stot, Flathead, much of the fallout ren.ains airborne. be expected to persist well into D: 1. 3.3.6 Shot Tewa. Thus, fallout and mixing im the si could A D-—1 survey (Figure 3.20) defined the background status to the west of theatoll, prior to the shot. The D-day flight (Figure 3.21) located the upwind bounJary. The TABLE 35 SUMMARY OF FALLOUT DISTRIBUTION, ae Isodose mr/hr Area mi? _ Difference Area Tae NAVAJO cae ag Average mr/hr | [ | D-1 : 1.25 0.25 \ 158 958 158 800 1.35 0.75 \ 0.125 1,788 830 0.18 ) 0.025 10,490* 8,702 0.06 ' i D+2 1.25 0.25 0.125 0.025 90 1,267 3,263 20,930* 90 1.35 1,177 1,996 17,667 0.75 0.18 0.06 ‘ ve ee . v -s * Based on estimate of isodose position. D +1 survey (Figure 3.22) discovered a contaminated area extending over 200 miles west of Bikini. The outside boundary could not be closed on this survey, because of the far-out sector contained active fallout from Shot Huron. The D+2 survey (Figure 3.23) extended the estimated position of the EOB- The isodose was still not completely closed. The aircraft was not allowed to lose radio contact, so the survey covered only the area out to 275 miles from Bikini. The 0.25 mr/hr sodose extended into the far northwest sector on D+1. By D+2, the position had shrunk to apprc<imately a third of the enclosed area. The predicted pattern shows that this far-out material could not be expected to arrive before H+19 hours. Thus, it is probable that the readings in the area on D+1 were due to material that was not completely mixed. By D+2, some 30 hours had >lapsed, and mixing was probably complete. The D+3 and D- 4 surveys, Figures 3.24 and 3.25, delineated the hot area, permitting an examination of the shape and position of these inner areas from D+1 through D+4. summarizes the fallout areas throughout the shot participation. Table 3.6 3.4 SAMPLES OF CONTAMINATED SEA WATER Duplicate samples of sea water were furnished to this project by the U.S. Naval Radiological Defense Laboratory (NRDL) and by Scripps Institution of Oceanography (SIO) fromtheir seasampling programs. After the close of Operation Redwing, these samples were analyzed for beta activity in the particulate and salt fractions at the HASL. 3.4.1 Gamma Radiation as a Function of Beta Activity. The analysis of each sample, the ganima intensity estimated at each sampling location, and the comparison of these results are contained in Appendix D. A straight averaging of the beta activity and the estimated gammaintensity ylelds a figure of 4 x 10°(dis/min)/liter per mr/hr. The wide variability of the comparison for each sample obviates definite conclusions. However, much of the data falls within + 50 percent of the theoretical calculation of 4.43 x 10°(dis/min)/liter of beta activity per mr/hr of gamma activity 3 feet above the surface. Thus, these results may be considered indicative of validity of the assumption. 45