A simple screening method for the determination of Th-230 in soil and sediment samples by gamma-spectrometry

A simple and easy to perform method for the determination of Th-230 in soil and sediment samples using gamma-spectrometry is proposed and compared wit h the more usual procedure using alpha-particle spectrometry. The proposed method involves an efficiency calibration for the specific determination of this radionuclide instead of a complete calibration of the spectra A singl e density parameter is introduced to correct the efficiencies obtained from the reference sources. The activities of Th-230 determined by gamma-spectr ometry and alpha-particle spectrometry are compared. The minimum detectable activity values obtained are completely adequate for Th-230 determination in soil and sediment samples, in which Th-230 activities are usually fairly high. Thus, this procedure is intended as a very easy way to obtain the ac tivity of this radionuclide in these types of samples, at least as a screen ing method before carrying out other more laborious procedures.