142 topendix Table 3. Alpna Activities of the Bravo Crater "Standard" ( Nuclide Activity pCi/fag + 2S.D. 24 an 37.38 + .46 239,2405,, 70.14 + 4.7 238, 238) 234) 226p4 aa 4.96 1.96 2.45 1.06 1.06 + + + + ¢ .46 53 .61 .17 .17 21854 21456 1.06 + 1.06 + 117 17 21054 2.93 + .96 Total 124.1 + 4.9 thicknesses greater than 4.58 n/c was thus used to calculate the total alpha radioactivity in the “standard” semple. To maasure the total alpha radioactivity of the many lagocn sediments, only one sample was prepared for ezch station. To avoid needing to measure the concentrations of the members of the 233 li decay series in each sample, the imean range was computed only for the 12 lagoon sediments for which these data were available; the range in these samples were then plotted against the total alpha radioactivity in each sample to derive an average dependence of the mean range to the total alpha radioactivity present in the various samples (Appendix Figure 2). In the high activity samples the range is primarily a function of the Pu and Am radionuclides.