“Nel
possibility that these bombs might
have different energies and he
explosion should be undertaken
soon after the detonation for the
guidance of fire fighters and rescue teams. Subsequentiy, more de-
Protection Requires Planning
Adequate protection against the
effects of an atomic bomb attack
would require comprehensive and
detailed planning. Such planning
would be necessary to avoid panic,
for mass hysteria could convert a
minor incident into a major disaster,
The purpose of the Government
handbook, “Tne Effects of Atomic
Weapons,” is to provide the essential scientific and technical information that would permit necessary plans to be made for dealing
with the new and unusual situations that would arise as the result of the explosion of an atomic
bomb,
The organization,
preparation
and techniques designed to deal
with these situations involve considerations
beyond
the
book’s
scope. Their precise nature depends on many factors thet must
be evaluated nationally, and their
application would vary with the
patterns of regional and community development.
Any planning and organization
against a possible atomic attack
must be designed to meet the vari-
ous
destructive
effects
that
an
atomic explosion is likely to produce. These, as we have seen, include damage caused by air blast,
ground and water shock, thermal!
radiation,
essential
points
are
protection
from direct exposure for human
beings and the avoidance of easily
combustible materials, especially
near windows.
The only known defense against
the gamma rays and neutrons constituting the initial nuclear radiation is the interposition of a suffictent mass of material between the
individual and the atomic bomb,
including the rising Bali of Fire.
The use of concrete as a construction material, which is necessary
to reduce air-blast and ground
shock damage, would, to a great
extent, decrease the initial radiation hazard.
From the standpoint of physical
damage, the problems of construction and protection from atomic
bombs are not fundamentally dif-
ferent from those associated with
bombs of the conventional type. It
should not be forgotten, however,
that atomic bombs are enormous-
ly more powerful.
The damage
would cover an extensiVe area.
probably
several
square
miles.
These facts are important in planning for control of fire-fighting
and rescue operations.
Protection from the effects of
radioactive contamination presents
a problem that has not previously
been encountered.
The results of
initia) nuclear radiablast and fire are visible and can
tions, and residual nuclear radiagenerally be controlled in a relations. In addition, extensive fires
tively short period after an explofrom
Various secondary causes
sion.
But nuclear radiation canwould follow an atomic explosion.
not be detected by the senses withFortunately,
protection
from
out the use of instruments, and,
these hazards, although by no
unless the contamination is remeans simple, is not as complex as
moved, the deleterious effects may
the existence of so many danger
continue for weeks. months or
factors would imply.
In general,
longer.
it appears that proper protection
Even though the dangers from
against blast, shock and fire dam- | radioactivity after an atomic exage could also minimize the danplosion are uncertain and perhaps
ger to personnel frem thermal raexaggerated, nevertheless
some
diation and initial nuclear radiaconsideration must be given to
tions.
possible contamination of areas,
Thermal Radiation
structures and equipment.
As far as burning caused by
Monitoring of regions close to,
and especially downwind from, the
thermal radiation is concerned, the
detonated at different heights.
On the other hand, there is some
tailed monitoring may be required
to find which areas are safe for
justification for the choice of half
a mile from ground Zero, from @
Many steps can be taken to re-
lent) atomic bomb, as the point
from which protection should be
considered.
In the first place, the evidence
nominal (20 kiloton TNT equiva-
occupation,
duce both the personal casualties
and the physical damageeffects of
an atomic explosion. The planning
of new construction affords the
best opportunity for the inclusion
of protective measures at a mini-
from the Japanese bombings indieated that within this distance the
chances
of
survival,
from
one
cause or ancther, were very poor.
It is only beyond 3,000 feet or so
mum cost. But existing structures
can, in many cases, be strengththat the proportion of m"ersons
ened to make them more resistant
killed begins to fall off at an apto blast, fire and radiation, thus
preciable
rate. Suitable protective
increasing the protection afforded
| measures would result in an even
to personne! and equipment.
For example, blast damage can
sharper drop.
be reduced by strengthening strucNo Closer Protection
tures, particularly against lateral
Further, protection against blast,
and downward forces. It is desirinitial radiation, and thermal raable to keep to a minimum fixtures,
diation becomes practical at a half
ornamental plaster, or other intemile from ground zero, while at
rior treatments that might be discloser distances it would not genlodged when the buildings are
erally be feasible. In certain cases,
subjected to violent forces.
however,
stronger
construction
The fire hazard may be decreased
may be desirable on the ground of
by avoidance of exposed inflam' the essential nature of the operamable material. General protection
tions carried out in 4 particular
against gamma radiation may be
building.
achieved by a sufficient thickness
One of the most important lesof structural material.
sons learned from the atomic bomb
Question of Distance
attacks on Japan is the necessity
for the provision of an adequate
In taking protective measures,
how far away mayit be supposed
water supply for the control of
to supply a definite answer. but a
decision must be made on the dis-
was only thirty pounds per square
inch at the time of the explosion
fires.
In Nagasaki the water pressure
that the atomic explosion will
oecur? Of course, it is impossible
and
tance from the explosion at whic"
protection
becomes
because of
breaks
in
mains
and house service line; it soon
dropped to ten pounds per square
inch. On the following day the
practical.
Steps can then be taken to provide
protection appropriate to this dis-
pressure was almost zero, This
drop in the water pressure contributed greatly to the extensive desideration it seems that a distance
struction caused byfire.
of about half a mile from ground
The experience at Hiroshima
zero would be a reasonable comwas similiar.
promise for the planning of general protective measures. The asA large proportion of the fire
sumption is made that the bomb is
devastation in Japan after the
exploded in the air at Such 4
atomic bomb attacKs was because
height as would provide maximum
the fire-fighting services were incapacitated. It would seem to be
physical damage.
advisable that fire departments of
It must be admitted, however.
strategic
cities
and
industrial
that the choice of distance involves
an element of risk. for there may : plants should be housed in ctructures capable of withstanding the
be accidental or deliberate bursts
blast at about half a mile from the
of several bombs in proximity at
explosion. Underground constructhe same time. Further, there is the
tance.
Taking various factors into con-
43