intensities of 0.6 mR/hr. The next survey, at noon on 4 March, indicated a slight drop in intensities to 0.5 mR/hr; an aerial survey on 19 March indicated a further reduction to 0.1 mR/hr. from Figure 2-6 depicts the radiation environment on Kwajalein resulting Shot BRAVO as inferred from the survey data. The 4 March intensity of 0.5 mR/hr has been extrapolated back to 2000 hours, 2 March, using the decay exponents derived from the Bikini fallout data (Section 2.2). This indicates that the fallout on Kwajalein probably did not peak until shortly after the survey conducted at 1800 hours on 2 March. The 19 March intensity derived from the aerial survey data appears somewhat higher than would be expected if the 4 March intensity is extra- polated forward with time using the Bikini decav data. Much moresignificance is attached to actual ground readings, when available, than to ground intensities derived from aerial survey data. Secondary fallout from Shot ROMEO did not arrive at Kwajalein until 3 days after the detonation. A ground survey on Kwajalein at 1545 hours, 30 March, indicated an intensity of 0.05 mR/hr, approximately twice the Shot BRAVO background at that time. Subsequent surveys on 31 March revealed intensities of 1-3 mR/hr. Aerial surveys on 3, 8, and 12 April establish a rate of decay for the ROMEO fallout that is proportional to rl, a ground survey reading of 0.1 mR/hr on | May supports the decay rate established from the aerial surveys. Figure 2-7 depicts the total fallout on Kwajalein following Shot ROMEOand the individual contributions from Shots BRAVO and ROMEO, Minor fallout also occurred on Kwajalein approximately one day after Shot YANKEE. Surveys conducted during the afternoon of 6 May indicated maximum ground intensities of 1.0 mR/hr. Average intensities of 0.4 mR/hr were derived from aerial surveys. Subsequent aerial surveys on 8, 15, and 16 May revealed that YANKEE fallout also decayed approximately propértional to tt . Figure 2-8 shows the YANKEE fallout on Kwajalein as derived from the aerial and ground survey data. Also shown are the contributions from BRAVO and ROMEOfallout to the total. The intensity curves defining the radiation environment on Kwajalein during Operation CASTLE are time integrated, by day, through 31 May. free-field intensities are summed and tabulated in Table 2-2. 41 Daily integrated