Elemental composition and natural radioactivity of refractory materials

In recent years not too much attention has been paid to radiation risk to the people and the environment caused by exposure to ionizing radiation originating from naturally occurring radioactive materials (NORM). In this context, a study was conducted to investigate the elemental composition, using X-ray fluorescence spectrometry (XRF) measurements, and radioactivity concentration, performed using high-resolution gamma-ray spectrometry, in refractory samples placed inside two medium voltage cabinet in use by oil refinery as refractory. The results obtained from XRF measurements highlighted the high presence of Zirconium. From the measured gamma-spectra, the average activity concentrations were determined for 226Ra , 232Th and 40K. The obtained results were then compared to values from other locations around the world. The corresponding dose rate was also estimated and compared both with the values of H ∗(10) obtained by “in situ” measurements. In addition, the annual effective dose equivalent for workers was also evaluated, starting from the activity concentration evaluated by gamma spectroscopy, and the obtained value of about 0.8mSv/year was referred with limits proposed by legislation.