Finland approves the world’s first permanent repository for spent nuclear fuel

Finland has approved the operation of the world’s first permanent repository for spent nuclear fuel. The underground Onkalo facility, built in the municipality of Eurajoki in the country’s southwest, is expected to begin operating soon, although the exact date has not been set.

The repository is operated by Posiva, which will conduct the necessary tests and inspections before the facility opens. The procedures must be reviewed and approved by the Finnish Radiation and Nuclear Safety Authority.

Construction of the facility, excavated in solid rock, began 22 years ago—a longer period than is generally needed to build a nuclear power plant, estimated at between seven and 15 years, depending on the country and the type of reactor. Posiva’s director described the approval as a historic moment for the company and Finland.

Onkalo has a capacity of 6,500 tonnes of uranium and will house spent fuel from Finland’s five nuclear reactors. The radioactive elements, which remain hazardous for millennia, will be placed in corrosion-resistant copper canisters, lowered into underground tunnels and sealed with reinforced concrete.