Finland becomes first country to get permission to store nuclear waste permanently deep in rock

Finland is the first country in the world to give permission to store spent nuclear fuel permanently deep underground. On 22 October 2026, the Finnish government granted a licence to the company Posiva for the Onkalo repository. It lies next to the Olkiluoto nuclear power plant in the municipality of Eurajoki, on the west coast of Finland. Posiva may handle and permanently dispose of up to 6,500 tonnes of spent fuel from the Finnish nuclear power plants Olkiluoto and Loviisa.

The licence does not mean that the first load goes underground straight away. Posiva must first finish the last tests and checks. After that, the Finnish Radiation and Nuclear Safety Authority, STUK, inspects the installation. Only when STUK agrees may the company begin. There is no date for this yet. The government's decision rests on a positive safety assessment that STUK gave on 4 August 2026.

How Onkalo shields the waste

Spent nuclear fuel stays radioactive for a very long time. Onkalo is therefore designed to keep the waste away from people and nature for at least 100,000 years. It does this with three layers of protection, one after another. Above ground, the fuel is first sealed in copper canisters. The canisters are then placed underground in holes drilled into the rock, packed in bentonite clay: a clay that swells when it gets wet and so seals the canisters. The third layer is the hard bedrock around them, at a depth of about 430 metres.

In total there will be about 3,300 canisters, with at most 60 a year. Posiva expects to keep disposing of canisters until the 2120s. After that, the tunnels will be filled and the repository closed; the Finnish state then takes over responsibility. The licence itself runs until the end of 2070. Within ten years, Posiva must hand in a new safety case to STUK.

Posiva is owned by the two Finnish companies that produce nuclear power: TVO (60 per cent) and Fortum (40 per cent). Under Finnish law, they are themselves responsible for their waste. The site at Olkiluoto was chosen in 2000, digging of the tunnels began in 2004, and at the end of 2021 Posiva applied for the licence. According to the trade publication NucNet, Sari Multala, the minister for climate and the environment, spoke warmly about the decades of work behind the repository. Posiva chief executive Ilkka Poikolainen called it a historic day for the company and for Finland.

What does this mean for the road to the singularity?

A future with far more technology needs far more clean electricity, and nuclear energy can supply it day and night. One of the biggest questions around nuclear energy has always been: where do you put the waste for good? Finland is now the first to show that a country can give a fully worked-out answer to that, approved by the regulator. That it took about 25 years from choosing the site to getting the licence shows how much care such a step needs. Other countries can build on the Finnish experience now that the first deep repository is close to being used.

What is the technological singularity? Read the explanation →