Performance and Design of Clay Barriers for High-level Radioactive Waste Repository

Abstract

Clay barriers are important for the retardation of radionuclides in a high-level radioactive waste (HLW) repository and their performance has been analyzed based on an understanding of various processes, modeling and databases. Through the geochemical studies, we have developed models and databases for important processes, e.g., clay-water interaction and radionuclide sorption. The design for clay materials in the HLW repository has been based on an understanding of the long-term behavior of clay materials. Through the design studies, we have clarified many properties and processes of clay, e.g, extrusion/erosion into the fracture and gas migration.
This paper presents an overview of the important progress in clay performance and design and of difficulties encountered.