A mobile gamma-ray LaBr₃(Ce) detector unit for in-situ radionuclide analysis at TENORM contamination sites

Gamma-ray spectrometry, primarily utilising NaI(Tl) detectors, is widely used to measure naturally occurring radionuclides in terrestrial environments, but the use of LaBr₃(Ce) detectors is gaining prominence. Traditionally limited to vehicle-based deployments, access to hostile sites with elevated radiation has been restricted. This study demonstrates the effectiveness of a mobile radiation detection unit (MRDU) equipped with a LaBr₃(Ce) detector in such environments. The uranium Minimum Detectable Activity was 236 (16) Bq/kg at 1764.5 keV. The MRDU was deployed at the Welverdiend Agricultural Holdings, where elevated uranium levels are expected due to historic gold mining activities in the area., and the uranium activity was measured at 6477 Bq/kg. The uranium disequilibrium was investigated by comparing gamma radiation results with the total uranium concentration obtained through chemical analysis. The comparison confirmed the presence of uranium disequilibrium.