Improvement of the technology for the long-term storage of RBMK-1000 spent fuel

Proposed changes in handling spent nuclear fuel, which are noteworthy in that they mainly dispense with regenerating it and instead use long-term intermediate storage, require a review of storage design concepts. The safety of the handling in the case of intermediate storage is increased by using the optimum water-chemical regime and a conserving mixture of calcium oxide and carbonate. An investigation of the corrosion of the structural materials of RBMK-1000 spent fuel showed that when a mixture of CaO and CaCO^sub 3^ is present, local forms of corrosion of the fuel-element jackets and containers are eliminated, and an additional barrier is formed for keeping the containers hermetically sealed, which stops the leakage of the soluble part of the fuel from unsealed fuel elements into the container water. Radionuclides are withdrawn from the solution by sorption on the precipitated calcium carbonates and oxyhydrates. Safe storage is thereby achieved in a compacted system at 3-6 t/m^sup 2^ for fifty years or more.[PUBLICATION ABSTRACT]