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AIRBORNE PARTICLE STUDIES.
Cperation BUSTER-JANGLE.
Charles Robbins, Hugh R. Lehman, David R. Powers, and
James D, Wilcox, July 1952.
SECRET-RESTRICTED DATA
a: The airborne-particle studies reported here were undertaken by
the Chemical Corps to supply data on the internal hazard due to radio-
active particulate matter associated with the cloud and on the base-surge
produced by surface and underground detonation of atomic weapons.
The highest sampled concentrations of radioactive materials in the
near-ground dust clouds appeared to be about 1073 and 107lye of beta activity
per cubic centimeter of air, for the surface and underground detonations
respectively.
These concentrations were found at downwind distances of
about 2,000 to 4,000 ft, the concentrations falling off rapidly crosswind,
and at greater downwind distances.
These concentration values apply to
an exposure averaged over the approximate interval between arrival and
departure of the cloud, and with beta activity corrected at the average
time of exposure.
The number-median diameters of the particles in the aerosols were
1.0 yp and 1.5 yw for the surface and underground shots, respectively, at
stations 4,000 ft downwind. These values decreased to less than 0.1 yp for
both shots at 50,000 ft downwind.
WT-400
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DECONTAMINATION OF PAVED AREAS.
Operation BUSTER-JANGLE, (Chapter 5).
J. C. Maloney, June 1952.
SECRET-RESTRICTED DATA
ue Sections of paved roadway located 2,000 ft to 1 mi from surface
and underground atomic~-bomb detonations were decontaminated by eight
different procedures: dry sweeping, vacuum cleaning, air-hosing, water-
sprinkling, -low-pressure hosing, high-pressure hosing, wet sweeping, and
air-and-waver hosing.
A uniform grid was marked off on each test surface,
and readings were taken before and after each decontamination process.
Beta-activity readings were taken on the surface, at the center of each
grid square; and gamma readings at heights of 3 and 6 ft above these
locations.
Some of the wide disparity between the readings obtained
following the surface and underground shots may be accounted for by a
heavy rair and high wind that followed the surface shot closely, removing
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practically all loose contamination from the test surface.
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