Characterization of the TE-NORM waste associated with oil and natural gas production in Abu Rudeis, Egypt

The present study was conducted to characterize the Technically Enhanced Naturally Occurring Radioactive Materials (TE-NORM) waste generated from oil and gas production. The waste was characterized by means of dry screening solid fractionation, X-ray analysis (XRF and XRD) and gamma-ray spectrometry. Sediment of the TE-NORM waste was fractionated into ten fractions with particle sizes varying from less than 100 mu m to more than 3 turn. The results showed that the TE-NORM waste contains mainly radionuclides of the U-238, U-235 and Th-232 series. The mean activity concentration S Of Ra-226 (of U-series), Ra-228 (of Th-series) and K-40 in the waste samples before fractionation (i.e. 3 mm) were found to amount to 68.9, 24 and 1.3 Bq/g (dry weight), respectively. After dry fractionation, the activity concentrations were widely distributed and enriched in certain fractions. This represented a 1.48 and 1.82-fold enrichment of Ra-226 and Ra-228, respectively, in fraction F8 (2.0-2.5 mm) over those in bulk TE-NORM waste samples. The activity ratios of U-238/Ra-226, Pb-210/Ra-226, Ra-223/Ra-226 and Ra-228/Ra-224 were calculated and evaluated. Activity of the most hazardous radionuclide Ra-226 was found to be higher than the exemption levels established by IAEA [International Atomic Energy Agency, 1994. International Basic Safety Standards for the Protection against Ionizing Radiation and for the Safety of Radiation Sources. GOV/2715/94, Vienna]. The radium equivalent activity (Ra-eq), radon (Rn-222) emanation coefficient (EC) and absorbed dose rate (D-gamma r) were estimated and these are further discussed. (c) 2004 Elsevier Ltd. All rights reserved.