A new study, “Building Confidence in Models for Complex Barrier Systems for Radionuclides,” highlights a breakthrough in the modeling and simulation of underground nuclear waste interactions. Led by Massachusetts Institute of Technology Ph.D. student Dauren Sarsenbayev, assistant professor and ANS member Haruko Wainwright, and scientists Christophe Tournassat and Carl Steefel, the research shows how cutting-edge, high-performance computing simulations closely align with real-world experimental data from the Mont Terri underground laboratory in Switzerland. The alignment enhances confidence in the long-term safety of geological nuclear waste repositories.