average insoluble percentages of 93 and 14 for the YAG 39 (two aliquots) and the YFNB 13 respectively. While such properties of barge shot fallout as the slurry nature of the droplets, diameters, densities, and individual activities have been adequately measured, it is evident that more extensive experimentation is required to provide the details of composition of the solids, their contribution to the weight of the droplets, and the distribution of activity within the contents of the droplets. 3.3.3 Activity and Fraction of Device. An estimate of the total amountof activity deposited at every major and minor station during each shot is listed in Table 3.15. Values are expressed both as fissions per square foot and fraction of device per square foot for convenience. In the case of the major stations the weighted mean and standard deviation of measurements made on the four OCC’s and two AOC,’s on the standard platform are given, while the values tabulated for the minor stations represent single measurements of AOC, collections. Basic data for both cases are included in Tables B.12 and B.14. (Tray activities were found to pass through a maximum and minimum separated by about 180 degrees when plotted against angular displacement from a reference direction; ten values at 20-degree intervals between the maximum and minimum were used to compute the mean and standard deviation (Section 4.3.2). ) The number of fissions in one OCC tray from each major station and one standard cloud sam- ple was determined by radiochemical analysis for Mo” after every shot (Reference 34). Because these same trays and samples had previously been counted in the doghouse counter (Section 2.2), the ratio of doghouse counts per minute at 100 hours could then be calculated for each shot and location, as shown in Table B.13, and used to determine the numberof fissions in the remaining OCC trays (fissions per 2.60 ft?, Table B.12). Final fissions per square foot values were converted to fraction of device per square foot by meansof the fission yields contained in Table 2.1 and use of the conversion factor 1.45 x 10*8 fissions/Mt(fission). (Slight discrepancies may be found to exist in fraction of device values based on Mo”, because only interim yields were avail- able at the time of calculation. ) Aliquots from some of the same OCCtrays analyzed radiochemically for Mo*® were also Measured on the dip counter. Since the number of fissions in the aliquots could be calculated and the fallout from Shots Flathead and Navajo was relatively unfractionated, the total number of fissions in each AOC, from these shots could be computed directly from their dip-counter activities using a constant ratio of fissions per dip counts per minute at 100 hours. Table B.14I gives the results. Shot Zuni, and to a lesser extent Shot Tewa, fallout was severely fractionated, however, and it was necessary first to convert dip-counter activities to doghouse-counter activities, so that the more-extensive relationships between the latter and the fissions in the sample could be utilized. With the aliquot measurements referred to above, an average value of the ratio of dogSe activity per dip-counter activity was computed (Table B.15), and this used to convertall counts per minute at 100 hours to doghouse counts per minute at 100 hours (Table B.14II). _The most appropriate value of fissions per doghouse counts per minute at 100 hours was then Selected for each minor station, on the basis of its location and the time of fallout arrival, and total numberof fissions calculated for the collector area, 0.244 ft®. Final fission per square values were arrived at by normalizing to 1 ft?, and fraction of device per square foot was -fomputed from the total number of device fissions as before. oe Many of the results presented in this report are expressed in termsof 10‘ fissions. For :®™ample, all gamma- and beta-decay curves in Section 3.4 (Figures 3.34 to 3.38) are plotted in :hnits of counts per second per 10‘ fissions, and the final ionization rates as a function of time each shot (Figure 3.39) are given in terms of roentgens per hour per 10‘ fissions per square men Thus, the estimates in Table 3.15 are all that is required to calculate the radiation inten- tess. which would have been observed at each station under ideal conditions any time after the Sation of fallout. It should be noted, however, that the effects of sampling bias have not been ely eliminated from the tabulated values and, consequently, will be reflected in any quantity Tmined by means of them. Even though the use of weighted-mean collector values for the 55