A deep geological repository is a way of storing hazardous or radioactive waste within a stable geologic environment, typically 200–1,000 m below the surface of the earth.[1] It entails a combination of waste form, waste package, engineered seals and geology that is suited to provide a high level of long-term isolation and containment without future maintenance. This is intended to prevent radioactive dangers.[citation needed] A number of mercury, cyanide and arsenic waste repositories are operating worldwide including Canada (Giant Mine) and Germany (potash mines in Herfa-Neurode and Zielitz).[2] Radioactive waste storage sites are under construction with the Onkalo in Finland being the most advanced.[3]
Onkalo
was invoked but never defined (see the help page).