Research from The University of Texas at Austin shows that rock salt, used by Germany and the United States as a subsurface container for radioactive waste, might not be as impermeable as thought or as capable of isolating nuclear waste from groundwater in the event that a capsule or storage vessel failed.
A team of researchers from the university has used field testing and 3-D micro-CT imaging of laboratory experiments to show that rock salt can become permeable. Their findings, published in the Nov. 27 issue of Science, has implications for oil and gas operations, and, most notably, nuclear waste storage. The team includes researchers from the university’s Cockrell School of Engineering and Jackson School of Geosciences.
“What this new information tells us is that the potential for permeability is there and should be a consideration when deciding where and how to store nuclear waste,” said Maša Prodanovic, assistant professor in the Department of Petroleum and Geosystems Engineering. “If it’s an existing nuclear waste storage site, you may want to re-evaluate it with this new information.”
Salt generally blocks fluid flow at shallow depth, a feature that allows oil reservoirs to form. But scientists have long suspected that salt becomes permeable at greater depth. Jackson School professor James E. Gardner confirmed this theory through laboratory experiments with synthetic rock salt.
Cockrell School doctoral student Soheil Ghanbarzadeh tested the idea against field data from natural rock salt. During summer internships he examined oil and brine distributions in rock salt in a set…