A research team at the University of Texas at Arlington has received a $567,831 grant from the Department of Energy to study the rock materials that best prevent the escape of radiation from nuclear waste disposal facilities.
The researchers led by earth and environmental sciences associate professor Qinhong Hu will examine the movement of fluids and radioactive atoms through six variations of low-permeable rock formations, according to a Sept. 5 UTA press release. Those include clay/shale, salt rock, crystalline rock, and tuff, Hu told RadWaste Monitor this week.
“This range of generic low-permeability barrier materials was selected based on their relevance and recognition in both natural and engineered barrier systems for a long-term performance of [a] geologic repository,” he said by email.
Safe encasement of dangerous radioactive materials has been key to selecting existing storage disposal sites and those still being planned. For example, the Department of Energy buries its transuranic waste within underground salt deposits at the Waste Isolation Pilot Plant in southeastern New Mexico. The long-planned nuclear waste repository at Yucca Mountain in Nevada would be built within volcanic tuff, with a backfill of bentonite clay.
The Texas researchers will aim for a “mechanistic or process-level understanding” of the movement of fluids and radionuclides, the university said. They will also “quantify the uncertainty around the materials for isolation purposes.”
The grant was awarded in January through DOE’s Nuclear Energy University Program. The three-year funding, beginning in October, will pay for stipends and tuition for two doctorate-level researchers and a number of undergraduate research assistants, along with materials and other research and travel costs, Hu said.
The project will in part involve small angle neutron scattering instruments at the National Institute of Standards and Technology in Maryland and the Oak Ridge National Laboratory in Tennessee. The systems will enable the research team to comprehensively characterize the pore structures of the low-permeable barrier materials to help ensure safe performance of disposal facilities, according to Hu.
“Our unique contribution in the project is the improved understanding and appreciation of pore structure … of low-permeable barrier materials to lead to a reduced movement of radionuclides,” he wrote.
Hu has been researching this topic for more than two decades, including working on preparations for Yucca Mountain starting in 1997 when he was a postdoctoral fellow for geologic science at the Lawrence Berkeley National Laboratory in California. He continued work on the project as a staff scientist at the Lawrence Livermore National Laboratory.
