Radiation shielding materials

Purpose: To increase the specific gravity than usual materials made of heavy concretes thereby improve the shielding performance. Constitution: Radiation shielding materials are formed with concretes using depleted uranium as aggregates. Depleted uranium aggregates are made, for example, by a method of sealing metal uranium or uranium dioxide into a vessel made of aluminum or iron, or by admixing powdery uranium oxide with additives such as bentonite and further mixing with an aqueous solution of polyvinyl alcohol, methylcellulose, etc. into a cleam state, followed by drying and solidification, etc. Since the specific gravity of depleted uranium is 18.85 g/cm3 in the case of metal uranium and 10.97 g/cm3 in the case of uranium dioxide, the specific gravity of the radioactive shielding materials can be increased to about 6 - 15 g/cm3. (Yoshino, Y.)