139 Quantitative Estimation As the chemical analysis of the samples for alpha emitting radionuclides was being completed, it was decided to evaluate further the total alpha survey techniques for the possibility of more general application. The total alpha counting data from the lagoon samples were used again to obtain the total alpha concentrations using more conventional selfabsorption correction methods (based on geometrical considerations) and the range of the alpha particles in the sample (7,8). Using the energy of each alpha radiation emitted from radionuclides found in Bikini sediments, each alpha particle range in calcium carbonate was calculated from its range in standard air (as found in Evans (10)) using Braggs rule in the form R; Caco 3 = Ri air + (.06 - .0086 Z) log 4 M _ .01 2; 5 (2) where: ui i m Ni 9 atomic No. of Caco. = 10.0 atomic No. of Sie = 2 u MN R = range in mg/cm? alpha particle decay energy in Mev M = mass of Ave = 4 The mean alpha particle range for the mixture of radionuclides in each sample is then: Or riedlander, Kennedy and Miller. Nuclear and Radiochemistry, John Wiley and Sons, 1964. pg. 95.