The safety of radioactive wastes in the repository depends on its capacity to confine radioactivity from being released to the biosphere. The most likely process that can lead to the release of radionuclides from a repository is the transport by groundwater. The release rate of radionuclides from the solidified blocks is controlled by the solubility limits and leaching rate of radionuclide. The present work investigates the solubility and leaching processes and their effect on the safety assessment of a radioactive waste in the repository. The paper studies both processes with different concentrations of elements. The experimental study focused on the elements; Strontium (Sr), Cobalt (Co) and Iron (Fe). To simulate the effect of radiation emitted from the radionuclides of these elements, the cement blocks that confine the elements are irradiated by Gamma (ɣ) Rays of doses; 40, 120, and 240 kGy. The results of non-irradiated and irradiated blocks are compared. The results indicate that ɣ radiation has significant effect on the pH of the leachate. The relation between leaching rate and solubility is illustrated.