Assessment of occupational radiation exposure of NORM scales residues from oil and gas production

Radiological hazards from external exposure of naturally occurring radioactive materials (NORM) scales residues, generated during the extraction process of oil and gas production in southern Algeria, are evaluated. The activity concentrations of 226Ra, 232Th, and 40K were measured using high-purity gamma-ray spectrometry (GeHP). Mean activity concentration of 226Ra, 232Th and 40K, found in scale samples are 4082 +/- 41,1060 +/- 38 and 568 +/- 36 Bq kg-1, respectively. Radiological hazard parameters, such as radium equivalent (Raeq), external and internal hazard indices (Hex, Hin), and gamma index (Ig) are also evalu-ated. All hazard parameter values were greater than the permissible and recommended limits and the average annual effective dose value exceeded the dose constraint (0.3 mSv y-1). However, for occa-sionally exposed workers, the dose rate of 0.65 +/- 0.02 mSv y-1 is lower than recommended limit of 1 mSv y-1for public.(c) 2023 Korean Nuclear Society, Published by Elsevier Korea LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).