Check your subscription status, update your details and more. The nuclear waste repository in Finland designed to outlast modern civilisation The first engineered structure built to last for 100,000 years is about to begin operations. The hope is that Onkalo, deep below ground in Finland, will offer a safe place for the country to store nuclear waste An emergency lift at the Onkalo repository in Finland, where nuclear waste will be stored indefinitely There’s a timeless quality to the tunnels at Onkalo.
Carved into the rock more than 400 metres below ground, these passageways are part of a facility built for the long term. In fact, facilities such as Onkalo “should exist intact for at least 100,000, if not a million years”, says Allison Macfarlane at the University of British Columbia in Canada, who previously served as chair of the Nuclear Regulatory Commission in the US. We are going to have to get much better at answering it, given nuclear power is expanding again, driven partly by the hunt for low-carbon energy.
There’s broad consensus that burying the waste is the best option. Radioactive elements can remain dangerous on timescales that make normal engineering look absurdly short-term. Egypt’s Great Pyramid of Giza is around 4500 years old.
Some nuclear repositories will have to contain their contents for more than 20 times longer. Before the waste becomes harmless, civilisations may rise and fall, and ice sheets may come and go. An earlier attempt to store waste on geological timescales failed spectacularly after just a few decades.
The engineers at Onkalo, and at a handful of similar sites now being planned or built around the world, think they can do much better. So, as Onkalo prepares to accept its first waste shipments in the coming months, how exactly have the engineers future-proofed their facility? Receive a weekly dose of discovery in your inbox.
We'll also keep you up to date with _New Scientist_ events and special offers. #### Physics ### Exclusive report: Inside Chernobyl, 40 years after nuclear disaster Features #### Environment ### Could geoengineering ‘ice arches’ help preserve Arctic sea ice? News #### Technology ### The electrification of everything: Best ideas of the century Features #### Technology ### How did the biggest crypto heist in history just happen? News Vibrating mattress helps clear Alzheimer’s protein from the brain### The scientific truth about collagen supplements### We are finally pinning down what makes dyslexic brains different### The best new science-fiction novels of November 2026### The best new popular-science books of November 2026### Boiling frog syndrome is often called a myth – but is it?### Inca children were drugged before being sacrificed### Hannah Fry: I lost my dad to Alzheimer’s.
Extract — continue reading at the source.