[304884] Artigo – CBMRI – Congresso Brasileiro de Metrologia das Radiações Ionizantes

Resumo: This study aims to computationally evaluate the exposure of workers subjected to natural radiation emitted by ⁴⁰K, ²³⁸U and ²³²Th radionuclides present in crude oil during prospecting activities in oil fields, in which professionals are directly exposed. The workers were represented by female (FASH3) and male (MASH3) computational anthropomorphic phantoms coupled with the radiation transport code MCNPX2.7.0. Due to the diversity of petroleum exploration environments, this study presents conversion factor (CF) data for effective dose for three exposure conditions: soil, scale (oil encrusted on pipe walls), and sludge. Effective doses, expressed in Sv/Gy, were calculated by taking the average of the equivalent doses of FASH3 and MASH3 organs. The main results obtained, and the Monte Carlo simulation relative percentage errors (in parentheses) showed that the highest CF calculated was 1.4 (0.7) in the sludge case with ⁴⁰K scenario, and the lowest of 0.52 (0.8) with the soil and the ²³⁸U radionuclide. These results suggest that the scenario composed of scale is the most critical for workers and that ⁴⁰K is the radionuclide that contributes the most to individual exposure, especially when the sludge scenario is used.