"Key Response Planning Factors for the Aftermath of Nuclear Terrorism"

The Lawrence Livermore National Laboratory prepared this report for the Department of Homeland Security. Here are the key points:

"Despite hundreds of above-ground nuclear tests and data gathered from Hiroshima and Nagasaki, the effects of a ground-level, low-yield nuclear detonation in a modern urban environment are still the subject of considerable scientific debate.The largest potential for reducing casualtiesA during the post-detonation response phase comes from reducing exposure to fallout radiation. This can be accomplished through early, adequate sheltering followed by informed, delayed evacuation.

1. Find early, adequate shelter

It is important to be in the shelter when the fallout arrives. Fallout arrival times vary with yield and weather. If you are outside of the building-collapse area immediately surrounding the detonation, you should have several minutes before fallout arrives.

If you are outside or in a car, seek the nearest adequate shelter. Even an inadequate shelter is better than no shelter.

• Adequate shelters are locations that have as much earth, building materials, or distance between the occupants and exposed horizontal surfaces as possible. Exposed horizontal surfaces accumulate fallout. Buildings do not have to be air-tight. Broken windows do not greatly reduce the protection offered by a shelter.
• Examples of adequate shelter:
• — Basements, usually against a basement wall (in the corner). — Multistory brick or concrete structures.
• — Office buildings (central core or underground sections).
• — Multistory shopping malls (away from roof or exterior
• walls).
• — Tunnels, subways, and other underground areas.
• 
  
• Inadequate shelters include:
• — Cars, buses, and aboveground rail systems.
• — Light residential structures, such as mobile homes.
• — Single-story wood-frame houses without basements. — Single-story commercial structures without basements
• (e.g., strip malls, retail stores, and light industry).
• 
  
• 2. Perform an informed evacuation of that shelter based on three key factors:
• 
  
• -The quality of the shelter.
• - Radiation levels at the shelter site.
• - Radiation levels and travel time along the evacuation route.
• 
  
• Shelter for at least the first hour unless threatened by fire, building collapse, medical necessity, or other immediate threats.
• Once you have decided to evacuate:
• - Seek instructions and information on the location of dangerous fallout areas.
• - Identify the shortest possible evacuation route that avoids high levels of contamination. Consider tunnels, building lobbies, or other evacuation routes protected by earth, heavy building materials, and/or distance from fallout.
• - Seek local collection points (with adequate shelter) for evacuation by mass transit.
• - Consider evacuating by car if the roads have been cleared.
• 
  
• 3. Control contamination
• - Avoid outdoor exposure during the first few minutes and hours after the fallout arrives—this is the highest priority. Exposure due to contamination depositing on clothing and skin, inhalation, and ingestion are secondary concerns. Simple respiratory protection, such as a layer of cloth over nose and mouth, can mitigate contamination.
• - Remove outer clothing and shoes upon entry to shelter. Alternatively (and less preferably), brush off contamination. If possible, wipe or wash hair and exposed skin to remove fallout particles.
• 
  
• Identifying features of a nuclear detonation (not all features may be present)

An abrupt blinding flash that is visible over a large area (particularly at night).
The widespread disruption of unprotected electronic devices (EMP).
Thermal damage and burn victims well away from the blast location.

Widespread high-level radiation readings.

• A “mushroom shaped cloud” may not be generated or visible
• 
  
• Take shelter before fallout arrives

1. The most significant exposures from fallout occur in the first
2. hour after fallout arrives.
3. Seek shelter immediately if sand, ash, or rain starts to fall.

Except in areas of major building damage closest to the detonation, fallout should take at least several minutes to arrive.

• 
  
• Avoid the primary radiation hazard—external exposure to fallout
• Lawrence Livermore National Laboratory
• Fallout particles on the ground and other horizontal surfaces give off penetrating radiation; inhalation is only a minor concern.
• Shelter provided by heavy materials (concrete walls, earth, etc.) and distance from the particles on the ground are the primary sources of protection.
• The best place to find protection is in the middle or basement of a building.
• Even with broken windows, buildings can provide adequate shelter.
• 
  
• Areas of blast damage might NOT be contaminated with fallout
• 
  
• - Blast damage extends outward from the detonation in all directions, perhaps for several miles
• - Fallout proceeds downwind, contaminating only a fraction of the blast-damaged area.
• 
  
• Hazardous levels of fallout will extend into undamaged downwind areas
• 
  
• - Levels of fallout that can induce sickness from an outdoor exposure may extend 20 miles or more downwind.
• The shockwave that breaks windows travels much more slowly than the bright flash of light. This delay, up to 30 seconds or more, can increase injuries if people approach windows to investigate the bright flash."

• If you only remember one thing, this is what it should be: seek adequate shelter (think UNDERGROUND) for at least the first hour.