Corrosion Aspects of High-level Waste Disposal in Salt Domes

In the ELSAM/ELKRAFT waste management project it is planned that the high-level waste is classified, encapsulated in canisters and finally deposited in a deep hole drilled in a salt dome. In the present report corrosion aspects of the canisters after deposition are discussed. The chemical environment will probably be a limited amount of brine coming form brine inclusions in the surrounding salt and moving up against the temperature gradient, the temperature at the canister being in the range of 100-150°C.

The possible types of corrosion and the expected corrosion rates for a number of potential canister materials (mild steel, autenitic and ferritic stainless steels, Ni-base alloys, copper, titanium and a few combinations of materials) are discussed. Mild steel (possibly combined with an inner layer of copper or titanium might possibly be appropriate choice of material for the canister.