ABSTRACT
This chapter deals with the general performance and waste-isolating potential of low-level (LLW) and intermediate-level (ILW) radioactive waste repositories beyond the first decades of a total operational time of 300–500 years, considering transformation processes in engineered barriers and their environment, and external impact, like possible climatic variations, and damage. The issue of long-term function of a repository has to do with the overall stability of its components, which is primarily determined by their interaction mutually and with the surrounding medium, which is the underground of on-ground repositories, and the host rock of underground repositories. The ideal function of the repositories is to maintain the waste in air-dried form until it is no longer dangerous, which is the purpose of the top liner of clay and overlying erosion-resistant cover. The roots of vegetation penetrate into erosion-resistant soil covers and remnant of roots creates channels of rainwater migrating into deeper parts of such covers and possibly in the underlying clay liners.
