2.2.4 USS BAIROKO (CVE-I15) At approximately 0800 hours on | March, the BAIROKO began receiving heavy fallout from the Shot BRAVO cloud (Reference 10). Material Condition ABLE was set throughout the ship and all unnecessary personnel were ordered below. All ventilation was shut down to minimize contamination of spaces below the hangar deck. The ship's washdown system was activated at 0810 hours and remained on for approximately two hours, but failed to provide a sufficient volume of water to wash away the heavy fallout of contaminated coral sand (Reference 16). By this time average intensities on the flight deck were 500 mR/hr; intensities as high as 5 R/hr were measured in some of the cross deck gutters and a maximum reading of 25 R/hr was obtained from a flight deck drain. Fire hoses were broken out at approximately 1000 hours and used to wash down exposed areas for the remainder of the afternoon; by 1600 hours, average flight deck intensities had been reduced to approximately 200 mR/hr. é Another period of fallout consisting of very fine particles was encountered while enroute to Enewetak between approximately 1700 and 2400 hours, | March. Fire hoses were again used to wash down the flight deck, forecastle, fantail, and the bridge until approximately 1900 hours. At this time, topside intensities were still quite high (180 mR/hr), however, rad-safe personnel recommended sending all personnel who could be spared below decks because of the possibility of inhaling the extremely fine particles. No further decontamination was accomplished on | March (Reference 16). At 0800 hours on 2 March, a rad-safe survey indicated that average intensities on the flight deck were from 100-200 mR/hr. Decontamination efforts were carried out all day on 2 March and, by 2000 hours, intensity levels had been reduced to approximately 30 mR/hr (Reference 16). After two more days of decontaminating the flight deck and other exposed surfaces, average intensities of approximately 10-15 mR/hr were recorded on 4 March, when decontamination was considered complete (Reference 17). Figure 2 -11 depicts the average radiation intensity on the flight deck of the BAIROKO resulting from Shot BRAVO fallout. The effectiveness of the decontamination efforts on 2 March are clearly evident by the sharp decrease in the average intensity between approximately H+28 and H+34 hours. 51 Decontamination