Waste Isolation Pilot Plant
The Waste Isolation Pilot Plant, or WIPP, in New Mexico, US, is a deep geological repository licensed to store transuranic radioactive waste for 10,000 years. The storage rooms at the WIPP are 2,150 feet underground in a salt formation of the Delaware Basin. The waste is from the research and production of United States nuclear weapons only. The plant started operation in 1999, and the project is estimated to cost $19 billion in total. It is the world's third such facility, after Germany's Morsleben radioactive waste repository and the Schacht Asse II salt mine.
WIPP is located approximately 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.
Various mishaps at the plant in 2014 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. The 2014 incidents involved a waste explosion and airborne release of radiological material that exposed 21 plant workers to small doses of radiation that were within safety limits.
History
Geology and site selection
In 1970, the United States Atomic Energy Commission, later merged into the Department of Energy, proposed a site in Lyons, Kansas for the isolation and storage of radioactive waste. 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. In 1973, as a result of these concerns, and because of positive interest from the southern New Mexico community, the DOE relocated the site of the proposed nuclear waste repository, now called the Waste Isolation Pilot Plant, to the Delaware Basin salt beds located near Carlsbad, New Mexico.The Delaware Basin is a sedimentary basin formed largely during the Permian Period approximately 250 million years ago. It is one of three sub-basins of the Permian Basin in West Texas and Southeastern New Mexico. It contains a thick column of sedimentary rock that includes some of the most oil- and gas-rich rocks in the United States. An ancient shallow sea repeatedly filled the basin and evaporated while the basin slowly subsided, leaving behind a nearly impermeable layer of evaporites, primarily salt, in the Salado and Castile Formations, geologically similar to other basins created by evaporitic inland seas. Over time, the salt beds were covered by an additional of soil and rock. As drilling in the Salado Formation salt beds began in 1975, scientists discovered that at the edge of the basin there had been geological disturbances that had moved interbed layers into a nearly vertical position. In response, the site was moved toward the more stable center of the basin where the Salado Formation salt beds are the thickest and are perfectly horizontal.
Some observers suggested, early in the investigations, that the geological complexity of the basin was problematic, causing the hollowed-out caverns to be unstable. However, what is considered by some to be instability is considered by others to be a positive aspect of salt as a host rock. As early as 1957, 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 1975 drilling released a pressurized deposit of the liquid from below the repository level. Constructing the plant near one of these deposits could, under specific circumstances, compromise the facility’s safety. The brine could leak into the repository and either dissolve radioactivity or entrain particulate matter with radioactive waste to the surface. The contaminated brine would then need to be cleaned and properly disposed of. There is no drinking water near the site, so possible water pollution is not a concern. After deep drilling multiple times, a final site was selected. The site is located approximately east of Carlsbad.
Waste is placed in rooms underground that have been excavated within a thick salt formation where salt tectonics have been stable for more than 250 million years. Because of plasticity effects, salt will flow to any cracks that develop, a major reason why the area was chosen as a host medium for the WIPP project.
As of March 2022, the WIPP has received 40% of the authorized amount of waste set by the Land Withdrawal Act. More rooms and panels are to be added to accommodate more waste.
Addressing public concerns via the EEG
In order to address growing public unrest concerning construction of the WIPP, the New Mexico Environmental Evaluation Group was created in 1978. This group, charged with overseeing the WIPP, verified statements, facts, and studies conducted and released by the DOE regarding the facility. The stewardship this group provided effectively lowered public fear and let the facility progress with little public opposition in comparison to similar facilities around the nation such as Yucca Mountain in Nevada.The EEG, in addition to acting as a check for the government agencies overseeing the project, acted as a valuable advisor. In a 1981 drilling, pressurized brine was again discovered. The site was set to be abandoned when the EEG stepped in and suggested a series of tests on the brine and the surrounding area. These tests were conducted and the results showed that the brine deposit was relatively small and was isolated from other deposits. Drilling in the area was deemed safe due to these results. This saved the project valuable money and time by preventing a drastic relocation.
Early construction and testing complications
In 1979, the U.S. Congress authorized construction of the facility. In addition to formal authorization, Congress redefined the level of waste to be stored in the WIPP from high temperature to transuranic, or low level, waste. Transuranic waste often consists of materials which have come in contact with radioactive substances such as plutonium and uranium. This often includes gloves, tools, rags, and assorted machinery often used in the production of nuclear fuel and weapons. Although much less potent than nuclear reactor byproducts, this waste still remains radioactive for approximately 24,000 years. This change in classification led to a decrease in safety parameters for the proposed facility, allowing construction to continue at a faster pace.The first extensive testing of the facility was due to begin in 1988. The proposed testing procedures involved interring samples of low level waste in the newly constructed caverns. Various structural and environmental tests would then be performed on the facility to verify its integrity and to prove its ability to safely contain nuclear waste. Opposition from various external organizations delayed actual testing into the early 1990s. Attempts at testing were resumed in October 1991 with US Secretary of Energy James Watkins announcing that he would begin transportation of waste to the WIPP.
Despite apparent progress on the facility, construction still remained costly and complicated. Originally conceptualized in the 1970s as a warehouse for waste, the repository now had regulations similar to those of nuclear reactors. As of December 1991, the plant had been under construction for 20 years and was estimated to have cost over one billion dollars. At the time, WIPP officials reported over 28 different organizations claimed authority over operations of the facility.
Congressional approval
In November 1991, a federal judge ruled that Congress must approve WIPP before any waste, even for testing purposes, was sent to the facility. This indefinitely delayed testing until Congress gave its approval. The 102nd United States Congress passed legislation allowing use of the WIPP. The U.S. House of Representatives approved the facility on October 6, 1992 and the U.S. Senate passed a bill allowing the opening of the facility on October 8 of the same year. The bill was met with much opposition in the Senate. Senator Richard H. Bryan fought the bill based on safety issues that concerned a similar facility located in Nevada, the state for which he was serving as senator. His efforts almost prevented the bill from passing. New Mexico senators Pete V. Domenici and Jeff Bingaman effectively reassured Senator Bryan that these issues would be addressed in the 103rd Congress. The final legislation provided safety standards requested by the House of Representatives and an expedited timeline requested by the Senate.The final legislation mandated that the Environmental Protection Agency issue revised safety standards for the facility. It also required the EPA to approve testing plans for the facility within ten months. The legislation stated that the security standards mandated in the bill were only applicable to the WIPP in New Mexico and not to other facilities in the United States. This clause caused Senator Bryan to oppose the bill, as he wanted safety standards mandated by the bill to apply to the facility in Nevada as well.
Testing and final certification
In 1994, Congress ordered Sandia National Laboratories to begin an extensive evaluation of the facility against the standards set forth by the EPA. Evaluation of the facility continued for four years, resulting in a cumulative total of 25 years of evaluation. In May 1998, the EPA concluded that there was "reasonable expectation" that the facility would contain the vast majority of the waste interred there.The first nuclear waste arrived to the plant on March 26, 1999. This waste shipment was from Los Alamos National Laboratory, a major nuclear weapons research and development facility located north of Albuquerque, New Mexico. Another shipment followed on April 6 of the same year. These shipments marked the beginning of plant operations. As of December 2010, the plant had received and stored 9,207 shipments of waste. The majority of this waste was transported to the facility via railroad or truck. The final facility contains a total of 56 storage rooms located approximately underground. Each room is in length. The plant is estimated to continue accepting waste for 25 to 35 years and is estimated to cost a grand total of 19 billion dollars.