be made.
Table 4 summarizes the fallout pattern characteristics fron
the Bikini tests.
The Tast column in most cases indicates that the
wind directions precluded fallout on the islands.
tions are Bravo and Yankee.
were in fact made.
The definite excep-
For Bravo and Yankee, off-site measurenents
None cf the Enewetak shots resulted in fallout on
3ikini or other islands to the east, so the test operations in Table ]
carn be ignored.
" Figure 2 shows the Marshall Islands relative to the test loce. tions.
The Bravo fallout pattern has been reconstructed independently
by AFSWP, NRDL and RAND using some modelling, while the Yankee pettern
is based on extensive Surveys.
. istands are given in Table 5.
The one-hour dose rates for affected
Al) of the listed islands are outside
the lowest dose-rate (1O0R/HR) contour for Yankee (Rongelap is just
barely); the levels are stated only to the nearest decade since
extrapolation had to be used.
The range of values for Ronge)ap anc
Rongerik 7s due te the variation of the Bravo pattern across the
respective island.
By and large, Bravo is the predominant contributor.
Table 6 provides 1977 estimates of the Cs 137 dose rate for
these islands.
On the basis of the limited comparison performed for
the Enewetak case, these values could be reduced by a factor of about
6 to account for soil migration, provided the geology is similar to that
| for Enewetak.
The final part of this paper is devoted to identifying with
‘high confidence which islands did not receive fallout from the Bikini
tests. Table 4, as discussed above, indicates that only Bravo and
_ Yankee definitely resulted in fallout on the islands; this is based
on the use of off-site measurements to reconstruct their respective
fallout patterns.
The other shots in the Castle operation, for which
there were no off-site measurements, apparently were not a problem.
However, a detailed investigation is warranted and is reported on in
the appendix.
Also contained there is an extrapolation of the Bravo
and Yankee patterns to a Jevel consistent with background.
emmy
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