The safe geological disposal of high-level radioactive waste requires a passive multi-barrier system. This paper describes the engineered barriers foreseen in the provisional Swiss repository concept, covering both design aspects as well as evidence for their long-term performance. Disposal canisters made of carbon steel will be used for the encapsulation of spent nuclear fuel and vitrified high-level waste. The canisters are designed to corrode slowly and predictably in the repository as well a