The level of natural radioactivity in eight sediment rock samples from western south Sinai were collected from three different locations Um Bogma, Wadi Um Hamd and wadi Sad El-Banat, also two granite samples were collected from Gabal Gattar, north eastern desert in Egypt was investigated. The gamma-ray spectrometry system with hyper pure germanium (HPGe) detector has been used to determined radioactivity concentrations. Samples were subjected to sulphuric acid leaching processes with the same parameters of solid liquid ratio S/L, acid concentration and leaching time. After leaching process, the pregnant solution was separated from the residual and the latter was dried. The two units, named the pregnant solutions and residuals were also measured radiometrically using the hyper-pure germanium detector to determine the activity concentrations (Bq/kg) of the different radionuclides of samples.
The results showed that the relation between the sum of activities of 238U in both solutions and residuals with originals have two modes. The first mode is represented by the sum of 238U activities in leachate and residual is nearly equal the activity in the original sample. In the second mode, the sum is higher than the original.
These variations depend mainly on the grain surfaces in the different rock types and its content high concentration of Pb. This phenomenon varied in magnitude within the different radionuclides in each sample. Also the leachability of U by the chemical analysis using several acidic leaching experiments for uranium have been performed by sulfuric acid.