Discover Onkalo, the mysterious place forbidden to man for 100,000 years.

It is such a unique and mysterious place that it triggers a host of contrasting emotions. Located 450 meters underground, Onkalo is made up of tunnels carved into living rock. On the way to this site, the picturesque northern landscape of tall pines can lead to existential questions. What will this place be like in 1,000 years? Or in 10,000 years? Will future generations know the danger that lies beneath their feet?

Because in a few years, Finland, where Onkalo is located, will begin to bury its used nuclear waste in this underground site. The site’s tunnels are designed to store highly radioactive waste for a period almost incomprehensible to the human mind. Once this waste is stored, no human should enter it for 100,000 years.

To date, spent fuel rods from nuclear power plants are temporarily stored in various facilities around the world. However, Finland is the first country to implement what it hopes will be a permanent solution. In two or three years, this highly radioactive waste will be buried deep in the bedrock of Onkalo, after being placed in cast iron and copper cylinders and wrapped in bentonite clay. ‘Onkalo, located 437 meters below the surface, is a winding course through a 4.5 km long tunnel. Inside, everything seems surprisingly normal. The workers work as if they were in an open-air factory, despite the fact that they are deep underground.

The way nuclear waste will be handled is also fascinating. The waste will arrive in the service area by an elevator directly from the surface encapsulation plant. They will then be transported deeper to a deposition tunnel by robotic vehicles which will deposit them in vertical holes – their final resting place.

To prepare site visitors for this unique experience, Posiva, the company that manages Onkalo, first presents a safety video. With pragmatism, this video recalls the potential dangers of the site and the security measures to adopt. Despite the serenity this video seeks to convey, the feeling of standing at the entrance to a place no human should enter for 100,000 years is overwhelming.

Onkalo’s fundamental lesson is clear: as humanity continues to advance in technology, it must also take responsibility for the long-term consequences. Onkalo is an attempt to do just that, keeping radioactive hazards away from human reach for tens of thousands of years. Only time will tell if this solution is really the right one.