Summary:
- The article discusses Finland's Onkalo nuclear waste repository, the world's first deep geological repository for spent nuclear fuel.
- The repository, located 430 meters underground, is designed to safely store nuclear waste for up to 100,000 years, using a multi-barrier system to prevent radioactive materials from reaching the surface.
- The project, which has been in development for over 40 years, is seen as a pioneering effort in the safe and long-term disposal of high-level nuclear waste, setting a model for other countries to follow.