2026 Volume 25 Pages 1-4
The determination of radioactivity in environmental samples becomes difficult when radionuclides are non-uniformly distributed within volumetric samples measured in close geometry. In this study, a simple experimental method was developed to evaluate the radioactivity of such non-uniform samples using the counting-rate ratio obtained from measurements in normal and inverted orientations. Simulated soil samples containing 137Cs were prepared in polypropylene U8 containers using alumina powder to reproduce various activity distributions. An empirical relationship between the counting-rate ratio and the detection efficiency for non-uniform volumetric samples was established experimentally. The radioactivity of non-uniform samples could be estimated with an accuracy of approximately ±20%. This simplified calibration method provides a practical and conservative approach for routine environmental radioactivity measurements.
