After passing through a security gate, the van descends into a tunnel that burrows under the forests of Olkiluoto, an island off Finland’s west coast. The wheels crunch on crushed stone as a gray, wet October day gives way to darkness.
“Welcome to Onkalo,” deadpans Antti Mustonen, a geologist here. Onkalo—“cavity” or “pit” in Finnish—will be the world’s first permanent disposal site for high-level nuclear waste, and a triumph for Finland.
Safety lights guide the van down through switchback turns that lead to a cavernous chamber, its walls reinforced with spray-on concrete. In just a few years, spent reactor fuel rods, encased in giant copper casks as tall as giraffes, will arrive here via elevator before robotic vehicles take them to one of the dozens of dead-end disposal tunnels that will form an ant’s nest in the bedrock.
In a freshly excavated disposal tunnel, Mustonen explains over the roar of ventilator fans that the peculiar smell comes from rock dust mixed with a trace of explosives. It is muddy underfoot—not what you want to see in a place that shouldn’t have leaks, but Mustonen says the water is only from the excavation effort.
For the rest of this article: https://www.science.org/content/article/finland-built-tomb-store-nuclear-waste-can-it-survive-100000-years