Activity concentrations of 224Ra, 226Ra, 228Ra and 40K radionuclides in refinery products and the additional radiation dose originated from oil residues in Turkey

Abstract

Total of 56 crude oil, refinery product, waste water, sludge and scale samples collected from three refineries were measured by gamma-ray spectrometry. Except for nine samples, all refinery products samples were found below the minimum detectable activity (MDA) values. 224Ra, 226Ra, 228Ra and 40K activity concentrations in crude oil and refinery product samples were measured from MDA values to 11.7±4.5, 14.9±3.5, 11.6±4.5, 248.5±18.5 Bqkg-1 respectively. 224Ra, 226Ra, 228Ra and 40K activity concentrations in scale, sludge and water samples were measured from MDA values to 343.7±11.8, 809.2±29.0, 302.5±21.6, 623.0±80.9 Bqkg-1 respectively. Radium equivalent activities of residue samples were calculated up to 1241.8±42.4 Bq/kg. Maximum activity concentration index and alpha index were found 4.2 and 4.0 respectively. The annual effective doses of four residue samples were calculated equal or above permitted dose rate for public, i.e. 1mSv/y.