July 15, 2008 – Software that simulates the transport of radioactive elements beneath the Earth's surface has received a 2008 R&D 100 Award. R&D Magazine selected Southwest Research Institute's® (SwRI®) TDRW (Time Domain Random Walk) software as one of the 100 most significant technological achievements of the past year.
"As more nations develop geological repositories for high-level nuclear waste, the study and prediction of radionuclide transport in the Earth's subsurface is a key process in assessing the safety of these potential repositories," said Dr. Scott Painter, a staff scientist in the Geosciences and Engineering Division's Center for Nuclear Waste Regulatory Analyses at SwRI and principal developer of the software program.
TDRW uses a novel particle tracking algorithm in which individual particles represent packets of radionuclide mass. These particles are moved along one-dimensional pathways according to rules that closely mimic the underlying physical and chemical transport processes. That process makes it possible to represent geological complexity in much greater detail than was previously available, resulting in a better understanding of potential risks associated with radionuclide transport.
"The semi-analytical nature of the algorithm is one reason for the improved robustness and computational efficiency," Painter said, adding that the software also samples randomly from a set of many possible pathways before launching a particle, making it possible to efficiently obtain statistical estimates of total release to the accessible environment. Previous software calculated each pathway and then aggregated the results, which is vastly more expensive to compute.
TDRW already has been licensed to the U.S. Nuclear Regulatory Commission, as well as six organizations in Europe that are evaluating potential geological repositories for nuclear waste disposal.
SwRI has won 33 R&D 100 Awards since 1971. This year's awards will be presented Oct. 16, 2008, in Chicago.