Non-destructive determination of low-level210Pb and226Ra with an ordinary high-purity Ge-detector

A convenient non-destructive method for the determination of low level²¹⁰Pb and²²⁶Ra with an ordinary high-purity Ge-detector is presented. The ordinary Ge-detectors used in this work were available to measure 46.5 keV -rays of²¹⁰Pb. These detectors were also useful for the non-destructive analysis of low-level²²⁶Ra in lime-stone and calcium chemicals when a stream of nitrogen gas was maintained around the detectors. By this method, measurements could be carried out not only for²¹⁰Pb and²²⁶Ra but also for other -emitting radionuclides simultaneously, using the same detector. The detection limits of about 1 Bq per sample for²¹⁰Pb and about 0.05 Bq per sample for²²⁶Ra, respectively, were estimated, when the samples were counted for 1–2 days.