Sweden: Copper disposal packages
Sweden, which does not intend to reprocess its spent fuel, has developed a disposal process. Carbon steel assembly containers are inserted into over-pack containers with a copper outer shell. The overpacks designed for waste disposal in granite, which is the only suitable geological formation available in Sweden, will be placed in cells that are backfilled with bentonite, a clay that becomes totally impermeable when saturated with water, preventing any water that naturally circulates through the granite from reaching the waste packages.