Distribution of Radionuclides in Uraniferous Two-Mica Granites and Their Environmental Impact At El Sela Shear Zone, Southern Eastern Desert, Egypt

The present study discusses the natural radioactivity in the uraniferous two-mica granites and their associated environmental impacts at El Sela area. Exposure rate (ER), dose rate (DR), radium equivalent activity (Ra_eq), external hazard index (H_ex), internal hazard index (H_in ) and radio activity level index (Iγ) were calculated. These rocks are dissected by micro granite and dolerite dikes which affected by different alteration process such as ferrugination, kaolinitization, illitization and flouritization which responsible about presence of some secondary uranium minerals. The radiometric investigations revealed that the uranium average contents up to 102.6 in micro granite dike, and reach to 194 in dolerite dike respectively . All the studied rocks had low values of eTh and K content. The exposure and dose rates exceeded the public permissible values in these dikes but they were within the safety range for workers and the public in the fresh two-mica granite. The expected environmental impacts may be low due to the limited occurrence of U-mineralization and corresponding areas for radiation exposure. Some precautions and recommendations were suggested to avoid any possible environmental impacts from areas and/or raw materials of high intensity of natural radiation sources