Finland all set for world’s first underground N-waste burial

Olkiluoto: Deep beneath the wooded island of Olkiluoto, Finland is finalising Onkalo, the world’s first permanent geological repository for spent nuclear fuel. Descending 430 metres into 1.9-billion-year-old bedrock, the $1.2 billion “cave” is designed to isolate radioactive waste from humanity for 1,00,000 years.

The site was chosen for its immense tectonic stability, far removed from the risks of earthquakes or surface interference. At a nearby plant, unmanned machinery will seal radioactive rods into copper canisters before they are lowered into the depths. These canisters are then buried and packed with water-absorbing bentonite clay to create a multi-layered geological fortress.

Geologist Tuomas Pere notes that this subsurface isolation is significantly safer than traditional surface storage. While the global community has produced roughly 4,00,000 tonnes of spent fuel since the 1950s, most of which remains in temporary facilities, Onkalo offers a definitive, 6,500-tonne solution. With an operational licence expected within months, Finland is finally moving from theory to reality, burying the toxic legacy of the atomic age in the silent, ancient depths of the earth.

—AP