Assessment of the annual dose of the occupational workers involved in dry decontamination of NORM contaminated equipment in Egyptian oil and gas industry

Processing activities for oil and gas production have been known to produce a large amounts NORMs (Naturally Occurring Radioactive Materials) at elevated concentrations as by-product waste streams. This means that TE-NORM (technologically enhanced naturally occurring radioactive materials) can pose Radiation exposure levels that are generated by waste from the oil & gas industry. which necessitate constant monitoring and attention during NORM decontamination of oil and gas equipment. The most common source of exposure is external and internal radiation coming from the Ra & Ra (U-238 and Th-232 series) radionuclides and their progenies. In this study, we focus on the yearly dose of workers who are working in recently established dry decontamination facility as a dedicated tool for NORM contaminated tubing and other small installation’s decontamination using abrasive blasting machines instead of High-Pressure Jetting Water facilities, in purpose to minimize the waste volume produced as well as reduce the exposure time of workers involved in the decontamination process. Workers were monitored for one year on three months’ basis using the TLD badges. Two groups of workers were formed of 5 persons for each group, working back-to-back 15 days on 15 days off in field basis, for around 10 working hours/day. All recorded personal doses were within the occupationally acceptable dose limits (20mSv/Year). Most of the workers were exposed to doses range of 700 1000 μSv/ 3 months, two readings were away of this range, but even though still within the occupationally acceptable dose limits. It was found that used protective measures against external and internal contamination help enhancement of workers’ protection against NORM hazards as well as minimizing the NORM contaminated wastes using the dry decontamination technique to a very far extent in comparison to high pressure jetting water technique which had positive impact on the environment in terms of the radioactive decontamination in oil and gas working environment.