ao. 17.5.3 Weapons-Test Data for Shielded Locations 1. Water Surface Bursts Qperation Castle: Interior-location dose rates were not recorded“ for shot 4. At shot 5 (Yankee), some transit radiation was received but not separately recorded” at unshielded locations on the YAG-39. Since washdown was operating, some (but not all) of the deposit radioactivity was washed off the ship, and thus the dose rates and doses recorded?[at various interior locations on the ship were considered partly (but not entirely) due to transit radiation. Peak dose rates, which occurred at about H + 5 hr, were about 1 r/hr in the interior of the superstructure, 0.4 r/hr in the bottom of No. 2 Hola, and 0.02 r/hr in the starboard boiler. The respective total doses to 12 hr were about 7.5, 3, and 0.15 r. Operation Redwing: As stated in 17.52, the only unshielded transit-radiation data at .his operation are those fox Shot Tewa; thus Tewa is the only shot for which a comparison of shielded and unshielded transit radiation would be possible. Although the dose rates at var- ious interior Jecations were recorded, the transit and deposit contrib- utione were not separated, nor are records for interior locations explicitly presented. Reference 41 gives ratios of interior dose rates and doses to total dose rates and doses recorded at the same times on the weather decks of the target ships. Such ratios are, in general, lese than 0.5. 2. Underwater Bursts Operation Crossroads, Shot Baker: Although film badgee recorded total gamma exposure doses in many shielded locations, the transit com- ponent of these doses is not known. Reference 29 estimated that on the weather deck, the transit component was about 50%, but at interior locations, the same reference states that details of badge placement varied, resulting "in wide variation of doses received by badges sub- jected to approximately the same radiation.” Also, according to this report, conversion of film density to radiation dose “may be in error as much as a factor of two," and the influence of shielding on the badge readings is apparently many times the shielding effect which might be expected from consideration of the plating thickness interposed between the badge and the exterior of the vessel." Thus, it is impossible to reliably estimate the transit component of the radiation records at “interior locations at Shot Crossroads Baker. ration Hardtack: Radiation histories were obtained on one ship at Shot Wahoo and on all three ships at Shot Umbrells. doses were also recorded. Film-pack It is estimated that transit radiation was responsible for 95% and 98% of the total doses recorded in shielded BEST AVAILABLE COPY 17-38