Nuclear and Radiological Attack
Nuclear explosions can cause deadly effects—blinding light, intense heat (thermal
radiation), initial nuclear radiation, blast, fires started by the heat pulse, and
secondary fires caused by the destruction. They also produce radioactive particles
called fallout that can be carried by wind for hundreds of miles.
Terrorist use of a radiological dispersion device (RDD)—often called "dirty nuke"
or "dirty bomb"—is considered far more likely than use of a nuclear device. These
radiological weapons are a combination of conventional explosives and radioactive
material designed to scatter dangerous and sub-lethal amounts of radioactive material
over a general area. Such radiological weapons appeal to terrorists because they require
very little technical knowledge to build and deploy compared to that of a nuclear
device.
Also, these radioactive materials, used widely in medicine, agriculture, industry
and research, are much more readily available and easy to obtain compared to weapons
grade uranium or plutonium. Terrorist use of a nuclear device would probably be limited
to a single smaller "suitcase" weapon. The strength of such a weapon would be in the
range of the bombs used during World War II. The nature of the effects would be the
same as a weapon delivered by an intercontinental missile, but the area and severity
of the effects would be significantly more limited. There is no way of knowing how
much warning time there would be before an attack by a terrorist using a nuclear or
radiological weapon.
A surprise attack remains a possibility. The danger of a massive strategic nuclear
attack on the United States involving many weapons receded with the end of the Cold
War. However, some terrorists have been supported by nations that have nuclear weapons
programs. If there were threat of an attack from a hostile nation, people living near
potential targets could be advised to evacuate or they could decide on their own to
evacuate to an area not considered a likely target. Protection from radioactive fallout
would require taking shelter in an underground area, or in the middle of a large building.
In general, potential targets include:
- Strategic missile sites and military bases.
- Centers of government such as Washington, D.C., and state capitals.
- Important transportation and communication centers.
- Manufacturing, industrial, technology and financial centers.
- Petroleum refineries, electrical power plants and chemical plants.
- Major ports and airfields.
Taking shelter during a nuclear attack is absolutely necessary. There are two kinds
of shelters—blast and fallout. Blast shelters offer some protection against blast
pressure, initial radiation, heat and fire, but even a blast shelter could not withstand
a direct hit from a nuclear detonation. Fallout shelters do not need to be specially
constructed for that purpose. They can be any protected space, provided that the walls
and roof are thick and dense enough to absorb the radiation given off by fallout particles.
The three protective factors of a fallout shelter are shielding, distance, and time.
Shielding. The more heavy, dense materials—thick walls, concrete, bricks, books and
earth—between you and the fallout particles, the better.
Distance. The more distance between you and the fallout particles, the better. An
underground area, such as a home or office building basement, offers more protection
than the first floor of a building. A floor near the middle of a high-rise may be
better, depending on what is nearby at that level on which significant fallout particles
would collect. Flat roofs collect fallout particles so the top floor is not a good
choice, nor is a floor adjacent to a neighboring flat roof.
Time. Fallout radiation loses its intensity fairly rapidly. In time, you will be able
to leave the fallout shelter. Radioactive fallout poses the greatest threat to people
during the first two weeks, by which time it has declined to about 1% of its initial
radiation level.
Remember that any protection, however temporary, is better than none at all, and the
more shielding, distance and time you can take advantage of, the better. Most electronic
equipment within 1,000 miles of a highaltitude nuclear detonation could be damaged
by EMP.
Electromagnetic Pulse
In addition to other effects, a nuclear weapon detonated in or above the earth's atmosphere
can create an electromagnetic pulse (EMP), a high-density electrical field. EMP acts
like a stroke of lightning but is stronger, faster and briefer. EMP can seriously
damage electronic devices connected to power sources or antennas. This include communication
systems, computers, electrical appliances, and automobile or aircraft ignition systems.
The damage could range from a minor interruption to actual burnout of components.
Most electronic equipment within 1,000 miles of a high-altitude nuclear detonation
could be affected. Battery powered radios with short antennas generally would not
be affected. Although EMP is unlikely to harm most people, it could harm those with
pacemakers or other implanted electronic devices.
What To Do Before A Nuclear Or Radiological Attack
- Learn the warning signals and all sources of warning used in your community. Make
sure you know what the signals are, what they mean, how they will be used, and what
you should do if you hear them.
- Assemble and maintain a disaster supply kit with food, water, medications, fuel and
personal items adequate for up to 2 weeks—the more the better.
- Find out what public buildings in your community may have been designated as fallout
shelters. It may have been years ago, but start there, and learn which buildings are
still in use and could be designated as shelters again.
- Call Environmental Health and Safety Services on campus.
- Look for yellow and black fallout shelter signs on public buildings. Note: With the
end of the Cold War, many of the signs have been removed from the buildings previously
designated.
- If no noticeable or official designations have been made, make your own list of potential
shelters near your home, workplace and school: basements, or the windowless center
area of middle floors in high-rise buildings, as well as subways and tunnels.
- Give your employees clear instructions about where fallout shelters are located and
what actions to take in case of attack.
- If you live in an apartment building or high-rise, talk to the manager about the safest
place in the building for sheltering, and about providing for building occupants until
it is safe to go out.
- There are few public shelters in many suburban and rural areas. If you are considering
building a fallout shelter, keep the following in mind:
- A basement, or any underground area, is the best place to shelter from fallout. Often,
few major changes are needed, especially if the structure has two or more stories
and its basement - or one corner of it - is below ground.
- Fallout shelters can be used for storage during non-emergency periods, but only store
things there that can be very quickly removed. (When they are removed, dense, heavy
items may be used to add to the shielding.)
- See the Tornado Instructions section for information on areas which could be used as shelter in the event of a
nuclear detonation or for fallout protection, especially in a building without a basement.
- All the items you will need for your stay need not be stocked inside the shelter itself
but can be stored elsewhere, as long as you can move them quickly to the shelter.
- Learn about the university's evacuation plans. Such plans may include evacuation routes,
relocation sites, how the public will be notified and transportation options for people
who do not own cars and those who have special needs.
- Acquire other emergency preparedness booklets that you may need. Contact Environmental Health and Safety Services to obtain further information.
What To Do During A Nuclear Or Radiological Attack
- Do not look at the flash or fireball - it can blind you.
- If you hear an attack warning:
Take cover as quickly as you can, BELOW GROUND IF POSSIBLE, and stay there unless
instructed to do otherwise.
- If you are caught outside, unable to get inside immediately, take cover behind anything
that might offer protection. Lie flat on the ground and cover your head.
- If the explosion is some distance away, it could take 30 seconds or more for the blast
wave to hit.
- Protect yourself from radioactive fallout. If you are close enough to see the brilliant
flash of a nuclear explosion, the fallout will arrive in about 20 minutes. Take shelter,
even if you are many miles from ground zero—radioactive fallout can be carried by
the winds for hundreds of miles. Remember the three protective factors: shielding,
distance and time.
- Keep a battery-powered radio with you, and listen for official information. Follow
the instructions given. Local instructions should always take precedence: officials
on the ground know the local situation best.
What To Do After A Nuclear Or Radiological Attack
- Do not leave the shelter until officials say it is safe. Follow their instructions
when leaving.
- If in a fallout shelter, stay in your shelter until local authorities tell you it
is permissible or advisable to leave. The length of your stay can range from a day
or two to four weeks.
- Contamination from a radiological dispersion device could affect a wide area, depending
on the amount of conventional explosives used, the quantity of radioactive material
and atmospheric conditions.
- A "suitcase" terrorist nuclear device detonated at or near ground level would produce
heavy fallout from the dirt and debris sucked up into the mushroom cloud.
- A missile-delivered nuclear weapon from a hostile nation would probably cause an explosion
many times more powerful than a suitcase bomb, and provide a greater cloud of radioactive
fallout.
- The decay rate of the radioactive fallout would be the same, making it necessary for
those in the areas with highest radiation levels to remain in shelter for up to a
month.
- The heaviest fallout would be limited to the area at or downwind from the explosion,
and 80% of the fallout would occur during the first 24 hours.
- Because of these facts and the very limited number of weapons terrorists could detonate,
most of the country would not be affected by fallout.
- People in most of the areas that would be affected could be allowed to come out of
shelter and, if necessary, evacuate to unaffected areas within a few days.
- Although it may be difficult, make every effort to maintain sanitary conditions in
your shelter space.
- Water and food may be scarce. Use them prudently but do not impose severe rationing,
especially for children, the ill or elderly.
- Cooperate with shelter managers. Living with many people in confined space can be
difficult and unpleasant.
Returning To Your Home Or Office
- Keep listening to the radio for news about what to do, where to go, and places to
avoid.
- If your home was within the range of a bomb's shock wave, or you live in a high-rise
or other apartment building that experienced a non-nuclear explosion, check first
for any sign of collapse or damage, such as:
- toppling chimneys, falling bricks, collapsing walls, plaster falling from ceilings.
- fallen light fixtures, pictures and mirrors.
- broken glass from windows.
- overturned bookcases, wall units or other fixtures.
- fires from broken chimneys.
- ruptured gas and electric lines.
- Learn how to build a temporary fallout shelter to protect yourself from radioactive
fallout even if you do not live near a potential nuclear target.
- Immediately clean up spilled medicines, drugs, flammable liquids, and other potentially
hazardous materials.
- Listen to your battery-powered radio for instructions and information about community
services.
- Monitor the radio and your television for information on assistance that may be provided.
Local, state and federal governments and other organizations will help meet emergency
needs and help you recover from damage and losses.
- The danger may be aggravated by broken water mains and fallen power lines.
- If you turned gas, water and electricity off at the main valves and switch before
you went to shelter:
- Do not turn the gas back on. The gas company will turn it back on for you or you will
receive other instructions.
- Turn the water back on at the main valve only after you know the water system is working
and water is not contaminated.
- Turn electricity back on at the main switch only after you know the wiring is undamaged
and the community electrical system is functioning.
- Check to see that sewage lines are intact before using sanitary facilities.
- Stay away from damaged areas.
- Stay away from areas marked "radiation hazard" or "HAZMAT."
Threat Conditions
There is always a risk of a terrorist threat. Each threat condition assigns a level
of alert appropriate to the increasing risk of terrorist attacks:
- Low Condition (Green)
- This condition is declared when there is a low risk of terrorist attacks.
- Guarded Condition (Blue)
- This condition is declared when there is a general risk of terrorist
- High Condition (Orange)
- A High Condition is declared when there is a high risk of terrorist attacks.
- Severe Condition (Red)
- A Severe Condition reflects a severe risk of terrorist attacks. Under most circumstances,
the protective measures for a Severe Condition are not intended to be sustained for
substantial periods of time.
