Strontium-90 and cesium-137 in service water; from Dec. 1979 to Jun. 1980

The samples of service water, 100 l each, were collected at the intakes of water treatmentplants and at taps after water was left flowing out for 5 min. The carriers of Sr and Cs were added immediately after the sampling, and the samples were vigorously stirred and filtered. They were 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 service water obtained from December, 1979, to June, 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 0.55 pCi/l of Sr-90 in tap water found in Wakkanai in December, 1979, and 0.05 pCi/l of Cs-137 in source water found in Katsushika, Tokyo, in December, 1979. (Kako, I.)