ject has potentialities and should be reinstituted on a larger
scale for future tests.
D.
Results from Previous Operationz.
Due to the small number of surface shots detonated prior to
CASTLE, only a limited amount of data was available on the longrange fallout aspects of this type burst, and in particular, oniy
the close-in phenomena were available for the high yield type.
As
a consequence, although certain factors couid be reited on, in general only assumptions could be made in reference to these devices
prior to the operational pericd.
The CASTLE experience, however,
will be of inestimable value to radsafe planners in future opera=
tions.
.
For example, the CASTLE experience developed two important
areas of radiologizal study about
the Operaticn.
which little was known prior to
It had been predicted that significant fallout
would occur during the first twelve nours following the flring of
the device.
Past experience in this matter seemed to favor a six-
hour pericd for significant fallcut3 however, since the off-site
fallout aspects of MIKE 2hot cf Operatice IVY were mct known, tne
value of twelve hcurs was used as a margin of safety.
the! sHor/
and [sor2 experience revised this thinking somewrat for from the
action of these shots it became apparent that something on the ore
der of at least eighteen and possitly twenty-four hours would be
more realistic, especiaily for surface iand bursts,
As a conss-
quence, a new technique was developed to approximate the signifi-