weapon EffectsWeapon Effects(Based on a 20 kt low-altitude (Based on a 20 kt low-altitude Airblast)Airblast)
Peak shock wave overpressure–~14 psi @ ¼ mile
Thermal energy–~18 cal/cm2 @ 1 mile
Prompt radiation dose– Neutron ~ 0.8 Gy @ 1 mile – γ-ray ~ 1.2 Gy @ 1 mile
Residual Radiation Residual Radiation (Fallout)(Fallout) Difficult to predict impact to a specific
area Depends on:– Type of weapon– Type of burst
• Air• Surface
– Wind patterns– Terrain
• Little data for an “Urban” Environment
Fallout, con’t.Fallout, con’t.
Decay rate:
t can be any time unit
Average photon energy ~0.7 MeV
SummarySummary A terrorist use of a nuclear weapon would most likely
involve:– 235U Gun-type device– Surface detonation– Yield of 20 kt or less
The major injuries and effects would be caused by:– Blast and shock– Thermal
Rescue efforts pertain mostly to injuries distant from ground zero
Radiation protection necessary for rescue of shielded survivors nearer ground zero
Little experience with explosion in an “Urban” environment
ReferencesReferences Glasstone and Dolan, “The Effects of Nuclear
Weapons,” Published by US DoD and Energy Research and Development Administration, Washington DC, 1977.
Ferguson and Potter, “The Four Faces of Nuclear Terrorism,” Monterey Institute – Center for Nonproliferation Studies, Monterey, CA, 2004.
Auxier J, “The Effects of Nuclear Weapons,” Health Physics Summer School, Gaithersburg, MD, July 2004.
Public Protection from Nuclear, Chemical and Biological Terrorism, Ed. by Brodsky, Johnson and Goans, Medical Physics Publishing, Madison, WI, 2004.