. . a ev, Pee a 7 we : te - . . tae Sa Set tae O, Aa . ' . : . vos oe Dee eee toat a ee Bismuth-207 Analyses The solvent extraction techniques of Sill and Willis were used for separating and purifying 207 54. (1965) 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 yield determi- nant and that counting be done by alpha spectrometry. Tritium Analyses Well water samples were measured for tritium content by a liquid scintillation technique with a minimum level of detection of 200 tritium units. ‘ nt of Energy RESULTS AND DISCUSSION eatorian’s Office \ ARCHIVES 7 The predominant radionuclides in the terrestrial organisms are 137 Cs and 90 ; . . . Sr, whereas the marine organisms contain mainly * Provided by the USAEC Health and Safety Laboratory, New York.