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 to make them aware of the discussion in progress, to summarize safety precautions, and to give information on the clearance procedure under development (Reference C.9.185, pp. 125 and 145). His letter, however, did not (Reference C.9.185, pp. 25 and 26):


 * 1. Establish adequate decontamination procedures or a plan for developing them


 * 2. Establish the final tolerance level for alpha emitters, the alleged principal hazard


 * 3. Assign responsibility for decontamination and final clearance.

During the next several months the Navy put considerable effort into filling these gaps.

ComWestSeaFron on 11 September recommended to CNO that highest priority be given to providing staff for the JTF 1 Medical Officer, that BuShips have the responsibility for developing decontamination methods, and that the DSM be dispatched to the west coast as BuShips' representative. On 13 September CNO advised that ComWestSeaFron and BuShips had been assigned the responsibility and that the DSM was on his way, to arrive on 17 September (Reference C.9.185, pp. 26 and 27).

Decontamination Experiments at San Francisco Naval Shipyard

Meanwhile, efforts to measure contamination continued. On 12, 13, and 19 September portions of Laffey's hull were sandblasted and particle samples collected in filter devices set up nearby. A section of contaminated saltwater pipe was burned through in a small, closed compartment and particulate samples collected in a filter device (Reference C.9.185, p. 29). The samples were taken to the University of California Crocker Radiation Laboratory for analysis.

Methods for learning contaminated saltwater lines were tested. On 13 and 17 September various acid solutions were pumped into sections of Laffey's saltwater plumbing and then the sections were flushed a number of times. The result was a considerable reduction in radiation levels. These experiments were judged completely successful. Also on 17 September preparations were made to test acid solutions on the saltwater plumbing of a second ship, Henrico (Reference C.9.185, pp. 30 and 32).

The DSM arrived on 17 September, and during the next few days, he conferred with officials supervising contamination measurement and decontamination experiments. He inspected the work being done on Laffey and USS Benevolence (AH-13) (Reference C.9.185, pp. 30 through 33).

On 20 September, laboratory assays of rust, evaporator and condenser scale, saltwater lines, algae from the hull, and other samples from Laffey, Kenneth Whiting, Henrico, and Mount McKinley were completed. They indicated that the amount of plutonium (an alpha emitter) associated with fission products (beta and gamma emitters) was quite constant. Thus - the plutonium concentration - could therefore be estimated from the fission product activity with a Geiger counter (Reference C.11.17).

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