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se et
JANUARY—DECEMBER 1963
211
research and high explosive exepriments conducted by the U.S. Army
Corps of Engineers’ Nuclear Cratering Group and the Lawrence
Radiation Laboratory (LRL), Livermore.
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wT 12
Fallout Patterns. The above drawings show, from left to right, the reduction
in radioactivity released from crater forming nuclear detonations as the fission
yield of the thermonuclear device is reduced. The pattern on the left (a) is
similar to that for Project Sedan of the Plowshare program, in which a 100kiloton thermonuclear device with less than 30 kilotons of fission yield was
detonated during July 1962. As a result of development of devices with less
fission yield, and through the use of special emplacement techniques, it is believed
that, at the present time, the amount of radioactivity released could be reduced
to the levels indicated in pattern (b). Work is underway on device development
and emplacement techniques to reduce the radioactivity released to the levels
shown in pattern (c) which would be about a 100-fold reduction of that actually
released by Sedan. These typical fallout patterns indicate the radiation dose
a person living outdoors at a particular location for a lifetime could receive.
In actual field operations, however, entry into such areas covered by these
patterns are controlled so that the population does not receive unnecessary
exposure.
Theoretical Understanding of Cratering
The basis for increased theoretical understanding is work conducted
in cratering physics at LRL using primarily data from the Sedan and
Danny Boy projects, and the pre-Buggy high explosive experiments.