SLIDE 14 Comparison of Bikini Ash to unfractionated fallout. The per cent of fallout beta activity due to fission products present on day 26 after formation was tabulated. The hypothetical beta activity was based on a fallout composition which was unaltered due to chemical or physical mechanisms which affected certain fission product nuclides. This unaltered composition was referred to as unfractionated. This unfractionated fallout was calcyhated from thermonuclear neutron fission data given by Crocker for U (Cr65). The comparison between per cents, based on the measured values of Bikini Ash beta activity and unfractionated fission product beta activity, required conversion of the Yamatera and Tsuzuki data sets (Ya56, Ts55) into percent fission product beta,actiyity. That is, we exclude the besgactivity of the activation products Ss, Ca and the GRgnsuranic nuclide U for comparison purposes. It was assumped by us that U, which represented 20% of the beta activity on day 26 in the Tsuzuki results represented 20% of the beta activity in the Yamatera data. As previously implied, the term fractionation indicated alterations of nuclide composition in fallout debris. The ratio of two nuclides in fallout was often used to describe fractionation quantitatively (§g6!). The denominator of the ratio was taken to be the activity of “Zr (Fr61). quantify fractionation between two nuclides, To the beta activity ratios were compared by Freiling (Fr61). The term “degree of fractionation” was used by him and represented the range of variability of the nuclide ratio. revi of Ja ese ults indi d to us that the activity patios for 13270. P27. Bf Payce, [BeeuRh and Teacape (ratioed to measure 957 END beta activity) did not differ by a tor greater than abgut 1.5 from the unfractionated ratios. Ratios for 186gata, th at, 885 Y, rods? and 1435, differed by about a factor of 2, and 8 Sr and I Bre, 29T 6 differed by about actor 3 re ive the rac nated fos. T nuclides Y, tobeer, Pare 185oe° 182ne° Y38r° ee teee, Cee and sae were in greater abundance relative to unfractionated debris. DAY 26 COMPOSITION OF BRAVO - Nuclide Xy ty Bs ca v3 0 Pu (a) FALLOUT % Bikini Aah Beta Activity Hypothetical Thermonuclear Neutron Fission, % Total Beta Activity 0.013 8.0 0.05 0.031 4.1 _ 20 0.0004 — — 0.20 _ Greater Than Hypothetical Less Than Hypothetical 12am NS py Mintg MB, 14 La *y, Ry, ieRh Te, nee SE eyey tT, 19 Approximately Same As Hypothetical P7r Nb, MTe, Sy, Ce, 144 Pr