The Czech Republic has a well-developed nuclear programme with two nuclear power plants currently in operation and three operational near-surface repositories serving for the disposal of institutional and operational low-and intermediate-level waste. Spent nuclear fuel will be disposed of in a deep geological repository to be constructed in crystalline or metamorphic rock approximately 500 m below the surface. Czech Ca-Mg bentonites will be used as the buffer and backfilling material. Steel-based materials are currently considered as the reference metallic materials in the Czech disposal canister concept. The preferred design is based on a doublewalled canister with an inner shell of stainless steel and an outer shell of carbon-steel. Both parts of the canister must provide mechanical stability; the wall of the carbon-steel canister will be strengthened for corrosion-resistance purposes. The presented work focuses on canister design as confirmed by means of mechanical, thermal and criticality calculations and a detailed experimental corrosion plan.