minutes, dispersion of the pool and radioactive decay
An airburst or a smaller weapon will reduce
will have reduced the hazard to one of tactical
fallout. Also, the complete containment of an
insignificance. During the early expansion phase of
underground burst will eliminate fallout.
this pool, a dose rate of several thousand rad/hr may
Fallout landing on water will sink and will not be a
exist at the water surface.
hazard to ships that pass through the area after the
fallout has stopped coming down. Fallout over a land
area will remain on the surface and will be a hazard to
personnel living in or passing through the area.
Eventually all fallout will decay to a militarily
Four basic types of nuclear radiation are given
off during a nuclear explosion: alpha
particles, beta particles, gamma rays, and
Base surge from an underwater burst is a rapidly
expanding cloud or mist of water droplets. This cloud
is produced by the collapse of the water column that
was thrown up by the underwater detonation. After the
Which of the following factors is not
early, rapid expansion of the visible base surge (2 to 4
considered in determining if greater damage
minutes), the base surge moves downwind at the speed
to a ship will be caused by the direct wave or
of the surface wind. The base surge will become
the reflected wave from an underwater
initially will occupy about the same volume as the
Distance from burst
visible base surge. However, as the water droplets
evaporate, the radioactive particles and gases will
Depth of burst
remain in the air and continue to disperse as an
Depth of water
invisible radioactive base surge. For approximately 30
Height of wave action at time of burst
minutes after the burst, the base surge is highly
contaminated with fission products and is a source of
Initial nuclear radiation is defined as the
intense transit radiation.
radiation that is emitted by the fireball and the
cloud during the first minute after detonation.
enter a ship or shore installation through the ventilation
A nuclear burst can produce an atomic
ventilation ducts, boiler air passages, and interior
magnified pulse (AMP) that contains
spaces. High concentrations of radioactive material in
these trunks may produce a gamma-radiation hazard to
few to several hundred kilocycles per second.
personnel working nearby. Radioactive material
deposited in interior spaces may also present radiation
hazard to personnel coming into contact with beta
particles, even though there may be only a minor
penetrating gamma-radiation hazard. For aircraft in
flight, the entry of airborne radioactive materials will
not be a hazard during the flight but may represent a
hazard to maintenance personnel later.
Learning Objective: Recall the different types of
RADIOACTIVE WATER POOL
personnel injuries that are caused by blast, underwater
shock, thermal radiation, and nuclear radiation.
A surface or underwater nuclear detonation creates
Injuries to personnel can be caused by the blast, by
a radioactive water pool in the area of the detonation.
underwater shock, by thermal radiation, and by the
This pool expands outward rapidly from SZ, for about
2 minutes, and continues to expand more slowly. At 30
nuclear radiation produced by a nuclear burst.