NUCLEAR WASTERComparing Geologic Repository Assessment Tools
A computer modeling system is designed to answer critical safety assessment questions about future disposal options for spent nuclear fuel deep underground and the system of tunnels, containers and possible concrete-like barriers used to keep the radioactive material contained far from the surface and water sources.
Researchers from Sandia National Laboratories and partner national laboratories will compare their Geologic Disposal Safety Assessment software framework to the safety assessment software of international peers at a late-April workshop.
The Sandia-led Geologic Disposal Safety Assessment framework is a computer modeling system designed to answer critical safety assessment questions about future disposal options for spent nuclear fuel deep underground and the system of tunnels, containers and possible concrete-like barriers used to keep the radioactive material contained far from the surface and water sources, said Emily Stein, a Sandia manager overseeing the development of the framework. Work on this framework is supported by the Department of Energy’s Spent Fuel and Waste Science and Technology campaign.
“The goal of the framework is to provide the DOE a flexible and intuitive simulation and analysis capability for investigating different deep geologic repository systems,” Stein said. “It has to be flexible to look at different host rocks and the different processes that can occur in those different kinds of rocks. It has to work with different 3D-engineering designs. The DOE also wants it to be fairly straightforward to explain how various thermal, chemical, hydrological and mechanical processes were coupled in the model. There’s all this different stuff that goes on underground and the DOE wants to be able to think about the connections between those processes in a way that is somewhat intuitive.”
Sandia started working on the framework in 2012. Comparing the results from Sandia’s software against the results from the safety assessment software of international peers will build confidence in the software and models, Stein said. The comparison could also highlight areas for improvement.
Importance of a Flexible Software Framework
The U.S. has approximately 90,000 metric tons of spent nuclear fuel — uranium rods no longer used for producing electricity at nuclear power plants — stored at nuclear power plants across the country and this number will keep growing. While nuclear provides more than half of the carbon-free electricity in the U.S., a permanent solution to spent nuclear fuel is needed.
