Research on nuclear waste isolation at Stripa: an overview

A principal attribute of deep geologic disposal of radioactive waste is the high degree of physical protection it provides against human intrusion and natural events. However, even in a geologically suitable area, transport to the biosphere may occur through groundwater. There are, therefore, a number of attributes that any site should have: low permeability, low interconnected porosity, low hydraulic gradient, and high sorptive capacity. Heat generated by the waste introduces the additional requirements of chemical and mechanical stability. To assess the ability of a rock mass to isolate waste, new experimental techniques and analytical procedures must be developed to improve understanding of rock mass behavior and transport in slowly moving groundwaters. Over the past several years, thermomechanical, hydrological, and geochemical investigations have been conducted by Lawrence Berkeley Laboratory in a fractured quartz monzonite rock at a depth of some 340 m in a worked-out iron ore mine at Stripa in Sweden. This work is part of a Swedish-American cooperative program