Radiological assessment due to existing of natural occurring radioactive materials
(NORM) in South Rumaila oil field was achieved in this study. Different samples
including soil, sludge, scale, oil, and water were collected from different stages of
oil and gas production in Markazia Degassing Station (SDS) in South Rumaila oil
field. Radioactivity of Ra-226, Th-232 and K-40 were measured using gamma
spectrometry system based on HPGe detector with efficiency of 30%. The results
show that some locations within SDS are contaminated with NORM. The activity of
Ra-226, Th-232 and K-40 range between 18.4 to 312.8, 9.4 to 140.8 and 66.4 to
800.8 (Bq/kg) respectively. The places to be more contaminated among the other
places within the processing stages of oil and gas production within SDS are
dehydrator and desaltor stages.
In this paper, estimation of system reliability of the multi-components in stress-strength model R(s,k) is considered, when the stress and strength are independent random variables and follows the Exponentiated Weibull Distribution (EWD) with known first shape parameter θ and, the second shape parameter α is unknown using different estimation methods. Comparisons among the proposed estimators through Monte Carlo simulation technique were made depend on mean squared error (MSE) criteria