Finland's Nuclear Time Capsule Ready

Finland is on the cusp of activating a pioneering infrastructure project, a permanent underground repository for highly radioactive nuclear waste designed for geological timescales. Situated approximately 400 to 450 meters below the surface on Olkiluoto island, the Onkalo facility represents a long-sought solution to the challenge of safely managing spent nuclear fuel for tens of thousands of years.

The repository employs a robust, multi-barrier safety system. Spent fuel is encased in copper canisters, then sealed within corrosion-resistant capsules. These are surrounded by swelling bentonite clay and finally embedded in stable, 1.9-billion-year-old bedrock, ensuring multiple layers of containment against water and environmental exposure.