Multibarrier Copper-Base Containers for High-Level Waste Disposal

Copper and aluminum bronze have been shown to exhibit a high degree of kinetic stability in anticipated repository environments, including mildly oxidizing conditions under high gamma fields. The nature of the thermodynamic and kinetic stability of the metals is discussed. It is proposed that a robust, composite waste container composed of a copper mantle surrounding an inner shell of high-strength aluminum bronze would make the best use of the corrosion- and creep-related properties of the metals. Several designs and closure techniques are suggested. A bimetallic, centrifugally cast cylinder with a diameter and wall thickness appropriate to a high-level waste burial container has been produced. The advantages of the bimetallic casting are discussed, as are the potential multifunctional applications of composite containers of this type. Suggestions for future work are proposed. Creation of an“engineered analog” is suggested as an additional redundant safeguard in the proposed repository.