Program 2, ..uclear Radiation and Effects
Program 2 {Included ten projects, which could be grouped into four categories: (1) underwater detonations, (2) high altitude detonations, (3) developmental shots, and (4) nuclear radiation from
device of par~
ticular interest to the Army, (discussed under
ce and Fig Results).
Underwater Shots, Wahoo and Umbrella
Shipboard Radiation Vulnerability. It was the object of this study to
document the gamma radiation phenomena generated aboard three target destroyers by shots Wahoo and Umbrella. Both total gamma dose and gamma
dose rate histories were measured by film badge dosimetry and gamma in-
tensity time recorders (GITR's), respectively. Unshielded GITR stations and
film badges supplied data on radiation at locations representing major battle
stations; underwater GITR instrumentation supplied data on radiation in the
water; and directionally shielded GITR stations mounted on deck supplied information on radiation from remote sources.
Radiation histories were obtained on only one destroyer during shot
Wahoo because of ship's power failures on the two other destroyers. Radiation histories were obtained on all three ships during shot Umbrella, although —
some data were lost because of shock damage. Preliminary results indicate that weather-deck dose buildup ranged between 600 r received within 0.5 min
at 2,000 ft from surface zero and 45 r received within 2 min at 8,000 ft.
Dose reductions by factors leas than 6 were obtained for all compartments
above the waterline, and dose reduction factors greater than 9 were obtained
only in machinery spaces below the waterline. Transit radiation appeared to
represent a high percentage of the total radiation observed aboard the ships.
In the one case where data were obtained, the underwater radiation did not
contribute to the total radiation measured aboard ship. Data on gamma i{onization decay was obtained for the perlod from 0.1 to 34.8 hr after Umbrella.
Shipboard Contamination Ingress. This was a study of the external and
internal radiation hazards existing within typical {nterior compartments of a
destroyer-type vessel as the result of the ingreas of contaminant from nearby underwater nuclear detonations. Four compartments of the DD-592 were
instrumented with total and time-incremental air samplers, surface samplers,
animals (mice and guinea pigs), and GITR's. Rates of air flow for ventilation and boiler combustion for the instrumented compartments were controlled
50 as to be representative of those expected under nuclear-attack conditions.
Due to the failure of ship's power on the DD-592 during shot Wahoo,
only surface sampler and animal data were obtained. The failure of a project timing circuit during shot Umbrella resulted in logs of time-dependent
air sampler data although total air samples were obtained.
~
Estimates of the internal dose due to Inhalation in the test compartments
during Wahoo indicated that the doses were below the threshold for acute ex-
posure but that possible chronic effects might be produced.
Similar estimates
for Umbrella indicated that doses were below the threshold for chronic effects,
with the possible exception of the internal dose received in the engine room.
Umbrella estimates of the external dose rates in the test compartments
due to ingress of contaminants showed them to be a small fraction of the
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