Gamma-ray Spectrometry and X-ray Fluorescence Analysis for Natural Radioactivity Evaluation Associated with Radiation Hazard in Construction Materials

Abstract

This paper had threefold objectives: 1) to evaluate the natural radioactivity using the gamma spectrometry technique, 2) to correct the gamma self-absorption using the transmission method, and 3) to perform mineralogical analysis using the X-ray fluorescence (XRF) analyzer in seven different types of construction materials. The transmission method was used to measure the linear attenuation coefficient µ(E) of the samples as well as their standards at different energetic points. Next, the µ(E) coefficients were used to calculate the self-absorption correction factors (C_auto), and then they were introduced in a simplified formula to correct the fraction of the attenuated gamma radiation inside the traveled medium. Moreover, the quantitative assessment of natural radioactive elements (²³⁸U, ²³²Th, and ⁴⁰K) was done in different geological matrices. The results have shown that the mean absorbed dose and the annual average dose received by these materials are 40.65 nGy.h^-1and 0.2 mSv.y^-1, respectively. According to the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), the obtained values in no way pose a risk to human health. For compositional analysis, the X-ray fluorescence (XRF) analyzer was used to determine the concentrations of the major oxides (SiO₂, CaO, CO₂, and Al₂O₃) along with other oxides in all collected samples. The compositional results show that the self-absorption correction factors varied depending on the density and chemical composition of a sample. The XRF data shows that the mineralogical compositions are within their recommended limit. Thus, from a health safety perspective, the composition of the minerals does not pose any significant risks.