RESULTS AND DISCUSSION OF RADIONUCLIDE ANALYSIS red 1¢e Anibcee. ggte Ere CRD ratean i ‘a,oie onan alin ai 37 Fission product separations (see UWFL-33 for techniques) ” and gamma spectrometric determinations were made on plankton samples collected during the Walton and the Marsh surveys. Plankton samples collected from the Walton in June 1956 were anslyzed chemically June 30 and August 29 of the same year. Similar samples collected from the Marsh in 1956 were analyzed poth for fission products and certain radioactive non-~fission product isotopes during the last week of December 1956 and the of first week of January 1957. ‘In addition to the chemical analyses, gamma spectrum curves were made on two Walton plankton samples, one of whiohk was collected just north of Bikini Atoll (station 9D), and the other in the open sea (8C) about 65 miles northwest of Bikini Atoll. In general, the observed percentages of total beta activi- ty contributed by the various fission products, corresponded ap- proximately to those expected on the basis of the Hunter and Ballou curves + Of the Walton sampies, chemicsl analyses were made on plankton from nine stations: 1E, 3A, 4D, 7D, 8A, 9A, 9C, 9D and ose dt DSeckebteticRE Tae Lecknateae in ts 1UB (Table 5). Variation in isotope percentages is great be- tween samples and no definite pattern of variation is evident between the different collecting areas. If the averages of all Banples are compared with the expected percentages (based on an average 50-day interval following detonation), the results are “3 follows: