The Waste Isolation Pilot Plant (WIPP) in southeast New Mexico is the nation’s only operating deep geologic repository for radioactive wastes.
Opened in 1999, the U.S. Department of Energy site stores canisters filled with transuranic (TRU) radioactive waste—rags, tools, clothing, soils and other debris contaminated with man-made radioactive elements—from nuclear weapons production facilities and cleanup sites. The waste is kept 2,150 feet below ground in the Salado Formation, a giant salt deposit that stretches from northern Mexico through southeastern New Mexico and into west Texas. Salt beds keep the waste dry and seal it away from groundwater that could eventually move the waste to the surface.
More than 90,000 cubic meters and 11,000 shipments of TRU waste have been transported to WIPP. Historically, the largest contributors of waste to WIPP have been the Idaho National Laboratory, the Rocky Flats site in Colorado, the Savannah River Site in South Carolina, the Hanford site in Washington and the Los Alamos National Laboratory in New Mexico.
The U.S. Environmental Protection Agency and the New Mexico Department of Environment are the two agencies primarily responsible for regulating WIPP.
In February 2014, two isolated events happened at WIPP. First, on Feb. 5, 2014, a salt-haul truck caught fire and was subsequently extinguished. This event caused the temporary evacuation and closure of the underground storage area. Several workers were treated for smoke inhalation, but no serious injuries resulted from the fire.
On Feb. 14, a monitor device detected radiation in the air at the above-ground portion of the site. Subsequently, 17 workers tested positive for exposure to radiation, although not at levels that would cause health concerns, according to the Department of Energy. The site has ceased operations while the cause of the Feb. 14 radiation leak is investigated.
Congress authorized the WIPP facility in 1979, following years of testing to determine if the underground salt deposits outside Carlsbad, N.M., would be an appropriate storage site for radioactive wastes. The DOE National Security and Military Applications of Nuclear Energy Authorization Act of 1980, enacted in December 1979, approved funding to construct the site, but allowed only defense-generated waste to be stored there.
In 1981, the State of New Mexico sued the federal government to halt construction of the site. The settlement of that lawsuit gave New Mexico the right to conduct independent testing and monitoring of the site, and established a Consent and Cooperation agreement between the state and the Department of Energy that was subsequently amended to require that the site comply with state environmental laws.
In 1992, Congress passed the WIPP Land Withdrawal Act, which permitted waste to be moved to the site. The Act also required WIPP to comply with federal Resource Conservation and Recovery Act, or RCRA, and Solid Waste Disposal Act standards and be certified by the U.S. Environmental Protection Agency. The law prohibited WIPP from accepting any used nuclear fuel or other high-level radioactive waste, even for testing purposes.
Following further testing and certifications in the 1990s, WIPP officially began accepting waste shipments in March 1999.
Types of Wastes Stored at WIPP
TRU waste is radioactive material that is heavier than uranium, has a half life greater than 20 years, and activity greater than 100 nanocuries of per gram of waste. There are two types of TRU wastes stored at WIPP: contact-handled waste, which emits relatively little radiation and can be handled by workers; and remote-handled waste, which emits greater levels of radiation and requires heavier shielding and remote-handling equipment. According to law, remote-handled TRU waste will only account for about 4 percent of all waste stored at WIPP.
By the Numbers:
- 2,150: Depth, in feet, of WIPP’s underground storage facility
- 90,000: Amount, in cubic meters, of contact-handled TRU waste stored at WIPP
- 350: Amount, in cubic meters, of remote-handled TRU waste stored at WIPP
- 11,000: Shipments to WIPP since its inception in 1999
- 22: Number of Department of Energy legacy TRU waste sites cleaned up