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
- Important transportation and communication centers.
- Manufacturing, industrial, technology and financial
- Petroleum refineries, electrical power plants and chemical
- 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
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
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
- 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
- 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
- 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
- Give your employees clear instructions about where fallout
shelters are located and what actions to take in case of
- 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 shelte, 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 or visit
the web site to obtain further information.
What To Do During A Nuclear Or Radiological
- Do not look at the flash or fireball—it can blind
- 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 In A
Public Or Home Shelter:
- 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
- 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
- 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
- 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
- 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
- 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
- Check to see that sewage lines are intact before using
- Stay away from damaged areas.
- Stay away from areas marked "radiation hazard" or
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.