干旱区生态环境知识资源中心

Naturally occurring radionuclides (NORs) from the Th-232- and U-238-series, which are omnipresent in the earth’s crust, can be concentrated by technical activities, particularly those involving natural resources. Although, a great deal of work has been done in the field of radiation protection and remedial action on uranium and other mines, recent concern has been devoted to the hazard arising from naturally occurring radioactive materials (NORM) in oil and gas facilities. NORM wastes associated with oil and gas operations from scale deposits, separated sludge and water at different oil fields in the eastern acid western deserts were investigated. Concentrations of the uranium, thorium, and potassium (K-40) series have been determined from high-resolution gamma-ray spectrometry. Total uranium content of samples was determined using laser fluorimetry. The levels of radioactivity were mainly due to enhanced levels of dissolved radium ions. Only minute quantities of uranium and thorium were present. The disequilibrium factor for U-238/Ra-226 has been determined. (C) 2001 Elsevier Science Ltd. All rights reserved.