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Test results indicated that complete protection from an
atomic explosion is afforded both personnel and equipment in a4 protected
shelter installation of the type described.
No functional damage to the
shelter or to any of the installed quipment resulted from the blast.
Increases of pressure and temperature within the shelter, due to the blast,
were negligible. The antiblast closures functioned adequately in dampening
the blast, in protecting the particulate filter-units from sandblast damage,
and in preventing a hazardous pressure buildup within the structure.
Protected-side pressures of not more than 12.6 lb/sq in.were measured in
field instalZations located from 300 to 2,500 yd from ground zero.
The
indicated radiation level within the shelter closely approximated that
which would be expected from direct radiation alone.
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CLOUD PHENOMENA:
STUDY OF GASEOUS AND PARTICULATE MATTER.
Operation GREENHOUSE.
Elmer H. Engquist and Thomas C. Goodale, October 1951.
SECRET-RESTRICTED DATA
Samrles gathered from atomic clouds indicated that the radiochemical composition of cloud particles yaries with their size.
Specific
radioactivity was found to vary considerably in the particle size range
of 0.1 p to 27 pp.
The ratio of inactive to active particles in a cloud
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was found to vary between 100:1 and 1300:1, depending on the specific
shot.
The ratio also varied due to the method of collection by different
aerosol sampling devices.
The Secay rate of the cloud particulate matter varied with
particle size; the decay exponent, n, ranging from 1.05 to 1.25 during
the period 2 =o 40 days after detonation.
The concentration of
particulate beta activity in the cloud varied inversely with the size of
the bomb.
+a energy of the cloud contaminant ranged from 0.36 to
0.59 Mev; gamma energy ranged from 0.6 to 1.0 Mev.
Electrostaticprecipitator samples indicated that 1.1 to 1.3 beta particles were emitted
per gamma ray.
Differing results were obtained when calculating the concentration
of beta activity in samples collected by the electrostatic precipitator
and by the cascade impactor, at H + 10 seconds after each of 3 shots.
Electro-static-precipitator samples were calculated to range between
2.9 and 17.5 c/ee.
Corresponding values for the impactor samples were
between 0.75 end 4.0 uc/ec.
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