Cement is an important material in radioactive waste management. It is used as a solidifying agent for the concentrated wastes resulting from the treatment process. The solidification process results in immobilized wastes. To protect the human and the environment for long periods of time, the solidified waste forms should withstand the operation and storage conditions. Hence, the cement blocks should have proper mechanical and chemical properties. Moreover, the effect of radiation on the blocks should be studied to assure the retention of radionuclides by the cement matrix under radiation fields. To carry out the study, cement blocks were irradiated by Gamma radiation at doses 40, 120 and 240 KGy. The morphology of the blocks was studied before and after irradiation using X-ray Diffraction Patterns (XRD), and Scanning Electron Microscopy (SEM). The results of morphology studies are presented. The morphology studies indicated an improvement in the fixation of radionuclides on the cement matrix after irradiation.