Sarsenbayev Dauren, Tournassat Christophe, Steefel Carl I, Wainwright Haruko M
Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139.
Energy Geosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720.
Proc Natl Acad Sci U S A. 2025 Jul 8;122(27):e2511885122. doi: 10.1073/pnas.2511885122. Epub 2025 Jul 3.
The modeling and simulation of the Cement-clay Interaction-Diffusion field (CI-D) experiment at the Mont Terri site in Switzerland presented here demonstrates that it is possible to capture the multiscale physical and chemical features of natural and engineered barrier systems for radionuclides. The simulations are successfully carried out with the newly developed CrunchODiTi high-performance computing software that accounts for multiple continua, including a continuum representing the electrical double layer (EDL) developed along negatively charged clay particles in clay rock. The simulation also accounts for both the complex three-dimensional (3D) geometry, expected as the norm in a geological waste repository, and the anisotropy of the geological formation. In addition, the high resolution of the model makes it possible to include "skin effects" developed at the interface between highly reactive materials, in this case between the high pH cement and the circumneutral but electrostatic Opalinus Clay. The successful history matching with the field experiment demonstrates that the distinct geochemical and physical properties of the cement and the Opalinus Clay in the CI-D experiment can be accounted for. Such analyses are essential for developing a defensible safety case for the underground storage of radioactive waste.
本文介绍了瑞士蒙特特里地下实验室开展的水泥-黏土相互作用-扩散场（CI-D）实验的建模与模拟，结果表明能够捕捉天然及工程放射性核素屏障系统的多尺度物理和化学特征。采用新开发的CrunchODiTi高性能计算软件成功进行了模拟，该软件考虑了多个连续介质，包括一个代表沿泥岩中带负电黏土颗粒形成的电双层（EDL）的连续介质。模拟还考虑了复杂的三维（3D）几何形状（预计地质废物处置库中常见）以及地质构造的各向异性。此外，模型的高分辨率使得能够纳入在高活性材料之间的界面处形成的“趋肤效应”，在此情况下是在高pH值水泥与接近中性但带静电的奥帕林努斯黏土之间的界面处。与现场实验的成功历史拟合表明，CI-D实验中水泥和奥帕林努斯黏土的独特地球化学和物理性质可以得到解释。此类分析对于为放射性废物地下储存制定可靠的安全案例至关重要。
