The waste is from the research and production of United States nuclear weapons only. It is located approximately 26 miles 42 km east of Carlsbad , in eastern Eddy County , in an area known as the southeastern New Mexico nuclear corridor, which also includes the National Enrichment Facility near Eunice, New Mexico , the Waste Control Specialists low-level waste disposal facility just over the state line near Andrews, Texas, and the International Isotopes, Incorporated facility to be built near Eunice, New Mexico.
Various mishaps at the plant in brought focus to the problem of what to do with the growing backlog of waste and whether or not WIPP would be a safe repository. Ultimately the Lyons site was deemed unusable due to local and regional opposition, and in particular the discovery of unmapped oil and gas wells located in the area. These wells were believed to potentially compromise the ability of the planned facility to contain nuclear waste.
The Delaware Basin is a sedimentary basin formed largely during the Permian Period approximately million years ago. It contains a 4,β9, ft 1,β2, m thick column of sedimentary rock that includes some of the most oil- and gas-rich rocks in the United States. Over time, the salt beds were covered by an additional ft m of soil and rock. Some observers suggested, early in the investigations, that the geological complexity of the basin was problematic, causing the hollowed-out caverns to be unstable.
As early as , the National Academy of Sciences recommended salt for radioactive waste disposal because at depth it would plastically deform, a motion called "salt creep" in the salt-mining industry. This would gradually fill in and seal any openings created by the mining, and in and around the waste.
Exact placement of the construction site in the Delaware Basin changed multiple times due to safety concerns. Brine deposits located below the salt deposits in the Delaware Basin posed a potential safety problem. The brine was first discovered when a drilling released a pressurized deposit of the liquid from below the repository level. The brine could leak into the repository and either dissolve radioactivity or entrain particulate matter with radioactive waste to the surface.
