Environmental Health Center

“WIPP” is the abbreviation for the Waste Isolation Pilot Plant, a U.S. Department of Energy (DOE) facility in southeastern New Mexico, 26 miles southeast of Carlsbad. The facility was built to serve as the nation’s first geological repository for permanent disposal of transuranic wastes and transuranic mixed wastes, which are transuranic wastes that also have hazardous chemical components. If it receives approval to open, the WIPP would be the first such facility in the world.

Transuranic wastes generally consist of protective clothing, tools, glassware, equipment, soils, and sludge that have become contaminated with radioactive materials at nuclear weapons production facilities in the United States. Only defense-generated transuranic wastes would go to the WIPP. Under federal law, the WIPP is not authorized to accept high-level radioactive wastes or spent nuclear fuel.

Management of the WIPP Facility

In 1993, DOE created the Carlsbad Area Office (CAO) to lead its transuranic waste disposal efforts. CAO coordinates DOE’s transuranic program at waste-generating sites and national laboratories. The CAO manager reports to DOE’s assistant secretary for environmental management at DOE headquarters in Washington, D.C., and receives administrative support from DOE’s Albuquerque Operations Office. Westinghouse Electric Corporation is the WIPP program’s managing and operating contractor. Sandia National Laboratories is the program’s lead technical contractor.

A Brief Chronology of WIPP-Related Events

More than 40 years ago, in 1955, the U.S. Atomic Energy Commission (AEC) asked the National Academy of Sciences (NAS) to study permanent disposal methods for radioactive wastes from nuclear weapons production in the United States. (AEC was disbanded in 1974. Some of its functions, including those related to disposal of transuranic waste, eventually became the responsibility of DOE.) A 1957 NAS report to the AEC recommended that transuranic and high-level wastes be buried in geologic formations and that the feasibility of using salt beds or salt domes as a disposal medium be investigated.

In 1970, the AEC tentatively selected a nuclear waste repository site in salt deposits near Lyons, Kansas. In 1972, the federal government withdrew that site from consideration for the repository because of concerns that drilling in the vicinity had compromised the salt deposits’ geologic integrity.

In the mid-1970s, the U.S. Geological Survey identified a salt formation east of Carlsbad, New Mexico, as a possible site. A first borehole, drilled to 3,000 feet, found salt bed deformations and pressurized brine; these conditions suggested that waste might escape from the site. To avoid these problems, the site was moved seven miles further southwest, to its current location.

After environmental studies of the new site were completed in 1979, Congress authorized construction of the WIPP. In the legislation that authorized the WIPP, Congress expressed its intention that the facility be developed to demonstrate safe methods for disposal of transuranic waste.

DOE drilled the first exploratory shaft at the current site in 1981 and two years later decided to proceed with full construction of the WIPP. Construction and maintenance activities have continued at the site ever since.

Before the WIPP would be able to open, the 10,240 acres of land surrounding the site had to be withdrawn from public use. The site is owned by the federal government and had been under the control of the U.S. Department of the Interior’s Bureau of Land Management. In January 1991, the Department of the Interior attempted to administratively transfer control of the site to DOE. In October of the same year, the state of New Mexico filed a successful lawsuit against DOE, arguing that Congress, and not the executive branch alone, should make the transfer. In October 1992, Congress passed the WIPP Land Withdrawal Act, which assigned authority for the land to DOE and gave the U.S. Environmental Protection Agency (EPA) substantial responsibility for regulating many of DOE’s activities at the WIPP.

In September 1996, Congress passed and the President signed into law the WIPP Land Withdrawal Act Amendments. The amendments exempted the WIPP from Resource Conservation and Recovery Act (RCRA) land disposal restriction requirements. Congress, DOE and EPA agreed that this exemption was appropriate because the WIPP was already subject to comprehensive regulation under the Atomic Energy Act, the WIPP Land Withdrawal Act, and other portions of RCRA. The amendments also struck requirements in the original act that DOE conduct underground tests onsite with transuranic waste to determine whether it could be disposed of safely. In doing so, Congress ratified a conclusion DOE and other agencies had reached several years earlier–that the site’s safety performance could be adequately assessed with a combination of nonwaste tests at the site and laboratory mathematical models.

Before the WIPP can open, DOE must obtain EPA certification that the facility is in compliance with EPA disposal standards for transuranic wastes. EPA is required to make a certification decision within one year of receiving a complete compliance certification application. DOE applied for certification on October 29, 1996. After receiving the DOE application, EPA asked for additional information; on May 16, 1997, EPA declared DOE’s application complete. If EPA certifies that the WIPP meets the disposal standards and other legal requirements are satisfied, the facility can begin accepting waste 30 days after receipt of certification, or as early as May 1998.

Before the WIPP can open, DOE must also obtain a hazardous waste permit from the State of New Mexico and issue a record of decision on the Supplemental Environmental Impact Statement. Finally, Congress must fund the disposal activities it has authorized.

Site Characteristics

Figure 1.WIPP Facility and
Stratigraphic Sequence

Source: U.S. Department of Energy, Carlsbad Area Office.

Based on recommendations by NAS, DOE decided that deep underground disposal in a suitable rock formation would be the safest, most practical, and most cost-effective means of permanently disposing of transuranic wastes. For a rock formation to be suitable, it should be highly stable, contain no circulating groundwater, be in an area where severe earthquakes or volcanic eruptions are highly unlikely, and be deep enough to allow for buffers of the same rock above and below the storage area.

NAS also recommended salt deposits as one of the disposal media for radioactive waste. Salt, according to NAS, offers several advantages: most salt deposits are in stable geological areas; the presence of salt demonstrates the absence of flowing fresh water (which would have dissolved the salt beds); salt is relatively easy to mine; and salt formations will eventually “creep” and fill in mined areas and seal the radioactive waste from the environment.

The site chosen for the 2,150-foot-deep WIPP is a 16-square-mile tract of federal land in the arid rangelands of southeastern New Mexico. The site consists of a thick layer of rock salt deposited about 225 million years ago. The low rainfall in the desert environment limits the amount of water that will move through the ground in the vicinity of the WIPP. Fewer than 30 people live within 10 miles of the WIPP site.

Although the WIPP site is under the control of DOE and is in a sparsely populated area, there is oil drilling, gas drilling, and potash mining in the vicinity. Because transuranic waste remains radioactive and must be kept isolated for thousands of years, some have expressed concern that future drilling or mining could disturb the site centuries from now, when government controls over the repository may have deteriorated.

In an October 1996 report, the Committee on the Waste Isolation Pilot Plant of the National Research Council (which is administered by NAS) found that “provided it is sealed effectively and remains undisturbed by human activity, . . . the WIPP repository has the ability to isolate [transuranic] waste for more than 10,000 years.” It also found that “the only known possibilities of serious release of radionuclides appears to be from poor seals or some form of future human activity that results in intrusion into the repository.” The committee recommended that “speculative scenarios of human intrusion should not be used as the sole or primary basis on which to judge the acceptability of the WIPP.”

WIPP Construction

Figure 2. Layout of the Waste
Isolation Pilot Plant

Source: U.S. Department of Energy.

WIPP excavation began in 1981 and continued throughout the 1980s. Four vertical shafts provide access and ventilation to the underground portion of the WIPP, where transuranic wastes will be deposited if the facility opens. This underground portion, which is 2,150 feet below ground level, is to consist of 56 large rooms–each about 300 feet long, 33 feet wide, and 13 feet high. By 1988, seven of these rooms had been constructed. Construction of additional rooms will resume when the need arises. Upon completion, the WIPP as currently designed could hold more than 6 million cubic feet of transuranic wastes or about 850,000 55-gallon drums.

The above-ground portion of the WIPP facility includes the Waste-Handling Building, where containers of transuranic wastes are to be unloaded and their contents inventoried, inspected, and prepared for disposal underground; a health physics laboratory; an exhaust filter building; emergency electric generators; and staff offices. The WIPP site also has its own fire department, ambulance service, and mine rescue capability.