Bismuth-207 Analyses The solvent extraction techniques of Sill and Willis (1965) were used for separating and purifying 207 53. Bismuth-212 was used as a yield determinant. -Plutonium-238, 239 Analyses Plutonium-238,239 was separated by a combination of solvent extraction and anion exchange techniques 1960; Kressin and Waterbury, 1962), with electrodeposition as the final step in the separation. determine yield. (McCowan and Larsen, Plutonium-236* was used to A quantitative separation of plutonium from the coraline soils and sediments is exceptionally difficult and it is therefore essential that 236 Pu be used as a yleld determi- mant and that counting be done by alpha spectrometry. Tritium Analyses Well water samples were measured for tritium content by a liquid scintillation technigue with a minimum level of detection of 200 tritium units. ‘ nt of Energy RESULTS AND DISCUSSION Oerian Office \ ARCHIVES. / The predominant radionuclides in the terrestrial organisms are 137 Cs and 0 . , , ; Sr, whereas the marine organisms contain mainly * Provided by the USAEC Health and Safety Laboratory, New York. 50024449