Why do we need deep geological repositories?

If, 2000 years ago, the Romans had built a surface storage facility for radioactive waste instead of the Colosseum, would it still be standing today? Would the waste stored in the facility always have been safely contained?

Storage facilities are a good solution - as long as they can be monitored and maintained appropriately by humans. But we cannot rely on future generations to take over this responsibility. For radioactive waste, safe isolation is required not just for 2000 years but for tens of thousands of years.

Human society and the environment undergo constant change. Deep in the Earth, on the other hand, time practically stands still. The Earth's history shows that rock formations can remain stable over inconceivably long times and are capable of confining materials for millions of years. Deep geological disposal makes use of these features: radioactive waste is disposed of in a tight rock formation at a depth of several hundred metres where it remains isolated without any human intervention and presents no hazard to our descendants.

A drillcore from the Opalinus Clay in Northern Switzerland. The rock contains well preserved remains of marine creatures from the time when it was formed - some 180 million years ago. Findings such as these show that Nature is capable of isolating materials for extremely long time periods. (Image: Comet)