Radium and potassium-40 in solid wastes from the oil industry

Activity concentrations of 226Ra, 228Ra and 40K in scales and sludge generated during oil extraction and production operations were determined using an HPGe gamma spectrometric system. Concentrations ranged from 42.7 to 2110.0 kBq kg−1 for 226Ra, 40.5 to 1550.0 kBq kg−1 for 228Ra and 20.6 to 186.6 kBq kg−1 for 40K. The magnitude of these results demonstrates the need of screening oil residues for their radionuclide content in order to decide about their final disposal.