A human made structure capable of lasting 100,000 years, designed to store nuclear waste. The Onkalo nuclear waste repository.
This is the subject of the documentary film Into Eternity, directed by Danish director Michael Madsen. We just watched this last night and it was an amazing film. It explores the psychological, political and philosophical issues behind the very long-term storage of nuclear waste.
One of the lasting images was the ‘landscape of thorns’; one of the potential methods of depicting to future generations what is stored there. One of the major concerns was if at some distant (or not so distant) point in the future, human society had broken down to a level where the knowledge of the facility had been lost, but also our modern communication methods and languages had also changed. What if humans tried to uncover the facility and could not understand the markers left behind by our generation?
The main conclusion was that we cannot predict what the distant future will hold and what the fate of Onkalo will be. The scientists and engineers interviewed basically said they had to deal with the theories and information that exist as at this time and the necessity to deal with the nuclear waste legacy of the previous generations (as well as our own) was too big a responsibility to just ignore. They had to take action and after considering all the issues, this was their conclusion.
There will have to be many more Onkalo facilities in other countries, but the issue of reprocessing waste still needs to be very carefully considered, if we are to reduce the waste stock and try and get as much use out of the limited resources. Thorium also needs to be considered as an alternative to plutonium, given it only stays radioactive for roughly 100 years!