Decay data of a Shot 1 size graded sample are presented in Table 3.3 from work done by Project 26b.12/ The rate of decay of all fractions is the same for all but one fraction at times from 5 to 30 days after the shot. The absolute value of the decay exponsnt de- creased at later times but the smaller fractions exhibited relatively higher rates of ddcay. 3302 Shot 2 The Shot 2 decay=curve slopes,as plotted on log-log paper, increased with time when the time scale was based upon Shot 2. This phenomenon is unlike fission decay either with or without uraniun capture productse The curves as plotted on a Shot 1 zero-tims scale appear to be normal fission decay. The activity collected during the Shot 2 sampling period could have come from contamination already on the ground around the collectors either by the action of winds, shock wave,or by contamination which was displaced from the Shot 1 crater by the Shot 2 detonation. Undoubtedly, some contamination caused by the Shot 2 detonation fell on some Bikini land areas. However, in the few determinations mde, the total amount of fallout activity on the islands was too small to mterially affect the decay rate at- tributable to Shot l. The decay of Shot 2 samples can be represented by: A= Ay(t 4 623)" where A = Activity at any A,= Activity when 1 t (3.13) time t = 1 = Time in hours after Shot 2 623 = The time in hours between Shots 1 and 2 n = The decay exponent Shot 2 decays are presented in Table 3.4. The data from one sample plotted to both Shot 1 and 2 times are shown in Fige 3-36 The Shot 2 average decay exponent is about -1.4 between 600 ari 1200 hr and about 1.25 between 1500 and 4000 hr. These values are in fairly good agreement with Shot 1 values. Because of the paucity of Shot 2 decay data, the Shot 2 activities were corrected to sampling time by the use of the Shot 1 composite decey curve described in the preceding section. 3 03 3 Shot 3 Extrapolation of most Shot 3 acti Shot 1 activities. The activity due to U spectively, can be represented bys ieswas similar to that of 0239 and Npe29, ren Ag = Ago(0.0007~0-00431t f e-1e77t 4 0,00652077°24) (3.24)