Radiological hazards of TENORM contaminated soil at Oil and Gas Fields

Abstract

The presence of large quantities of TENORM contaminated soil produced during the extraction and processing of oil at oil extraction sites higher than the radiological reference levels assigned by the international organizations (UNSCEAR 2000) may cause the exposure of workers at this sites to unusual radiation hazards. This is a great importance for assessing the dose to the workers at these sites, which plays a vital rule in exploring the radiation health risks due to radiation exposure. This study aims to assess the TENORM activity concentration of the contaminated soil in some oil and gas production fields at Egypt. The assessment of the radiological hazards for the workers by estimating the annual doses and the radiation hazard indices are also studied. The obtained data showed that the activity concentration of 238U, 232Th and 40K found to be ranged from166 to 42567 Bq/Kg, 88 to 8358 Bq/Kg and 52.22 to 440Bq/Kg respectively. The calculated absorbed dose rate ranged from 132.39 – 24732.67 nGy/h, the calculated Annual Effective Dose Equivalent ranged from0.16 – 30.33 mSv/y (depending on the activity concentration of NORM contamination). The radiation hazard indices is calculated and found to be much higher than the international values. From the obtained results, it has concluded that the remediation/decontamination of the contaminated soils at the production sites that have high activity concentration is highly recommended. In addition, Egyptian regulations must be coherent to force companies to decontaminate the NORM contamination in order to reduce as much as possible the radiation worker exposure.