Recognition of a Nuclear Attack.
The effects of a nuclear explosion are many times greater than those
of a conventional explosion. To recognize a nuclear attack you must
know what happens when a nuclear explosion occurs. You should also
know some of the terms and elements related to nuclear hazards.
When a nuclear burst occurs, it releases a tremendous amount of
energy, called yield. Yield is measured in kilotons and megatons. A
kiloton (KT) is the equivalent amount of explosive energy released
when 1,000 tons of TNT explode. A 20 KT nuclear explosion releases as
much explosive energy as 20,000 tons of TNT. A megaton (MT) is the
equivalent amount of energy released when one million tons of TNT
explode. A 15 MT nuclear explosion releases as much energy as 15
million tons of TNT.
The nuclear explosion releases all of its energy within a fraction of
a second and within a very small area. It heats everything in that
small area, the bomb casing, unexploded nuclear fuel, dirt, trees,
buildings, so hot that it vaporizes or turns into gas. These gases
form a highly pressurized, glowing, white-hot mass called the
fireball. As the fireball cools, it rises, expands, and generates
tremendous turbulence; it causes the familiar mushroom-shaped cloud
associated with certain types of nuclear explosions.
The effect of the nuclear explosion will vary with its height of
burst, which refers to whether the explosion was at the surface of the
ground, in the air, or below ground. An airburst refers to a nuclear
explosion high enough above the earth's surface so that the fireball
does not touch the ground. An airburst will form a white cloud in the
air with a white stem.
A surface burst explodes on or close to the earth's surface. The
fireball touches the surface and produces a dark-colored and heavy-
looking cloud with a dark "mushroom stem." A subsurface burst
explodes below the surface of the earth or under water. The force of
the explosion may remain underground or break through the surface,
depending on the depth of the explosion. If the subsurface burst
stays underground, no cloud will form; it may feel like an earthquake.
The location where a nuclear weapon explodes is ground zero. Ground
zero is the point on the ground where a surface burst occurs, the
point on the ground under an airburst, or the point on the ground
above a subsurface burst.
In addition to understanding the elements of an NBC attack, you must
also understand the effects of an NBC attack on personnel, supplies,