本文件规定了用萃取和液体闪烁计数法测定非盐水中铀同位素总活度浓度的测量方法。 该方法涵盖了活度浓度在约2·10之间的水中可溶性铀同位素的测量？当使用典型的alpha LSC仪器以60 000 s的计数时间分析1 l测试样品体积时，为3 Bq/kg和10 Bq/kg。 还可以确定比率234U/238U。该方法尚未用于其他铀同位素的测量。

This document specifies the measurement method for the determination of total activity concentration of uranium isotopes in non-saline waters by extraction and liquid scintillation counting. This method covers the measurement of soluble uranium isotopes in water in activity concentrations between approximately 2·10^？3 Bq/kg and 10 Bq/kg when analysing a 1 l test sample volume with a 60 000 s counting time with a typical alpha LSC instrument. The ratio ²³⁴U/²³⁸U can also be determined. This method has not been tested for the measurement of other uranium isotopes.