Patent Number: 039830500
Section: claims

1. In the method of storing high-level radioactive liquid wastes by calcining the waste to remove the liquid, thereby forming a high-level radioactive calcine, placing the calcine in a metal canister, sealing the metal canister and placing the sealed metal canister in a moisture-containing environment for cooling and long-term storage, the improvement comprising: adding powdered portland cement to the canister containing the calcined wastes so that the cement is in contact with the inner surface of the wall of the canister before the canister is sealed, whereby, should the canister wall fail and develop an opening to the environment, moisture from the environment will enter the canister, mix with the portland cement, forming concrete which will harden, seal the opening and prevent the escape of any radioactivity from the canister to the environment. 2. The method of claim 1 wherein the powdered cement is mixed with the calcine to form an intimate mixture before the mixture is placed into the canister. 3. The method of claim 2 wherein the mixture contains at least 1 part by weight of cement powder per 10 parts by weight of calcine. 4. The method of claim 3 wherein the canister is placed in a water-filled tank for cooling and long-term storage. 5. The method of claim 1 wherein the powdered portland cement is added to the canister to form an outer annulus in contact with the inner wall of the canister and the radioactive calcine is in the center of the canister surrounded by the cement. 6. The method of claim 5 wherein the outer annulus of cement powder is at least about 1 inch in thickness. 7. The method of claim 6 wherein the canister is placed in a water-filled tank for cooling and long-term storage.