On Olkiluoto Island, off Finland’s west coast, a tunnel runs 430 metres down into bedrock that has sat largely undisturbed for about 1.9 billion years. The facility is called Onkalo. When it is full,…

On Olkiluoto Island, off Finland’s west coast, a tunnel runs 430 metres down into bedrock that has sat largely undisturbed for about 1.9 billion years. The facility is called Onkalo. When it is full,…


