Study and Simulated the Natural Radioactivity (NORM) U-238, Th-232 and K-40 of Igneous and Sedimentary Rocks of Al-Atawilah (Al-Baha) in Saudi Arabia

• 作者: Bashayer M. Al-Zahrani Haifa S. Alqannas Safia H. Hamidalddin
• 来源期刊: 核科学与技术国际期刊(英文)
• 学科: 物理学
• 关键词: Natural Radioactivity Gamma-Ray Spectroscopy Activity Concentration Igneous and Sedimentary Rocks Simulated in T Time
• 年，卷（期）: 2020,（4）
• 页码范围: 171-181
• 页数: 11页
• 分类号: O57

摘要

In this work, gamma-ray spectroscopy based on semiconductor hyper pure germanium (HPGe) detector was used to evaluate the activity concentrations of the natural radionuclides (U-238 (Ra-226), Th-232 and K-40) and the fallout nuclide (Cs-137) for thirty samples of igneous and sedimentary rocks of Al-Atawilah (Al-Baha). The mean values of the activity concentrations of U-238 (Ra-226), Th-232, K-40 and Cs-137 in the igneous samples are found as (11.0, 11.50, 1172.71, 1.47) Bq/Kg respectively. In the sedimentary rocks, the mean values of the activity concentrations of the natural radionuclides (U-238 (Ra-226), Th-232 and K-40) and the fallout nuclide (Cs-137) equal to (12.04, 13.18, 1131.36, 1.60) Bq/Kg respectively. The averages of radiological hazards (<em>Ra</em>_<em>eq</em>, <em>H</em>_<em>ex</em> and <em>I</em>_{<em><span style="white-space:nowrap;"><span style="white-space:nowrap;">&gamma;</span></span></em>}) were calculated and found to be within the UNSCEAR permissible limit values (370 Bq/kg for <em>Ra</em>_<em>eq</em>, and 1 for <em>H</em>_<em>ex</em> and <em>I</em>_{<em><span style="white-space:nowrap;"><span style="white-space:nowrap;">&gamma;</span></span></em>}), except for a slight increase of average value of <em>I</em>_{<em><span style="white-space:nowrap;"><span style="white-space:nowrap;">&gamma;</span></span></em>} in the igneous rock samples (1.36). The results indicate that the dose rate values depend on the kind of rocks (high in some igneous rock samples, and most of sedimentary rock samples have low dose rate). The activities of naturalnuclides were predicted and simulated in T time using a written MATLAB R2020a script based on the average activity concentrations and respective half-lives of U-238 and Th-232 series, and K-40, this is to evaluate the future effects of natural radionuclides on the population and estimate the human inputs in the future.