Strontium-90 and cesium-137 in freshwater; from Nov. 1979 to May 1980

The samples of fresh water, 100 l each were collected. The carriers of Sr and Cs were added immediately after the sampling, and the samples were vigorously stirred and filtered, then passed through cation exchange columns. Sr and Cs were eluted with hydrochloric acid from the cation exchange columns. Sr-90 and Cs-137 were separated from the sample solutions by the methods described, and their activities were counted with low background beta counters for 60 min. The net rate of sample counting was corrected for the counter efficiency, recovery, self-absorption and decay. As the environmental data, the results of Sr-90 and Cs-137 in fresh water obtained from November, 1979, to May, 1980, and the locations of sampling are given. In a table, the months and the locations of sampling, pH, and the amounts of Sr-90 and Cs-137 (pCi/l) are shown. The maximum values are 0.27 pCi/l of Sr-90 and 0.05 pCi/l of Cs-137 found in Kasumigaura in May, 1980. (Kako, I.)