Rapid analysis of 226Ra in waters by γ-ray spectrometry

Techniques for the determination of 226Ra in waters by γ-ray spectrometry are examined, with an emphasis on methods capable of completion within 1–3 days of sample collection. Methods discussed utilise either: (i) the 186 keV 226Ra gamma ray, with the contribution from 235U being subtracted after a separate uranium determination, or (ii) measurement of ingrowing 222Rn progeny. An analysis of the statistical and systematic errors associated with each technique is presented. Examples are given of their application to analysis of uranium mine process waters.