CHAPTER 2
OPERATIONS
Fallout of military significance zenerally is characterized in
this report as that material which arrives at r.tatively early times
and forms a well-delineated pattern in which the radiation intensity is
high enough to affect the conduct of a military mission.* This has
been designated "primary" fallout to distinguish it from continent- and
world-wide ("secondary")
fallout.
From IVY it was concluded that "the
areas of primary fallout particularly from super-weapons, are quite
extensive, and many hours can elapse before the fallout gamma field is
completely defined."//
The present operations were directed toward documeats tion of the
primary fallout, with investigations of secondary fallout included only
whers they contribute to the former, Operation plans were made on the
following assumptions:
a
adherence to a reasonably firm shot schedule
(>)
availability of adequate losistic support to make
(c)
scaling of the faliout pattern by the cube root lav,
necessary collections
Unavoidable circumstances, the most significant of which prevented the
firm shot schedule required by these plans, caused much of the work to
be dene under less favorable programming devised in the field.
2,1
EXPERIMENT DESIGN
Since the fallout from the CASTLE series was deposited largely
over ocean areas, the experiment design required methods of documentition
that permitted estimation of what the radiation field would have been
had it fallen on land, The estimtion was accomplished by: (1) estublishing a ratio between the fallout collected per unit area over land,
* A quantitative definition of the term “military significance” or
"military importance" depends entirely on the situation existing when the
term is applied. Such factors as the target affected, che distance from
ground zero, and the arrival time of ths debris ag well as the exter+ of
its fallout pattern must all be considered, The lower limit below which
no combination of circumstances will create a levelof military signifi-
cance may be taken as 5 r/hr at 1 hr.