centration in the solid phase was found by dissolving the solid in mitric acid (to mke a sample with uniform activity for counting) and proceeding as abovee The activity corrections discussed in Section 322 were applied and the results, expressed in d/min/gm or d/min/ml, were corrected to 15 min after shot time by methods similar to those discussed in Section 3.3.1. The Shot 1 fallout as collected was not sufficient to enable a study to be made of the activity concentration as a function of time after the shot. However, enough sample was obtained from a few collectors to determine the activity concentrations over the entire tire cycle. The results, presented in Table 3.7, indicate that the con- centration of activity per unit weight of the solid material was of the sam order of magnitude for all samples and indspendent of time and distance within the area sampled. A slightly smaller concentration is indicated for particles collected during the first two hours than for those collected during the l2<hr period after the shote The concentration of activity in the liquid is much less than that of the solid. It should be pointed out that not much data are available and categorical conclusions should not be made. Liquid fallout samples were collected in the 30-min collector at How after Shot 4. The liquid exhibited considerable activity. The beta concentration as a function of time rag determined 4 days after Shot 4 at the Project 2.6b laboratory at Elmer. The resulte are shown in Table 3.8 Absorption and backscattering corrections were not determined, hence the activity concentration is expressed in c/min/ml. The table indicates that the beta concentration increased gradually up to 9 hr after Shot 4 and then dropped of sharply. Activity concentrations in the remaining samples of collected liquid fallout were too low to be significant. The volume of liquid collected for all samples is listed in Appendix D. Activity concen~ trations of a Shot 1 size=-graded solid sample are shown in Table 3.15. TABLE 3.7 ~ Activity Concentrations of Shot 1 Fallout Sample How Nan ime of . Raft 250.12 Raft 250.12 Collection Activity Oto Dir] ttt “| 7.10? 0 to 12 hr 0 to 12 hr 0 to 12 hr Solid Solid Liquid 8.2x107 9.30107 Concentration a/ain/em d/min/gm d/min/gmn 0679x107 d/min/ml