TABLE 4.1 ACTIVITY PER UNIT AREA FOR SKIFF STATIONS, SHOT CHEROKEE No fallout was collected on the skiffa omitted from the table. Approximate Station Dip counts/min at H + hr AA TABLE 4.2 I. 3,094 196.6 2.5 x 10% 4,459 9,885 150.3 214.2 2.8 x 104 8.7 = 10! 5,720 858 8,783 452 196.2 196.1 214.0 432.0 4.6 6.9 7.7 8.0 BB 3,084 GG BH MM vv cc DD 196.6 Measurement Instrument Station location, ships —_ A-C Time of arrival TR Station location, skiffs Comments +500 to 1,000 yards, _ £1,000 yards. Uncertainty in first tray significantly above background; arrival uncertain within time interval tray exposed. Uncertain for initially low rates of field increase; malfunctions on skiffs; clockreading difficulties. _ Uncertain for protracted fallout duration and sharp deposition rate peaks. Depends on knowledge of decay rate of residual material. Arbitrary selection of significant increase above background. A-C Time of arrival Ic A-D Time of arrival TOAD A A-C Time of peak ionization rate Time of peak fallout arrival rate TIR Ic D Time of cessation TR B-D Time of cessation 1c Cc Tonization rate, in situ TIR Cc Cc N B Apparent ionization rate, in ocean Apparent ionization rate, in tank Tonization rate, above sea surface Ionization rate, in situ SIO-P SIO-D NYO-M T1B, Cutie Pie c N Total dose Total dose D D ‘ Weight of fallout/area Fraction of device/area (Fe, U) . Original coral-sea-water : , Rate plot for protracted fallout and fallout TR ESL film pack D Fiasions and fraction of device/area (Mo™) Fissions /area with sharp deposition-rate peaks may continue to end of exposure period; cumulative activity slope approaches 1. Poor directional-energy response (Appendix A.2); variations in calibration; poor interchamber agreement. Calibration variable, mechanical difficulties. Calibration variable, electrical difficulties. High self-contamination observed. Calibration for point source in calibration direction; readings ~ 20 percent low above extended sources. See above: Ionization rate, TIR. Assumed « 20 percent. occ Bias uncertainty (Section 4.3.2); variability occ of background collections; see below: Elemental composition, fallout. Bias uncertainty (Section 4.3.2); uncertainty of indicator abundance in device surround- inga; see below: Elemental composition, fallout. occ Variations in atoll, reef, and lagoon bottom constituents c x 10% x 10" x 1018 x 10° EVALUATION OF MEASUREMENT AND DATA RELIABILITY A D 2.5 x 10! Field Measurements and Deposition Properties Class A fiasions/t? composition; see below: Elemental compo- sition, fallout. Bias uncertainty (Section 4.3.2); device fission occ SIO-P, dip yield uncertainty. Uncertainties in dip to fission conversion factor, ocean backgrounds, fractionation of radionuclides, motion of water; see above: Apparent ionization rate, in ocean. 124