Gamma dose rate and 226Ra activity concentrations in the soil around a Mexican radioactive waste-storage center

The environmental gamma dose rate has been determined at the Mexican Storage Centre for Radioactive Waste (SCRW) and surrounding communities. The gamma dose rates were evaluated using thermoluminescent dosimeters and a portable gamma-ray spectrometer. The activity concentrations of 235U, 226Ra, 232Th, 40K, and 137Cs in soil samples were determined by gamma spectrometry. The gamma dose rates and the annual effective doses were higher at the SCRW and at border line, as compared with the surrounding communities. A site specific lineal model to describe the relationship between the outdoor gamma dose rate and the 226Ra activity concentrations in the soil is proposed.