Projecting Risk into the Future: Failure of a Geologic Repository and the Sinking of the Titanic

Over one hundred years ago, the “unsinkable” RMS Titanic struck an iceberg in the North Atlantic and sank on its maiden voyage from Southampton, UK, to New York City.  This “accident” and others, such as the tragedy at Fukushima Daiichi, can provide insight into the challenges that face the geologic disposal of radioactive waste.   In this presentation, I reflect on the essential differences between analyzing the failure of engineered structures vs. a “failed” geologic repository.  Perhaps, the most important difference is that for most countries there will only be a single repository, and we will never “see” that repository “in operation,” as the operational phase of a geologic repository comes long after it has been filled with waste and sealed. The time-scales considered for the geologic disposal of radioactive waste place special demands on the analysis of how engineered and geologic systems might fail. As scientists and engineers, we should reflect on the sobering reality of how difficult it is to project the future behavior of a geologic repository over extended spatial and temporal scales that stretch over tens of kilometers and out to a hundreds of thousands of years. I will offer a few short observations on the state of the U.S. nuclear waste management program and ideas for moving forward.