anor sidered to be in a reasonably safe position since the personnel vere able to get into a well protected area deep in the bunker, reading approximately 35 or/r. The cloud tracking (by WB-29, Wilson 2) during the morning of B Day indicated no contamination of consequence moving toward Eniwetak or Ujelang at ten thousand feet. The afternoon upwind mission for Wile gon 2 was a 30 degree sector cut to 500 NM centered on true bearing of 70° from GZ. During the upwind portion of the cloud tracker's mission, readings were from 100 to 500 ur/br at ten thousand feet. During the morning ‘the B Day P2V sweep in front of the clond encountered contamin=ation early in kis mission. This PZ2V was replaced by another, which completed the search out to 600 NM. A report was received about 1500 on B Day that the ABC/NYOO instrue s™N. "., ‘ment in the bands of the weather detachzent on Rongerik had gone off scale. These instruments had a full scale reading of 100 ur/hr. The off-scele report was not viewed with concern since task force ships were experiencing readings (while steaming south) of more than 100 ar/ br (The BATROKO going as high as 1.0 r/br on the flight deck). Con sidering the distance (133 NM) and a clond tracker at about 1945M, 1 March, reporting of zero contamination over Rongerik, it was generally believed that Rongerik and the task force ships were caught in a gene~ ral pattern of finely divided (95% less than 5 micron by cascade im -_ pactor) particles over a wide area moving ENE to EB. The weather de tachment was advised of this condition. Nevertheless, the A&C/BYOO Ewejalein Flight ABLE was requested at midnight to be run the following mrning, Kwajalein Flight ABLE pattern covers all Marshall Islanis north of Kwajalein, and up to Taongi as the northern-most turning point. Serial readings taken on the flight are extrapolated to the grount. About 2000 the task force commander was briefed on the overall sit- uation as was known at this time. This included the results of sone im 4tial damage and radsafe survey information taken about noon by helicop~ ter, reports from the sampling aircraft (F-84, B-36 Featherweights end B-36 Control), the first twelve hour cloud tracking mission (Filson 2) ani the first few reports on the BY12 to 524 hour cloud tracker (Filson 3). The upwind mission for Filson 3 was a 30 degree sector out to 500 KY centered on true bearing of 65 degrees from Rongerik, followed by a vectored mission to 17N 163E to base st Eniwetok. The task force com co menier was advised that fairly heavy contamination bad been encountered by Wilson 2 in the sector portion of kis flight and that one F2vV aire ereft had been contaminated in about the same region. The task force commander was edvised that the readings taken at ten thousand feet by the cloud trackers were thought to be on the order of magnitude of that encountered by the task force ships. Since the only significant com

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