Overview
- Onkalo in western Finland is awaiting a license expected within months that would make it the first permanent underground site for commercial spent fuel.
- Workers will seal used fuel rods in copper canisters and place them more than 400 meters underground in stable bedrock, with bentonite clay packed around each canister to block water and trap contamination.
- Operator Posiva says the site can hold 6,500 tons of fuel and will run into the 2120s before crews close the tunnels and seal the repository.
- Safety specialists warn the copper shells will eventually corrode, and they say the exact pace over thousands of years is uncertain even with multiple engineered and rock barriers.
- No other permanent repository is operating worldwide, Sweden is building one and France is planning one, and Finland’s environment minister left open taking small foreign waste shipments if regulators permit it.