Finland is on the verge of switching on what could become one of the most consequential infrastructure projects in the history of nuclear energy, a permanent underground repository designed to store highly radioactive waste for tens of thousands of years. Built deep beneath the island of Olkiluoto, the facility represents a long-awaited answer to a problem that has shadowed nuclear power since its earliest days, what to do with spent fuel once it is no longer usable. As countries return to nuclear energy to meet climate goals and rising electricity demand, Finland’s solution could offer a working model for safely isolating radioactive waste from people and the environment over geological timescales.
