Finland Nears Opening of World's First Permanent Nuclear Waste Repository as Operating Licence Is Granted

Finland has taken a major step towards opening the world's first permanent underground repository for nuclear waste. The government has granted an operating licence for the Onkalo facility in western Finland, waste management company Posiva said.

Posiva said the government handed over the licence on Thursday. With that decision, the facility built for the permanent underground storage of spent nuclear fuel has passed an important stage of legal approval.

The company made clear, however, that receiving the licence does not yet allow the facility to open. Before final disposal begins, the commissioning stage must be finalised and the necessary tests and inspections carried out.

Posiva Chief Executive Officer Ilkka Poikolainen said in a statement that this is a great and historic day for both Posiva and Finland. His remark itself shows how significant the project is considered to be for the country.

Poikolainen added that before final disposal begins, Posiva will finalise the commissioning stage, carrying out the necessary tests and inspections, which STUK, the Finnish Radiation and Nuclear Safety Authority, also needs to verify and approve.

Although 22 years have passed since construction began, no exact date has yet been decided for when the facility will start operations. Posiva said it is expected to start operations soon, but the date is not final.

Onkalo, which means cave in Finnish, will have space for 6,500 tonnes of uranium. Spent fuel from Finland's five nuclear reactors will be stored there permanently.

The storage method has also been laid out in detail. The fuel will be enclosed in copper canisters that are highly resistant to corrosion. The canisters will then be lowered into holes drilled into the bedrock, the holes will be filled with bentonite clay, and they will finally be sealed with a steel-reinforced concrete plug.

The waste will remain highly radioactive for tens of thousands of years. After about 100,000 years, according to Posiva, the levels will be about the same as the uranium ore from which the fuel was made.

Countries have been wrestling with what to do with dangerous nuclear by-products since the first plants were built in the 1950s. Currently, most of it is held in temporary storage, without a permanent solution.

Final repositories are being built in other countries, including neighbouring Sweden and France. But Finland is the first to licence its underground storage facility, and it is expected to be the first to open one.

The cost of the Onkalo site has been estimated at $1.16bn. Once the commissioning tests and STUK verification are complete, the facility will reach the final stage before starting operations — and that is what those involved are now watching for.