Appendix - Assessment of Wind Profiles and Fallout Patterns for Bikini Tests

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PATTERNS FOR BIKINI TESTS The Bravo and Yankee shots, as previously discussed, both deposited fallout on the islands east-of Bikini, In both casesi the lowest reported contour leve? was not low enough to circumscribe the total fallout deposition, Extrapolation was used to define the 0.1 I{/}Iii(H+]) contour; this level was chosen because it results in ariexposure the first year of about 200 rnreni,whichis about the annuel background dose. . Shown in Figure 2 is the southern periphery of the Bravo and Y~nkee patterns relative to the location of the islands. 6 The other Castle shots are Romeo, Koon and Union; off-site fallout measurements are not available so that their respective wind profiles have to be examined. The Romeo winds at H+3 and H+9 (DASA 1251) were not measured above 67,000 ft. B~~ow this altitude the dominant djre~tion of the profile is to the north; while not measured for the test, ‘the higher altitude winds are uniformly to the west. Thus it is safe to state that the Romeo fallout did not reach any of the off-site Marshall Islands. Shot Koon winds were documented for all levels of interest. Except for near.surface, no winds had a northerly component that would have carried any fallout to the south and east. It can be stated tith high confidence that Koon fallout carried to the north and east, and did not reach any of the Marshall Islands. Shot Union presented a rather unique wind problem. Although the lower altftude winds were from the east, strong northerly an’d westerly components existed from 12,000 to 5u,000 feet. The influence of the winds is not readily apparent without further examination. Therefore a crude reconstruction of the fallout pattern was performed by determining the displacement of 50, 100 and 2001 particles which are initially assumed to be at cloud top and at cloud bottom. This permits the construction of an envelope of all such particles in the

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cloud. The H+6wind profile was used and constant fall rates of .15, .57 and 2.1 m/sec,respectively,were used for the three particle sizes. (Including the altitude dependence of fall rate is probably~n over- . Specifi cation,consideri ng the uncertainty in the spatial variatior, of the wind). ~ Shown in Figure 3 is this envelope. Taongi is definitely . . affected by the Union fallou~ but the other islands are outside the