2.2.3 USS APACHE (ATF-67) The APACHE encountered fallout after three of the CASTLE detonations. During the early afternoon of 1 March, while operating in an area southeast of the BRAVO GZ, the (Reference 10). APACHE began receiving fallout at approximately 1300 hours The ship's washdown system was turned on several times during the day, which helped to reduce intensities somewhat, but it was not until early in the morning on 2 March whenintensities leveled off at approximately 30 mR/hr and then began to decay. Figure 2-9 depicts the average topside radiation levels on the APACHE as derived from shipboard measurements taken through 0800 hours, 8 March (Reference 10). Approximately nine hours after Shot ROMEO, the APACHE began receiving a relatively light fallout while operating in an area southwest of the ROMEO GZ. At 1600 hours, when average intensities had reached 20 mR/hr, the washdown system was turned on for an hour which quickly reduced intensities to approximately 1 mR/hr (see Figure 2-10). No further fallout was encountered by the APACHE on 27 March. During the late afternoon and evening of 28 March, while enroute to Enewetak, the APACHE again encountered fallout from Shot ROMEO. A peak intensity of 42 mR/hr was recorded at 1600 hours (Figure 2-10), but it was not until early in the morning on 29 March, while anchored at Enewetak, that intensities were reduced below 20 mR/hr. The same fallout encountered by the APACHE while east of Enewetak eventually drifted westward resulting in fallout on Enewetak. Figure 2-4 shows a very similar fallout "pattern" as that received by the APACHE except that its time of arrival was delayed somewhat and maximum intensity levels had decayed accordingly. - The APACHE wasanchored at Kwajalein when Shot YANKEE fallout occurred on that atoll. It is assumed that, while at anchor, the ship received the same fallout as Kwajalein (See Figure 2-8). None of the other shots in the CASTLE series resulted in shipboard contamination on the APACHE. The APACHE entered the contaminated waters of Bikini Lagoon eight times during the operation; dates and times are detailed below. 46 Based on the ship