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Figure 38. Inspection of USS Hughes (DD-410) at Puget Sound Naval Shipyard in 1948 showing workers wearing protective shoe covers and gloves.

concentrations of radioactive contamination were observed in the marine growth and rust on their hull exteriors at the waterline. Even though the water in which the ships were anchored showed a radiation intensity of only about 0.01 R/24 hours, the radioactivity collected on the hulls to such an extent that several ships had interior readings in the vicinity of the waterline exceeding 0.1 R/24 hours (Reference C.9.185, p. 18).

Decontamination at Bikini

On 29 July, faced with increasing radioactivity in the water where the ships were anchored and hoping to deal with problems of contamination, the support ships and the target ships that had been cleared as radiologically safe were moved to a new anchorage in the southeast portion of the lagoon (Reference C.9.185, p. 19; Reference A.2, p. 101). All ships were ordered to list ship, that is, change ballast, causing them to list and expose portions of their hulls below the waterline for scraping (Reference C.9.185, p. 19). Rather than immerse themselves in the lagoon water, personnel were to use long-handled scrapers (Reference C.10.7). Because the ships' evaporators used to distill freshwater concentrated radiation from the lagoon water in the scale on the inner surfaces of their shells and tubing, radiation levels near some of them exceeded the 0.1 R/24 hours limit.

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