226Ra in groundwater could be analyzed by various methods. LSC (liquid scintillation counter) is used to measure its activity of Ba co-precipitates with Hisafe III scintillation cocktail solution. Counting efficiency was obtained using NIST
226Ra standard solution in triplicate and calculated
226Ra concentration using the efficiency values.
226Ra values of 19 groundwaters having Gross-
α concentrations of more than 5 pCi/L ranged from ND (
≤ 0.1 pCi/L) to 1.18 pCi/L. Geologic settings of the 19 areas are composed of granitic rocks of Pre-Cambrian and Jurassic and Cretaceous, gneiss (schist) of Pre-Cambrian, and volcanic rocks of Cretaceous. No relationship was shown among
226Ra a concentrations and in-situ water quality data, and Gross-
α, uranium, radon concentrations.
Keywords: 226Ra;LSC;Gross-α;Uranium;Geologic setting;