SLIDE 13 Analysis of BRAVO fallout. Bikini Ash fell on the Japanese fishing vessel, the 5th Lucky Dragon, on the day of the test. Its gross beta activity was measured and standarized to day 26, and individual nuclide beta-activity was identified and quantified by Japanese scientists (Ya56, Ts55). The studies by Suito, Takiyama and Uyeda (Su56) indicated Bikini Ash consisted of irregularly shaped white granules. Bikini Ash, taken from the deck of the 5th Lucky Dragon, was deposited while the ship was located about 150 km (90 miles) from the detonation site (Ta55). From the size and shape distribution it was determined the mean volume diameter of Bikini Ash granules was 320 ym + 70 wm (Su56). The mean volume diameter was defined by them as the diameter corresponding to the mean volume. The mean mass of a granule was 0.039 mg (Su56). The specific gravity was 2.4 (Su56), less than the specific gravity of CaCoz, 2.7-2.9. The granules were aggregates of smaller unit particles with shapes that varied from spindles to cubes to spheres (Su56). The size of these smaller unit particles making up the granules varied from 0.1 to 3.0 wm (Su56). It was suggested by Suito that Bikini Ash was formed by evaporation of the coral reef to its constituent atoms and then by recrystallization of Ca with H0 and C05 in the air. ANALYSIS OF BRAVO FALLOUT CaO 55% MgO CO2 H20 7% 12% 26% Microscopic Detail of BRAVO Fallout 18