It is shown that radioactive fission fragments can be safely buried by converting the liquid wastes into solid materials. From the point of view of providing maximum localization of the fragments in a minimum volume of materials such as glass there are undoubted advantages. An analysis is given of the physicochemical principles for preparing these materials and certain features are considered in the behavior and state of radioactive fission fragments included in them. By using methods of fractional chemical and x-ray structural analyses we have shown the heterogeneity of the structure of the fused materials and the related features of behavior of fission fragments during leaching. It has also been shown that the ionizing radiation helps to increase the crystalline fraction in the materials.