Long-Term Stewardship
at the Nevada Test Site - (NTS)

John B. Walker and Paul J. Liebendorfer
Nevada Division of Enviornmental Protection

-- Summer 1998 --

     This paper was prepared for the State Tribal Government Working Group (STGWG) subcommittee on Stewardship. STGWG provides advise and input on matters related to the U.S. Department of Energy's (DOE) national Environmental Management Program for the nuclear weapons complex. The paper discusses DOE's long-term stewardship responsibilities at the Nevada Test Site.


    The Nevada Test Site (NTS) is a U.S. Department of Energy (DOE) installation occupying approximately 1,350 square miles (882,332 acres) in southeastern Nye County, Nevada. NTS is larger than the State of Rhode Island. Site features includes deserts, playas, and mountainous terrain (see Figure 1). NTS was established in 1951 as the nation's proving ground for testing and development of nuclear weapons. Between 1951 and 1992, the federal government conducted just over 900 nuclear tests at the site; 100 of these tests were conducted above ground.

    The site is situated about 65 miles (105 km) northwest of Las Vegas, Nevada. Las Vegas is home to 1.2 million residents and is one of the fastest growing metropolitan areas in the country. With visitor counts now exceeding 30 million annually, Las Vegas is also one of the world's most active resort destinations.

    The NTS occupies public lands that are administratively held by the Department of Interior, Bureau of Land Management (BLM). This means the lands are "owned" by the public, not the federal government. Nonetheless, the lands are under temporary use restrictions because they were "loaned" by BLM to the Atomic Energy Commission (now DOE) vis-a- vis four separate Public Land Orders.

    In addition to these Public Land Orders, the United State Air Force, through a DOE/Air Force Memorandum of Understanding (MOU), loaned the area known as Pahute Mesa to DOE. The MOU grants DOE unconditional use and operational control(1) of Pahute Mesa. The mesa is contiguous to the northern border of the NTS. The lands encompassing Pahute Mesa and NTS total 1,350 square miles and are "access controlled" by DOE and withdrawn from settlement, sale, location, or entry under the mining and mineral leasing laws. Although these lands are, in fact, public lands, under the current federal management structure and with few exceptions, they are restricted from all forms of public uses.

    Yucca Mountain, which is the only site being evaluated as a potential geological repository for high-level radioactive waste and spent nuclear fuel, is located on the southwestern corner of the NTS in a location known as "Area 25" or Jackass Flats. Yucca Mountain actually occupies lands under the jurisdiction of DOE, the United States Air Force, and the BLM. That portion of Yucca Mountain that occupies public lands is controlled by DOE under a temporary right-of-way permit issued by the BLM. Under the Nuclear Waste Policy Act as amended, Yucca Mountain is managed by DOE‘s Office of Civilian Radioactive Waste Management.

Contamination at NTS

    Contaminated soils and groundwater at NTS resulted from years of nuclear testing and from various research and development projects and radioactive waste disposal programs. The types of activities that led to the existing contamination could be categorized as follows:

  • Atmospheric Nuclear Testing
  • Underground Nuclear Testing
  • Safety Tests and Cratering Events
  • Nuclear Rocket Development and other R&D Programs
  • Disposal of Radioactive Waste (in shallow land fills, subsidence craters, and in greater confinement disposal shafts)

Atmospheric Testing: Prior to the 1963 Limited Test Ban Treaty, a total of one hundred atmospheric nuclear tests were conducted at NTS. The tests were detonated at ground level, from towers, balloons, and by airdrops. According to DOE, the greatest disturbance typically occurred when an air- dropped weapon penetrated the ground surface to a shallow depth before detonation. Such a test -- with an estimated yield of 100 kilotons and up -- would result in a crater about 120 feet deep and 720 feet in diameter. Because NTS was used for both atmospheric and underground nuclear testing, DOE has stated that it is not possible to fully define the level of residual contamination that remains from the atmospheric testing program.(2) Nevertheless, the number of curies generated from above ground testing was estimated at about 6 billion. Obviously, most of the fission products and other short-lived nuclides released from above ground testing were dispersed into the atmosphere and have since decayed away. DOE does acknowledge, however, that longer-lived radionuclides remain in the soil and physical structures at the site. The primary radioactive isotopes that remain from above ground testing include americium, plutonium, cobalt, cesium, strontium, and europium.

Underground Testing: Beginning in June 1957 and ending in September 1992, DOE (and its predecessor agencies) conducted over 800 underground nuclear tests at the NTS. The tests had yields ranging from zero to 1,000 kilotons. Underground testing left an estimated source term of 300 million curies in the environmental media (soil and groundwater). Because an estimated 38 percent of the tests were conducted under or within 75 meters (246 ft) of the water table, the groundwater beneath the site now contains an estimated 120 million curies of radioactivity.(3)

    There were four basic types of underground tests: shallow, borehole, deep vertical, and tunnel tests. Collectively, these tests caused significant disruption to the geologic media. They resulted in hundreds of subsidence craters and caused contamination of the subsurface geologic media, surface soils, and groundwater over an estimated 300 square mile area. In terms of absolute volume, Nevada officials contend that the NTS contains more contaminated media than any other site in the DOE weapons complex.(4)

Nuclear Safety Tests and Cratering Events: DOE conducted numerous "safety" experiments at the NTS and, while these experiments did not produced nuclear explosions, they did create significant surface contamination. These tests were conducted to determine the behavior of nuclear weapons in conventional explosive accident scenarios during handling, storage, and transport operations. Safety tests were also conducted to determine the size and distribution of plutonium particles that might result from fires and conventional explosive accidents involving nuclear weapons. Some of experiments were also performed to determine the biological uptake of plutonium by various species of animals and plants.

    The "safety" experiments were conducted at five locations on the Nellis Air Force Range and at two locations on the NTS (See Figure 4-1). According to DOE, the depth of contamination at these soil sites may vary, but probably are one foot or less at any given site.(5) DOE has estimated that these safety experiments contaminated about 2,885 acres with plutonium at levels in excess of 40 pico curies per gram.

    In addition to safety experiments, DOE conducted nine cratering events as part of the "Plowshare" program. These events used nuclear devices to excavate large volumes of earth. The materials from these nuclear detonations were literally expelled to the surface. In terms of cumulative effects, the contamination from above ground testing along with the safety shots and cratering events left an estimated 27,000 acres (42 square miles) of surface soils contaminated at levels in excess of 40 pico curies per gram. The primary isotopes of concern are plutonium, uranium, and americium with lesser amounts of cesium, strontium, and europium.(6)

Nuclear Rocket Development: In the mid-1950s, the federal government initiated a nuclear rocket testing program at the NTS. Test cells, roads, and assembly facilities were constructed at NTS Area 25, now the site of the Yucca Mountain site characterization project. Surface soils at these facilities were contaminated with radionuclides released during engine tests, and the buildings were contaminated during assembly and disassembly of the rocket motors. Some of the contaminated equipment and other materials were disposed of in nearby landfills including unknown amounts of processed reactor fuel. Leach fields in the area were also used for disposal of liquid wastes.

Radioactive Waste Disposal: NTS currently functions as a major low-level waste disposal facility for both onsite and off-sited generated defense low- level waste. Two active waste management sites are located on NTS: the Area 5 and Area 3 sites. The Area 5 site occupies 723 acres (over 1 square mile) and is located in Frenchman Flat about 12 miles north of Mercury, Nevada. Mercury is the base camp for the NTS. The Area 3 site occupies 125 acres and is located 23 miles north of Mercury in Yucca Flat. Yucca Flat was used extensively for both atmospheric and underground nuclear testing.

    Established in 1961, the Area 5 disposal site is a traditional "engineered" shallow land fill disposal facility. It is used for disposal of onsite and offsite-generated low-level waste and onsite-generated low-level mixed waste, as well as for storage of transuranic waste (TRU waste). Since the late 1980s, NTS ceased accepting TRU waste and mixed waste for storage. (Although some TRU and mixed waste was disposed of at the site, the State never officially accepted the waste for disposal.) There are 612 cubic meters of TRU waste held in temporary storage at the site, of which 53.4m3 is classified TRU. The TRU waste is destined for disposal at DOE's Waste Isolation Pilot Plant in New Mexico.

    The waste disposal facilities at Area 5 consists of 17 landfill cells, a storage building for the TRU waste, and 13 Greater Confinement Disposal (GCD) boreholes. The landfill cells (pits and trenches) contain over 500,000 curies of radioactivity. The GCD boreholes contain low-level waste, some transuranic waste, transuranic mixed waste, and classified low-level waste. The boreholes are 120 feet deep and hold about 300m3 of waste containing 9.3 million curies of radioactivity. In all, the Area 5 site probably contains about 20 million cubic feet of low-level waste.

    The Area 3 disposal site is used for bulk and packaged low-level waste. The site is comprised of four subsidence craters with areas between the craters excavated to make two oval-shaped landfill units. Conventional landfill methods are used to dispose of waste in the craters. As of 1991, approximately half of the radioactive waste disposed in the Area 3 and 5 disposal sites was defined as atmospheric testing debris generated from cleanup of surface contamination on NTS. While disposal of low-level waste generated from soil cleanup activities on NTS and the Nellis Range is an ongoing activity, during recent years about 90 percent of waste disposed of at NTS is shipped to the site by off-site waste generators. On average, each year NTS receives about 750,000 ft3 of low-level waste from 17 approved waste generators.

Industrial Sites: In addition to contamination caused by the detonation of nuclear devices and waste disposal operations, a significant amount of contamination in the form of muck piles, ponds, sumps, injection wells, inactive tanks, leach fields, waste site, etc. are present on the NTS. These sites remain as by-products of nuclear testing, various research and development programs, and related support activities. These chemical and radioactive contaminated areas, which number in excess of 2,000, are referred to as industrial sites.

Decision Process - Remediation of Contaminated Sites

    The regulatory process established for DOE's Environmental Management (EM) program at the NTS is detailed in the State/DOE Federal Facility Agreement and Consent Order (FFACO). In that agreement, DOE asserts it authority for conducting EM program activities under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), the Atomic Energy Act, and Executive Order 12580, "Superfund Implementation."

    In addition, both DOE and the State acknowledge that the FFACO is subject to other authorities including the Solid Waste Disposal Act, which includes both the Resource Conservation and Recovery Act and the Hazardous and Solid Waste Act; the Nevada Revised Statutes, including the Nevada Water Pollution Control Law, the Nevada Hazardous Waste Law, the Nevada Administrative Code, the Nevada Administrative Procedure Act; and all other applicable provisions of state and federal law. Furthermore, as part of the FFACO, the State of Nevada has stipulated that it retains all of its hazardous waste and clean water authorities and legal rights delegated by the U.S. Environmental Protection Agency and under its own laws and regulations as well. As for DOE, the FFACO stipulates that the agency does not waive any claim of jurisdiction over matters that may be reserved to it by law, including the Atomic Energy Act.

Site Investigation, Characterization and Closure Process

    Achieving site closure(s) of contaminated sites on the NTS(7) is accomplished through a regulatory scheme defined under the above referenced Federal Facilities Agreement and Consent Order (FFACO). This agreement contains a detailed process or "Corrective Action Strategy" for planning, implementing, and completing environmental corrective actions. The process is designed to produce decision(s) for closure of contaminated sites (see Figure 1-2). In general, site closure activities at the NTS are being pursued to address the following sub-project areas:

Off-Site Corrective Action Units: For the Off-Site Corrective Action Units, DOE has committed to characterize and remediate surface soils at levels that would be acceptable for multiple use activities. The underground shot cavities would be restricted, however, and DOE and/or the Bureau of Land Management would retain in perpetuity institutional control of the subsurface contamination. It should be mentioned that surface contamination at these two off-site underground nuclear test areas is limited to non-radioactive constituents such as heavy metals, fuel oils, etc. Hence, closure in place of certain limited non-radioactive contaminated areas is being considered under the FFACO.

Soils Media Corrective Action Units: The closure process for contaminated surface soils is somewhat circuitous and will likely vary for sites on and off the NTS. For example, DOE has committed to characterize and remediate radioactive contaminated surface soil plumes that straddle or lie outside the NTS boundaries such as sites on the Tonopah Test Range (TTR) and Nellis Air Force Range. These sites would be remediated and then made available for alternative "controlled" uses. Cleanup levels would generally respond to future military missions and DOE related research and development activities.

    Ongoing negotiations between the State, the Department of Defense, and DOE indicate these soil contamination areas would be remediated to a dose receptor limit of 25 millirems. According to the NTS EIS [p.4-96], these areas total about 1,670 acres. State officials recognize that "clean closure" of these sites would be cost prohibitive and generally impractical given both current and expected land uses.

    The U.S. Air Force is proposing an indefinite public land withdrawal for the TTR and the Nellis Range, and while only a small fraction of the 3.1 million acres that encompasses these ranges is contaminated, restricted public access to both ranges is maintained. Under federal law (P.L. 99-606), the Air Force must obtain congressional approval for the renewal of the Nellis Range by the year 2001.

    For the majority of contaminated soils located within the NTS boundary, DOE is planning only a characterization and long-term monitoring program. The contaminated soils in Yucca Flat, for example, will not be remediated because Yucca Flat has been set aside to support the readiness program for nuclear testing. Maintaining a defense readiness posture for nuclear testing is still the primary mission at the NTS. Accordingly, institutional control for most of the contaminated soils on NTS proper is assumed by DOE to be "in perpetuity" at the existing boundaries. Thus, it appears that "clean closure" of most of the contaminated soils on NTS would be cost prohibitive and generally impractical given both current and expected land uses. It should be noted, however, State officials may require some form of containment of surface contamination even though DOE is planning to retain restricted access to the NTS for the foreseeable future.

Underground Test Areas (UGTA) Corrective Action Units: For the underground test areas, DOE has stated that the subsurface contamination around the nuclear test cavities will not be remediated since cost-effective groundwater technologies have not been developed to remove or stabilize radioactive contaminants.(8) Nevertheless, given the uncertainties about the size and potential movement of groundwater contamination (principally tritium), DOE has committed to a subsurface monitoring program of UGTA sites for a period of at least 100 years. In addition, to restrict access to contaminated groundwater, DOE is planning to institute an in perpetuity institutional control of the contaminated sub-surface. Regardless of these planned activities, State regulatory officials will be evaluating the need for active containment of contaminated groundwater once the hydro-geologic conditions at the site are understood.

Industrial Sites Corrective Action Units: The remediation/closure process for contaminated industrial sites is based on a prioritization scheme that is largely dependent on a site's future use potential. In NTS Area 25, for example, the land is being developed in part to support certain non-defense "commercial" reuse activities. In other parts of NTS, like Yucca Flat, industrial sites would be remediate to support the readiness program for nuclear testing. In general, industrial sites that show a potential for health risks as a result of direct exposure, inhalation, and/or resuspension of contaminants will be remediated to support negotiated facility/land-use scenarios. While in some cases sites may be clean-closed, given expected restricted access and limited land-uses, most of the industrial sites on NTS will likely be remediated to negotiated levels that are acceptable for reducing risks to human health and the environment.

Postclosure and Land-Use

    It is clear that less stringent cleanup standards will result in a greater need for long-term stewardship. Since complete cleanup of the NTS is not considered cost effective or practical in the near term, the federal government will be required to maintain a long-term surveillance and maintenance program at the site for the foreseeable future. Hence, State officials contend that a long-term stewardship program for the NTS is inescapable.

    To address the question of "how clean is clean for what use", DOE is developing a comprehensive Resource Management Plan (RMP) for the NTS. Development of the RMP was undertaken as part of the recently completed NTS Site-Wide Environmental Impact Statement (EIS). DOE also made a legal commitment in the NTS-EIS Record of Decision to complete the RMP. In part, the RMP will address site closure of contaminated sites, at least in terms of major land-use categories. The plan will likely address the designation of alternative land-use areas such as "land-use zones" set aside for nuclear testing, radioactive waste management, alternative non-defense uses, and open space.

    The RMP process at NTS is, in part, being developed to comply with DOE's policy for strengthening stewardship. The policy is known as the Land and Facility Use Policy (see DOE P 430.1, dated 7/96). This policy emphasizes principles of ecosystem management and sustainable development and is functionally implemented through DOE's Order on Life Cycle Asset Management (see DOE Order 430.1, dated 8/95). While this Order requires DOE to develop a "comprehensive land-use planning process with stakeholder involvement", its primary focus is on life cycle asset management as opposed to stewardship. The order addresses a host of facility specific issues such as use of energy and utilities, infrastructure requirements, physical asset acquisition, and asset maintenance and disposition. The order is silent, however, on the relationship between comprehensive planning at the facility level and DOE's long-term stewardship responsibilities for chemical and radioactive contaminated sites.

    In reference to the NTS, it is unclear what role, if any, the RMP process will play in terms of site-specific decisions for cleanup and closure of contaminated areas. It is also unclear what role the RMP will play for long- term stewardship responsibilities such as controlling access to the site, monitoring surface and groundwater contamination, and implementing methods for preserving knowledge about the location and content of contaminated areas.

Institutional Controls

    The granting of the Public Land Orders that established the NTS(9) occurred prior to enactment of the Federal Land Management Policy Act (FLMPA). FLMPA is the BLM's authorizing legislation that sets the mission of "multiple use" for the management of public lands. Under FLMPA, the BLM is required to review the status of all pre-FLMPA public land orders to assess their continuing need and/or purpose of use. Accordingly, in 1983 BLM conducted a FLMPA "land withdrawal review" of the NTS. In the review, BLM proposed the concept of an in perpetuity withdrawal for the site with a follow-up review set at 100 years. State officials believe this proposal was actually proposed by DOE defense programs. At the time of the review, nuclear testing was an ongoing activity at the NTS (on average DOE was detonating one device per month).

    The State of Nevada conducted a formal evaluation of the withdrawal review and suggested that an in perpetuity withdrawal of public lands was inappropriate. In any event and for reasons that remain unclear, the NTS withdrawal review was never completed, and to this day, no formal administrative action has been taken to complete the FLMPA review process. In essence, the DOE and BLM are "out of compliance" with the requirements of FLMPA. This situation was further complicated by a lawsuit filed against DOE in June 1994 by Nevada's Attorney General. The lawsuit was filed to force DOE to complete a Site-Wide Environmental Impact Statement for the NTS, as well as assess the Department's low-level waste (LLW) disposal operations at the site.

    The lawsuit asserted that DOE did not have the authority to operate a LLW disposal program at the NTS, given the use restrictions contained in the Public Land Orders for the site. State officials acquiesced, however, concerning on-site disposal of waste where such wastes were directly traceable to atomic testing. Atomic testing is the stated land-use described in the Public Land Orders that established the NTS. In general, the State argued that DOE had exceeded its authority concerning the importation of LLW waste from out-of-state "off-site waste generators". The State further argued that waste disposal was never considered as a "land-use" activity under the Public Land Orders. In addition, DOE had never assessed, disclosed, or developed alternatives for the NTS disposal operation, as required per the National Environmental Policy Act (NEPA). In other words, the required environmental analysis per federal NEPA regulations was never even considered to support the federal decision that established the NTS LLW disposal program.

    After the State's lawsuit was filed, DOE initiated the development of a Site-Wide EIS that lead to the eventual settlement of the suit. Among other issues, the settlement agreement requires DOE to initiate a consultation process with the BLM to resolve the FLMPA land withdrawal review. At this writing, State officials have not been privy to DOE/BLM consultation discussions about the withdrawal review. Moreover, in the Paths to Closure site specific document for the NTS published in 1998, DOE is proposing an "in perpetuity (forever) ownership" of the site; however, the document is silent on the withdrawal review issue. As some point in the future, DOE will be required to address the legal and/or administrative issues surrounding the ownership and thus the institutional control of NTS. It remains an open question on whether or not specific federal legislation will be needed to resolve the withdrawal issue.


    From the State of Nevada's perspective, DOE's proposal to acquire in perpetuity control of certain selected areas at NTS is probably appropriate, given the amount of soil and groundwater contamination at the site. However, State officials contend that DOE must control the potential migration of contaminants to un-impacted groundwater resources. State officials have made it clear that acquiring water rights for the purpose of allowing the spread of groundwater contamination would not be an acceptable containment strategy because State law in Nevada allows the acquisition of water rights only for a beneficial use. State officials will continue to evaluate the need to impose natural resource damage assessments as a means to safeguard groundwater resources in the region.

    In terms of DOE's stewardship responsibilities, it is unclear what role existing administrative and/or legal processes, such as the NTS-RMP, the withdrawal review process, and the Paths to Closure "planning process" will have on the future of NTS. Clearly, controlling access to the site, monitoring surface and groundwater contamination, and implementing methods for preserving knowledge about the location and contents of contaminated areas will be need for the foreseeable future.


1. See Memorandum of Understanding between the Department of the Air Force Tactical Air Command Tactical Fighter Weapons Center and the Department of Energy, Nevada Operations Office, July 1982 (E-AI08-82NV10283).

2. See Final Environmental Impact Statement for the Nevada Test Site and Off-Site Locations in the State of Nevada, page 4-96.

3. ibid, page 4-85.

4. The DOE Weapons Complex is generally described as consisting of 15 major nuclear materials development and manufacturing facilities located in 10 different states. The complex produced nuclear weapons through a series of integrated manufacturing activities that included mining, milling and refining uranium, isotope separation of uranium, fuel and target fabrication for production reactors, reactor operations, chemical separation of plutonium, component fabrication, weapons assembly, and weapons testing.

5. See Federal Facility Agreement and Consent Order [FFACO] Appendix VI, page 4.1.

6. ibid, page 4-106

7. The FFACO encompasses not only NTS proper, but also parts of the Tonopah Test Range and Nellis Air Force Range, the Project Shoal Area, and the Central Nevada Test Area located in northern and central Nevada.

8. See U.S. Department of Energy, Accelerating Cleanup, Paths to Closure, Nevada Operations Office, June 1998, page 1-7)

9. The four (4) Public Land Orders for the NTS were executed in 1952, 1958, 1961, and 1965.

References Materials

Departments of the Air Force, Navy, and Interior. September 23,1991. Special Nevada Report. The report was prepared in accordance with Public Law 99-606 (DE-AC08- 88NV10715).

U.S. Department of Energy, Nevada Test Site Resource Management Plan, Working Draft 5/21/98.

U. S. Department of Energy, Moving From Cleanup To Stewardship, Office of Strategic Planning and Analysis, September 17, 1997 (Draft).

U.S. Department of Energy, Final Environmental Impact Statement, Nevada Test Site, September 1977.

U.S. Department of Energy, Nevada Field Office, (ERWM) Site Specific Plan 1994-98

-- End --