Page:Operation Crossroads 1946.pdf/124

 "In the laboratory, radioactive material was handled by remote controls. At Bikini, it was scattered over the decks of the ships. Men walked through it, tracked it around, and got it on their clothing and hands and faces. There was some tendency on the part of the men to disregard a danger which they could not see, nor touch, nor smell. It was known that the men could not taste the radioactive material. But they could eat it! The situation was fraught with grave danger if the enlisted men could not be trusted to do exactly as he was told. It became apparent that it would be necessary to subject these men to long periods of training before they could be expected to abide by the precautions which are commonplace in a nuclear laboratory."

On 4 September, Los Alamos reported by message an analysis of samples taken from target ships that showed measured levels of alpha contamination. The maximum alpha reading came from USS Skate (SS-305) periscope mast sample, reportedly taken on 19 July. This pre-BAKER test date conflicts with the DSM final report of late 1946, which states that no extensive deposits of alpha emitters were found following Test ABLE (Reference C.9.185, p. 3). This fact, plus additional circumstantial evidence, suggests that the date was a typographical error, and should have read 19 August (Reference C.13.12). The periscope mast sample read 1,830 alpha disintegrations (assumed to be disintegrations per minute per gram [dpm/gm]) and 9,100,000 beta disintegrations for a beta-to-alpha ratio of 5,000 to 1. Other Skate readings were: Bow -- 28 alpha dpm/gm, 93,400 dpm/gm, ratio 3,500

Frame 120 -- 0 alpha dpm/gm, beta 9,160 dpm/gm

Base of 5-inch gun -- 50 alpha dpm/gm, 115,000 beta dpm/gm, ratio 2,300.

Four samples from USS Wainwright (DD-419) collected on 18 August show alpha counts of 263 (beta-to-alpha ratio 3,500), 12 (ratio 2,500), and two zero alpha counts, but both of the latter with beta.

Three samples of unknown collection date, two from USS Searaven (SS-196) and one from USS Parche (SS-384), show alpha counts of 38 (beta-to-alpha ratio 1,400), 28 (beta-to-alpha ratio 66,000), and 23 (beta-to-alpha ratio 5,600) (Reference C.11.2).

A later analysis of 31 samples from 23 target ships all indicated the presence of alpha radiation. All but six of the samples had less than 10 dpm/cm². Nine of the samples were 1 dpm/cm² or less. The highest reading was a sample from USS LST-52, at 183 dpm/cm² and a beta-to-alpha ratio of 677. After Test BAKER, it was calculated that LST-52 received one of the highest radiation exposures from deposition of material in the rainout and base surge (Reference C.11.28).

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