be made.
Table 4 summarizes the fallout pattern characteristics fro:
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
Wone cf the Enewetak shots resulted in fallout on
Bikini or other islancs to the east, so the test operations in Table 1
can 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 pattern
is based on extensive surveys.
_ dstands are given in Table 5.
The one-hour dose rates for affected
All of the listed islands are outside
the lowest dose-rate (100R/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 Rongelap anc
Rongerik is 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 ¢s3? 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 thet
: for Enewetak.
.
_,_.,, DOE ARCHIVES
7
The final part of this paper is devoted to identifying with
" high confidence which fslands 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 fs 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 level consistent with background.
32