ABSTRACT
Deep-underground isolation of nuclear waste presents geotechnical problems for which there is little if any practical experience upon which to draw. Heat generated by the buried waste introduces coupled thermal, mechanical, chemical and fluid flow processes related to the geological isolation. The very long isolation times involved further compound the issues. As a consequence, unprecedented reliance must be placed on predictive numerical modeling in the design of a nuclear waste repository.
Numerical analysis in geo engineering has conventionally been based on a continuum hypothesis. The presence of joints, fractures and other discontinuities in a rock mass can significantly affect these processes and the degree of coupling. Recent advances in discontinuum analysis permit a more accurate representation of rock discontinuities in a geo-numerical model for a waste repository. This paper describes several studies in which discontinuum models have been used to improve the prediction of the repository performance and develop a better understanding of the response of the geological environment.
