Measurement of enhanced radium isotopes in oil production wastes in Turkey.

Gamma dose rates of oil production equipment and wastes were measured externally by survey meter. They were found to be between 0.2 µSv h(-1) and 25.7 µSv h(-1). Activity concentrations of radium isotopes in crude oil, scale, sludge, contaminated soil and water samples were determined by gamma spectrometric method. Activity concentrations of (224)Ra, (226)Ra and (228)Ra in samples varied from MDA to 132,000 Bq kg(-1). Radium isotopes enriched up to 14,667 times in scale samples. The highest value of (226)Ra was found to be 35,122 ± 1,983 Bq kg(-1) for sludge samples. Activity concentrations of a considerable number of samples were found to be higher than the exemption level recommended by IAEA. Measurement results revealed that oil production wastes caused soil contamination up to 70,483 Bq kg(-1). They may pose a radiological risk for workers and members of the public.

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

A 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 product samples were found to have activity concentrations below the minimum detectable activity (MDA) values. The maximum (224)Ra, (226)Ra, (228)Ra and (40)K activity concentrations in crude oil and refinery product samples were measured as 11.7 ± 4.5, 14.9 ± 3.5, 11.6 ± 4.5, 248.5 ± 18.5 Bq kg(-1), respectively. The maximum (224)Ra, (226)Ra, (228)Ra and (40)K activity concentrations in scale, sludge and water samples were measured as 343.7 ± 11.8, 809.2 ± 29.0, 302.5 ± 21.6, 623.0 ± 80.9 Bq kg(-1), respectively. Radium equivalent activities of the residue samples were calculated up to 1241.8 ± 42.4 Bq kg(-1). The maximum activity concentration index and the alpha index were found to be 4.2 and 4.0, respectively. The annual effective doses of residue samples were calculated below the permitted dose rate for the public, i.e. 1 mSv y(-1).