guidelines for selecting locations for permanent deep-geologic high-level radioactive waste repositories required containment of waste within waste packages for only 300 years. A site would be disqualified from further consideration only if groundwater travel time from the "disturbed zone" of the underground facility to the "accessible environment" (atmosphere, land surface, surface water, oceans or lithosphere extending no more than 10 kilometers from the underground facility) was expected to be less than 1,000 years along any pathway of radionuclide travel. Sites with groundwater travel time greater than 1,000 years from the original location to the human environment were considered potentially acceptable, even if the waste would be highly radioactive for 200,000 years or more.