Upon arrival at Kwajalein Atoll, the personnel evacuated from Rongerik were monitored for personal contamination and decontaminated. The decontamination program, consisting of repeated showers and radiation monitoring, continued from 2 March through 6 March. While at Kwajalein, the film badges that had originally been issued to the Rongerik detachment were collected and processed. In addition, urine samples, both pooled and individual, were collected and sent to laboratories in the United States for analysis. Late in April, the servicemen from Rongerik were transferred from Kwajalein to Tripler Army Hospital (Honolulu, Hawaii) for further observation and subsequent return to duty (References 3, 4). 2.2. AVAILABLE DATA AND ASSUMPTIONS Just prior to the first evacuation on 2 March, a gamma intensity reading was obtained with an uncalibrated AN/PDR-39 radiation survey meter. Because the operating condition of the instrument was not known at the time of its use, this reading (2000 mR/hr @ H+28.5 hours--Reference 5) is used only to indicate the general magnitude of the fallout intensity at the time of the first evacuation. The first radiological survey with calibrated instruments on the atoll was conducted on 10 March 1954, nine days after the shot. At this time the rad-safe survey team encountered average radiation intensity readings of 280 mR/hr on the island where the military personnel had beenstationed. The only other radiation intensity data available from Rongerik were obtained on 1 March when a low-level gamma background monitoring instrument at the weather station began to register at 1407 hours and then went off scale (100 mR/hr) at 1437 (H+7.9 hr). The data from this instrument establish the time of arrival of the fallout. After Shot Bravo, analyses of fallout samples were made to determine the decay of gamma intensity with time. Unfortunately, the only data complete enough to be utilized were from Bikini Atoll and may not be completely representative of the fallout decay on Rongerik Atoll. Radiation intensity readings obtained from the Bikini lagoon (How Island) indicated decay rates that varied considerably from the traditional yl? rule. Average values for the decay exponent, obtained with several gamma ionization time-intensity meters on Bikini (Reference 6), are as follows: