Radiological problems associated with TENORM at the oil extraction and production industry

The presence of TENORM in the oil industry occurs either as scales, which accumulate in the inner part of the pipelines that carry oil or water produced during the extraction process, or as sludge which accumulates in the bottom of tanks, separators or any other kind of equipment where this material can be trapped in. The main pathways by which the radionuclides can affect the employees are internal radiocontamination and external exposure to the highly penetrating radiation. Internal contamination occurs mainly during equipment cleaning and decontamination activities. The objective of this work was to measure the external exposure and evaluate the equivalent dose which the workers at the oil industries are submitted to. Exposure rates were measured at different locations in two different PETROBRAS oil extraction and production units in the State of Sergipe - Brazil. Measurements were made around pipelines and equipment by using a portable survey meter. A maximum value of 700 μSvh-1 at a five centimeter distance from a storage drum was measured. The very high values for the equivalent doses measured at the oil extraction and processing units indicate the necessity of establishing specific rules for the correct handling of the material. It is also necessary to signalize these areas of high radioactivity and make sure that the exposure time will be kept at a minimum. (author)