Finland Prepares Deep Geological Repository for Spent Nuclear Fuel with Long-Term Safety Considerations

Mon, 13 Apr 2026 18:52:00 +0200

Finland is set to open the world's first permanent facility for disposing of spent nuclear fuel, called Onkalo, located on the island of Olkiluoto. Construction began in 2004, and the project, costing approximately $1.2 billion, is expected to become operational soon. The facility is designed to store 6,500 tons of spent fuel in copper canisters placed deep underground in tunnels, surrounded by bentonite clay to ensure safety. Authorities emphasize the site's isolation and the stable bedrock to minimize risks. Experts note that while this method is considered the safest current option, uncertainties remain, particularly regarding long-term corrosion of the copper canisters, which could take hundreds of thousands of years to fully decay to safe levels. International reports indicate that nearly 400,000 tons of spent nuclear fuel exist globally, mostly in temporary storage. Concerns remain about proliferation risks, as separated plutonium from reprocessing could potentially be used in nu