Accuracy associated with the activity determination by in situ gamma spectrometry of naturally occurring radionuclides in soils

Publication date: October 2016
Source:Journal of Environmental Radioactivity, Volumes 162–163
Author(s): A. Baeza, J.A. Corbacho, J. Guillén
In situ gamma spectrometry (ISGS) is a technique mainly focused on the determination of man-made radionuclides deposited on soils. It is widely used for the radioactive characterization of soils in which there has been an incorporation of such radionuclides, especially ¹³⁷Cs. Its use for the activity determination of naturally occurring radionuclides in soils has been more limited, and the accuracy associated with those measurements has yet to be treated extensively. There are numerous factors affecting the accuracy of the activity determination of naturally occurring radionuclides, such as the assumed soil geometry, the soil's geological and mineral composition, its moisture content, etc. The present work studies the accuracy associated with the ISGS determination of the activity concentrations of natural radionuclides in soils using a portable HPGe detector. For ⁴⁰K and ²³²Th activity determinations, the uncertainties associated with ISGS are generally of the order of 15%. However, ²²⁶Ra activity determined from its daughters ²¹⁴Pb and ²¹⁴Bi can be significantly overestimated when there is a major presence of ²²²Rn in the air around the detector. Finally, absorbed dose rate in air values were calculated from the naturally occurring radionuclide concentration in soils. The results showed good correspondence between the values obtained from ISGS and those obtained from laboratory determinations with the same soils.



from Radiology via xlomafota13 on Inoreader http://ift.tt/1U8oNyL
via IFTTT