Post on 12-Oct-2020
Yucca Mountain, Nevada - A proposed geologic repository for
high-level radioactive waste
Robert A. Levich and John S. Stuckless U.S. Department of Energy, Las Vegas, Nevada 89134
U.S. Geological Survey, Denver, CO 80225
ABSTRACT
Yucca Mountain in Nevada represents the proposed solution to what has been a lengthy
national effort to dispose of high-level radioactive waste, waste which must be isolated
from the biosphere for tens of thousands of years. This chapter reviews the background
of that national effort and includes some discussion of international work in order to
provide a more complete framework for the problem of waste disposal. Other chapters
provide the regional geologic setting, the geology of the Yucca Mountain site, the
tectonics, and climate (past, present, and future). These last two chapters are integral to
prediction of long-term waste isolation.
INTRODUCTION
Since the dawn of the Atomic Age more than 60 years ago, the operation of
nuclear powerplants, as well as the development and manufacture of nuclear weapons,
has generated large amounts of radioactive waste. Some of the radioisotopes in this
waste are in low concentrations or have short half-lives. Most of these "low-level"
wastes can be disposed of in shallow trenches. Other radioactive waste contains
radioisotopes in higher concentrations or isotopes with long half-lives, greater than 1,000
ykars. ~h?se"'high-level" wastes must be disposed of in a manner that will isolate them
from the biosphere for tens of thousands of years.
Worldwide, there has been a long-standing scientific consensus that the best
method for permanent disposal of high-level radioactive waste is in deep geologic
repositories (see for example National Academy of Sciences, National Research Council
report, 1957, and Nuclear Energy Agency report, 1995). There are many analogues that
support this conclusion, for example, ore deposits that have existed for millions of years,
organic materials that have existed in caves for hundreds of thousands of years, and
anthropogenic items that have been preserved underground for thousands to tens of
thousands of years (Winograd, 1986; Brookins, 1986a; Alexander and Van Luik, 1991 ;
Miller et nl., 1994; Stuckless, 2000, 2002)
Nuclear waste destined for disposal comes from several sources. The largest
quantity is commercial spent nuclear fuel (SNF), consisting of he1 assemblies from
civilian nuclear powerplants that contain enriched uranium fuel pellets that have been
removed after completing their useful life in the production of electricity. Approximately
20% of our Nation's electricity is produced at 74 sites in 33 States that host 11 8
con~mercial nuclear power reactors, more than 100 of which are still in operation.
Currently (2006), more than 40,000 metric tons of heavy metal (MTHM) are stored in 33
States at 72 commercial reactor sites and a single storage site (Commonwealth Edison's
consolidated storage facility at Morris, Illinois). It is estimated that if the existing nuclear
powerplants continue to operate for their license periods of 40 years, they would generate
about 87,000 MTHM of SNF. If each reactor were granted an additional 10 years by
license extension, they could produce a total of about 105,000 MTHM of SNF (c.f. Dyer
and Voegele, 200'1; U.S. Department of Energy, 2001).
Other sources of waste include:
1. U.S. Department of Energy (DOE) spent nuclear fuel - spent nuclear fuel
from reactors aboard naval vessels and irradiated fuel from weapons
production and research reactors.
2. High-level radioactive waste - radioactive by-products resulting from the
reprocessing of commercial or defense spent nuclear fuel, which fails to
separate small amounts of plutonium and other transuranic elements.
3. Surplus weapons plutonium.
4. Transuranic wastes - by-products from fuel assembly and the manufacture
of weapons.
HISTORY OF NUCLEAR WASTE MANAGEMENT
The Atomic Energy Act of 1954 assigned to the U.S. Atomic Energy Commission
(AEC) the responsibility of managing spent nuclear fuel from civilian reactors. This Act
also permitted private industry to construct and operate nuclear reactors for generating
electricity. In the following year, the National Academy of Sciences (NAS), at the
request of the AEC, began a study of waste disposal and in 1957 reported " . . . that
radioactive waste can be disposed of safely in a variety of ways and at a large number of
sites in the United States." The NAS also indicated that ". . . the most promising method
of disposal of high-level waste . . . is in salt deposits" (National Research Council, 1957).
As a consequence, the AEC comn~issioned the U.S. Geological Survey (USGS) to review
the Nation's salt deposits. On the basis of investigations between 1962 and 1969, an
abandoned salt mine near Lyons, Kansas, was selected for further study. However,
owing to the technical problems such as the discovery of old abandoned wells, as well as
intense local opposition to the development of a waste disposal site, the project was
canceled. As a consequence, the search for alternative geologic repositories was
broadened to investigate salt deposits in other States, as well as a variety of other rock
types, as discussed below.
In addition to the search for geological repositories in the United States, there was
a perceived need to investigate other geologic and nongeologic means for nuclear waste
disposal, which included widely diverse alternatives as represented by the following:
1. Sub-seabed disposal - spent nuclear fuel andlor devitrified high-level waste
sealed in specially designed canisters and buried within deep sea sediments of
an abyssal plain in a tectonically stable area far from plate boundaries.
2. Island disposal - isolation of waste in a deep geologic repository beneath an
uninhabited island that lies in a remote area and lacks natural resources.
3. Ice sheet disposal - storage of waste in containers to be placed on the surface
of ice sheets (Greenland or Antarctica), with heat from radioactive decay
causing the container to melt its way toward the bottom of the ice sheet.
4. Deep-hole disposal - placement of waste-filled canisters in drill holes as much
as 10,000 m (6 mi) deep, below circulating ground water and far below the
accessible environment.
5. Rock-melt disposal - placement of waste in liquid or slurry form in a deep
drill hole or underground rock opening, with the heat of radioactive decay
eventually melting the surrounding rock to form a molten solution of waste
and rock that would eventually solidify into a relatively insoluble mass
resistant to leaching.
6. Deep well injection - injection of waste into a deep geologic formation
capped by a layer of impermeable rock.
7. Space disposal - several alternative concepts were considered, including (1)
transport to and injection of waste into the sun, (2) emplacement of waste on
the moon, and (3) sending reprocessed waste into orbit midway between Earth
and Venus.
8. Long-term surface storage - continued storage in (1) water pools that cool
spent f ~ ~ e l rods and shield workers from radiation, or (2) dry storage casks;
these are considered to be temporary measures requiring constant monitoring
and security.
Treatment methods to mitigate the waste-disposal problem also were considered.
Reprocessing of waste is a chemical process in which spent nuclear fuel is dissolved,
fissile uranium and plutonium are recovered, and the remaining high-level waste is .
vitrified (Cowley, 1997). The process is expensive but produces a greatly reduced
volunle of waste. During President Carter's administration (1977-1980), the United
States established the policy of not reprocessing commercial spent nuclear fuel.
Partitioning and transmutation of radioactive waste as an adjunct to reprocessing also was
considered (Cowley, 1997). In this method, the actinide waste is combined with uranium
(or uranium + plutonium), fabricated into mixed oxide, and reinserted into a reactor.
After numerous cycles the waste actinides would be converted to stable isotopes or ones
with very long half-lives; however, additional waste streams are generated during each
reprocessing cycle. Furthermore, transmutation does not reduce the quantities of long-
lived fission products including 9 9 ~ c and 1 2 9 ~ , and these must be disposed of in a geologic
repository.
Inherent technical difficulties and other serious disadvantages limit consideration
of most nongeological alternatives for waste disposal, and thus the effort to find an
acceptable geologic solution was expanded. In 1972, The AEC contracted with the
USGS to evaluate several different methods of geologic disposal, principally in geologic
media other than salt. Five modes of disposal were to be considered: (1) very deep drill
holes (9,140 to 15,250 m), (2) geometric array of shallow to moderate depth drill holes
(300 to 6,100 m), (3) shallow mined chambers (300 to 3,000 m), (4) cavities with man-
made (engineered) barriers, and (5) explosion cavities (6 10 to 6,100 m). The final report
(Ekren et nl., 1974) cited 30 previous reports on geologic disposal and concluded that
hydrologic isolation was of paramount importance. One specific recommendation was
"the Basin and Range Province of the western United States, particularly the Great Basin
exclusive of seismic-risk zone 3,' appears to have potential for mined chambers above
deep water tables in tuff, shale, or argillite" (Ekren et al., 1974, p. 2). The body of the
report provides several examples of favorable geologic features at the Nevada Test Site.
During the 1970s and '80s, DOE (and predecessor agencies) investigated several
alternative sites and rock types:
1. Salt sites (other than Lyons, Kansas) -three salt domes (two in Mississippi
and one in Louisiana) and four bedded salt units (Paradox Basin in Utah and
Pern~ian Basin of West Texas) were evaluated (U.S. Department of Energy,
1984a,b; 1986a,b,c).
2. Basalt Waste Isolation Project, Hanford, Washington - investigation of
layered basalts of Miocene age in the Cold Creek Syncline of the Columbia
Plateau, on the Hanford Nuclear Reservation (U.S. Department of Energy,
1986d).
3. Crystalline rocks - following a survey of crystalline rocks largely in the
regions of the Appalachian Mountains and the North American Shield, 12
areas in Georgia, North Carolina, Virginia, New Hampshire, Maine,
I
' Seismic-risk zone 3 corresponds approximately to the east and west province margins, where extension is most active.
Minnesota, and Wisconsin were recommended for further study (OCRD,1983;
U.S. Department of Energy, 1986e).
4. Sedimentary rocks - widely distributed claystones and shales were considered
as appropriate media for geologic disposal of nuclear waste by the National
Academy of Sciences (1957). DOE supported several investigations in this
medium (Merewether et al., 1973; Shurr, 1977; Dames and Moore, 1978; and
Brookins, D.G., 1986b)
5. Tuffaceous rocks, Nevada Test Site - included tuffs in both the unsaturated
and saturated zones that had been examined in considerable detail as part of
other investigations on the Test Site (U.S. Department of Energy, 1986f,g).
This site received the endorsement of USGS Director McKelvey, who wrote
to DOE in 1976 pointing out the remoteness of the site, its varied geologic
environments, and the existence of 900 man-years of data collection and
interpretation.
Throughout the 1970s and 1980s, in addition to working with DOE in specific
areas, the USGS was tasked by Congress to study and comment on the problem of
disposal of high-level radioactive waste. A report released in 1978 concluded that (1) salt
was less than ideal as a disposal medium, (2) shales, tuffs, and crystalline rocks should be
considered, (3) major studies of flow and transport were needed, especially in fractured
rock, (4) more tools were needed for dating water and materials older than about 40,000
years, and (5) the severe limitations of Earth science predictions needed to be recognized
(Bredehoeft et al., 1978).
In 1980, the Office of Nuclear Waste Management of DOE and the USGS of the
Department of Interior (DOI) released jointly a draft plan for disposal of radioactive
waste in a mined repository (U.S. Department of Energy and U.S. Geological Survey,
1980). The report was written by 17 scientists from five organizations and concluded
that there was a need to redirect research from generic characterization to four or five
specific sites, that detailed study plans should be prepared for each site, and that research
and developn~ent at the current level should be sufficient to resolve major technical issues
within the next 10 years. They also noted a need for research on thermo-mechanical
effects on hydrology. The search for more specific sites was started in 198 1, when the
USGS, in cooperation with seven State agencies (Arizona, California, Idaho, Nevada,
New Mexico, Texas, and Utah), .began evaluating the Basin and Range Province for
possible repository sites. The results were published in eight Professional Papers in the
1370 series; the region encompassing Yucca Mountain is described by Bedinger et al.
(1 989).
THE YUCCA MOUNTAIN SITE
The Yucca Mountain site is located in Nye County in southern Nevada,
approxin~ately 160 km (1 00 mi) northwest of Las Vegas (fig. 1). The entire proposed
repository is located on Federal lands, a principal consideration in facilitating further
study. The eastern portion is located on the Nevada Test Site; the northwestern comer is
located on the Nevada Test and Training range of the U.S. Air Force; and the
southwestern corner is located on land managed by the Bureau of Land Management.
Scientific investigations began at Yucca Mountain at the end of the 1970s. The
area had already been mapped at 1 :24,000 (Lipman and McKay, 1965; Christiansen and
Lipman, 1965), and the geology was known to be uncomplicated. The gently dipping
volcanic strata of fairly uniform thickness over a large area could be characterized easily,
and Yucca Mountain was well removed from the region of active nuclear weapons
testing. Initial efforts focused on the saturated zone, but preliminary drilling showed that
the water table was very deep (nearly 600 m), the temperature at the water table was
moderately elevated (30-35"C), and the rocks in the saturated zone were highly
trans~nissive, making containment of any leaked waste difficult if not impossible.
The general benefits of an unsaturated zone had already been pointed out by
Winograd (1 974, 198 l), including greater ease of (1) characterizing the site, (2)
monitoring stored waste, and (3) retrieving waste should it become necessary. In
February of 1982, USGS geologists indicated in a letter to DOE that the thick unsaturated
zone at Yucca Mountain might offer considerable advantages for disposing of radioactive
waste. The rationale was that only a small amount of water would reach the underground
reposito~y, and the repository could be designed so as to permit this water to pass through
into deeper permeable rocks and thus have only minimal contact with the stored waste
containers. Furthermore, there was a thick zeolitic unit above the water table that would
impede the movement of water to the saturated zone and sorb several of the radioactive
elements should there be any leakage. A more complete discussion of the advantages on
the unsaturated zone at Yucca Mountain is presented by Roseboom (1983). In July of
1982, DOE changed the target horizon for a possible repository to the unsaturated zone.
At the end of 1982, the focus of high-level radioactive waste disposal changed
with the passage of the Nuclear Waste Policy Act (NWPA), which directed DOE to
develop specific criteria for recommending candidate sites and prohibited
characterization work at any site until a site-characterization plan had been developed.
Work at Yucca Mountain was allowed to continue because it was already in progress.
DOE developed siting criteria, which were published as 10 CFR 960 (U.S. Department of
Energy, 1984c), and nine sites were selected for judging against the siting criteria. By
1986, three sites remained: a bedded salt at Deaf Smith, Texas; the basalt flows of
Hanford, Washington; and the ash-flow tuffs of Yucca Mountain, Nevada. At the end of
1987, Congress amended the Nuclear Waste Policy, Act, directing DOE to characterize
only Yucca Mountain.
The designation of Yucca Mountain as the only site for continued study was
based on several important factors. It is located at the west edge of the Nevada Test Site,
an area in which many years of geologic, geophysical, hydrologic, and related
investigations had been conducted in support of the underground nuclear weapons testing
program, as well as preliminary studies of various parts of the area as potential nuclear-
waste disposal sites. The preliminary studies had illuminated several favorable
conditions for siting a geological repository as noted previously, and no major adverse
conditions had been found. However, DOE was instructed to notify Congress
immediately and to stop work if anything was discovered that made the site unsuitable.
Hydrologic conditions in both the saturated and unsaturated zones were of major
importance in the designation of Yucca Mountain as the only site to be characterized.
These will be discussed in a companion volume. A series of papers covering aspects of
both zones can be found in Bodvarsson et al. (2003), and a description of the regional
flow system can be found in D'Agnese et al. (2002).
DOE, as directed by the NWPA, developed an extensive Site Characterization
Plan (U.S. Department of Energy, 1988), and the details of how characterization was to
proceed were written into more than 100 study plans. Studies included regional and site
geology, volcanic stratigraphy, Quaternary deposits, climate and paleoclimate, erosion,
unsaturated zone hydrology, saturated zone hydrology, mineralogy and petrology, rock
and fluid geochemistry, fracture fillings characterization, rock mechanics, thermal
testing, coupled processes testing, radionuclide transport, tectonics and tectonic models,
seismic and volcanic hazards analysis, geophysics, and natural resources evaluation.
Some of the results of these investigations are discussed in the following chapters of this
volunle. Combined, the results of the entire suite of investigations provide ample
docunlentation that Yucca Mountain is one of the most thoroughly studied geologic
features on Earth. Each of these subjects is discussed in detail in the Site Description
(Bechtel SAIC Company, 2004). This publication will discuss the regional and site
geology, tectonics, and climate (past, present, and future).
REGULATORY INFORMATION
The Yucca Mountain project has been one of the most heavily regulated and scrutinized
projects in the history of geology. This section provides a brief overview of this aspect of
the project. The NWPA of 1982 ( I ) established a comprehensive national policy for
management and disposal of spent nuclear fuel and high-level radioactive waste, which
still remains the framework for the Nation's geologic disposal program; and (2)
designated three agencies with the authority and responsibility related to waste disposal:
(a) DOE, for siting, licensing, constructing, operating, and closing a repository; (b) the
U.S. Environmental Protection Agency, for developing and issuing standards for
radiological release from a repository; and (c) the Nuclear Regulatory Commission
(NRC), for establishing requirements and criteria for approving or disapproving a license
for a repository. The NWPA also established a fund derived from a 1.0 mil per kilowatt-
hour assessment on electricity generated by nuclear powerplants. This h n d would cover
costs associated with site characterization, licensing, and operation of a repository (with
some additional funding from the Department of Defense for handling of their radioactive
waste).
The NWPA also provided for use of the nuclear waste fund in the form of grants
for monitoring and independent characterization.activities by the State in which site
characterization was active as well as monitoring by other affected governmental
agencies and affected Indian tribes. In addition, funds have been made available to the
NRC for the same purposes. The NWPA required DOE to provide Congress with annual
reports on all site-characterization activities and findings.
The Nuclear Waste Policy Amendments Act added another layer of oversight by
creating the U.S. Nuclear Waste Technical Review Board. The 11 members of this board
are appointed by the President from a slate of nominees provided by the National
Academy of Sciences. The Board was also given investigatory powers by the Act.
A rigorous Quality Assurance (QA) program provides an internal oversight of all
Project work. All scientific activities must conform to several standards. Among these
are the following: Each activity must be fully described in a planning document before
any data collection can take place. The rationale as to why the study is needed is given.
The methods to be used are listed used along with an explanation of how these methods
will attain the desired answers or what should be done if unexpected results are found.
All personnel performing quality-affecting work must have their qualifications
documented and verified, and their training must be documented. Procurements
supporting quality-affecting work must be reviewed for appropriate QA requirements and
be procured from approved sources that are audited. All instruments to be used must be
calibrated; the tolerances for calibration must be given, and all calibrations must be
within the tolerance limits or else the data are discarded back to the date of the last
known acceptable calibration. All data are collected according to detailed written
procedures, and all samples are controlled and tracked. Finally, all data and records are
reviewed and entered into a project data base. Any part of the QA program is subject to
internal audit and/or audit by the NRC.
The NRC, in 10 CFR 63, mandated that the license application for the Yucca Mountain
site include a computer model that will assess how the engineered and natural systems, as
a whole, will act to isolate radionuclides from the accessible environment. All data
collected by the project have been synthesized into subsystem models and abstracted into
a Total System Performance Assessment (TSPA). Much of the data in this volume are
included in process models that form the basis for TSPA, either as frameworks within
which a model must operate (e.g., the basic geologic data for the site) or as input to a
model (e.g., future climate as an input to future unsaturated-zone flow and transport). For
a nlore comprehensive discussion of this complicated model and its results see Bechtel
SAlC Con~pany (2003).
Figure Captions
Figure 1 .-Map showing the location of the proposed repository at Yucca Mountain, Nevada.
REFERENCES CITED
Alexander, D.H., and Van Luik, A.E., 1991, natural analogue studies useful in validating
regulatory compliance analyses, in Validation of geosphere flow and transport models
(GEOVAL): Proceedings of a NEAJSKI Symposium, stockholm, Sweden, May 14-
17, 1990, Paris, France, Organization for Economic Cooperation and Development, p.
589-597.
Bechtel SAIC Con~pany, 2003, Total system performance assessment--license application
methods and approach: Las Vegas, Nevada, Bechtkl SAIC Company, TDR-WIS-
PA-000006 REV 00 ICN 0 1.
Bechtel SAIC Con~pany, 2004, Yucca Mountain site description: Las Vegas, Nevada,
Bechtel SAIC Company, TDR-CRW-GS-000001 REV 02 ICN 01, Two volumes.
Bedinger, M.S., Sargent, K.A. and Langer, W.H., 1989, Studies of geology and
hydrology in the Basin and Range Province, southwestern United States, for isolation
of high-level radioactive waste - Evaluation of the regions: U.S. Geological Survey
Professional Paper 1370-F, 8 plates and 49 p.
Bodvarsson, G.S., Ho, C.K., and Robinson, S.A., eds., 2003, Yucca Mountain Project:
Journal of Contaminant Hydrology, v. 62-63, 750 p.
Bredelloeft, J.D., England, A.W., Stewart, D.B., Trask, N.J., and Winograd, I.J., 1978,
Geologic disposal of high-level radioactive wastes - Earth-science perspectives:
U.S. Geological Survey Circular 779, 15 p.
Brookins, D.G., 1986a, Natural analogues for radwaste disposal - elemental migration
in igneous contact zones: Chemical Geology, v. 55, p. 337-344.
Brookins, D.G., 1986b, Proceedings of the First Geochemical Workshop on Shale:
Martin Marietta, Oak Ridge National Laboratory, ORNLITM-9865.
Christiansen, R.L., and Lipman, P.W., 1965, Geologic map of the Topopah Spring NW
quadrangle, Nye County, Nevada: U.S. Geological Survey Geologic Quadrangle
Map GQ-444, scale 1 :24,000.
Cowley, K.D., 1997, Nuclear waste disposal - the technical challenges: Physics Today,
June 1997, p. 32-39.
D'Agnese, F.A., O'Brien, G.M., Faunt, C.C., Belcher, W.R., and San Juan, C., 2002, A
three-dimensional numerical model of predevelopment conditions in the Death
Valley regional ground-water flow system, Nevada and California: U.S.
Geological Survey Water-Resources Investigations Report 2002-4102, 114 p.
Dan~es and Moore, 1978, Baseline rock properties - Shale: Office of Waste Isolation,
Report Y/OWI/TM-3616.
Dyer, J.R., and Voegel, M.D., 2001, The Yucca Mountain site characterization project for
the United States, in Witherspoon, P.A, and Bodvarsson, G.S., eds., Geological
challenges in radioactive waste isolation - Third worldwide review: Lawrence
Berkeley National Laboratory Report LBNL-49767, Berkeley, California, p. 298- -
312.
Ekren, E.B., Dinwiddie, G.A., Mytton, J.W., Thordarson, W., Weir, J. E., Jr., Hinrichs,
E.N., and Schroder, L.J., 1974, Geologic and hydrologic considerations for various
concepts of high-level radioactive waste disposal in conterminous United States:
U.S. Geological Survey Open-File Report 74- 158, 2 19 p.
Lipman, P.W., and McKay, E.J., 1965, Geologic map of the Topopah Spring SW
quadrangle, Nye County, Nevada: U.S. Geological Survey Geologic Quadrangle
Map GQ-439, scale 1 :24,000.
Merewether, E.A., Sharpe, J.A., Gill, J.R., and Cooley, M.E., 1973, Shale, mudstone and '
claystone as potential host rocks for underground emplacement of waste: U.S.
Geological Survey Open-File Report 73-1 84,44 p. plus maps.
Miller, W., Alexander, R., Chapman, N., McKinley, I., and Smellie, J., 1994, Natural
analogue studies in the geological disposal of radioactive wastes: Amsterdam,
Elsevier, 328 p.
National Research Council, 1957, The disposal of radioactive waste on land: Report of
the Committee on Waste Disposal of the Division of Earth Sciences, National
Research Council, National Academy of Sciences, Publication 5 19, 42 p.
Nuclear Energy Agency, 1995, The environmental and ethical basis of geological disposal,
a collective opinion of the NEA Radioactive Waste Management Committee: Paris,
Organization for Economic Co-operation and Development, 30 p.
OCRD, 1983, A national survey of crystalline rocks and recommendations of regions to
be explored for high-level radioactive waste repository sites: Columbus, Ohio,
Battelle Memorial Institute, Office of Crystalline Repository Development (OCRD),
OCRD-1, 110 p.
Roseboom, E.H., Jr., 1983, Disposal of high-level waste above the water table in arid
regions: U.S. Geological Survey Circular 903, 21 p.
Shi~rr, G.W., 1977, The Pierre Shale, northern Great Plains -- A potential isolation
nledium for radioactive waste: U.S. Geological Survey Open-File Report 77-776, 27
P.
Stuckless, J.S., 2000, Archaeological analogues for assessing the long-term performance
of a mined geologic repository for high-level radioactive waste: U.S. Geological
Survey Open-File Report 2000- 18 1,27 p.
Stuckless, J.S., 2002, Natural analogues -- One way to help build public confidence in the
predicted performance of a mined geologic repository for nuclear waste: Waste
Management 2002 symposium, Tucson, Arizona, 15 p.
U.S. Department of Energy and U.S. Geological Survey, 1980, DOE Office of Nuclear
Waste Management and US Geological Survey, Earth science technical plan for
disposal of radioactive waste in a mined repository (Draft): DOEITIC-11033 (draft)
and USGS (draft report), 21 1 p. (available from National Technical Information
Service, Springfield, VA)
U.S. Department of Energy, 1984a, Environmental assessment overview Cypress Creek
Dome, Mississippi: OCRWM, DOEJRW-00 1 1, 26 p.
U.S. Department of Energy, 1984b, Environmental assessment overview Swisher County
Site, Texas: OCRWM, DOEJRW-0015,26 p.
U.S. Department of Energy, 1984c, General guidelines for the recommendation of sites
for the nuclear.waste repositories; final siting guidelines: 10 CFR 960.
U.S. Department of Energy, 1986~1, Environmental assessment overview for Richton
Dome, Mississippi: OCRWM, DOEIRW-0078, 37 p.
U.S. Department of Energy, 1986b, Environmental assessment overview for Deaf Smith
County Site, Texas: OCRWM, DOEIRW-0075, 36 p.
U.S. Departn~ent of Energy, 1986c, Environmental assessment overview for Davis
Canyon Site, Utah: OCRWM, DOEIRW-0077,38 p.
U.S. Department of Energy, 1986d, Environmental assessment overview for reference
repository location, Hanford Site, Washington: OCRWM, DOEIRW-0076, 34 p.
U.S. Department of Energy, 1986e, Area recommendation report for the Crystalline
Repository Project: OCRWM, DOEICH-15(1), volume 1.
U.S. Department of Energy, 1986f, Environmental assessment, Yucca Mountain Site,
Nevada Research and Development Area, Nevada: OCRWM, DOEIRW-0073,3
volumes.
U.S. Department of Energy, 19868, Environmental assessment overview for Yucca
Mountain Site, Nevada Research and Development Area, Nevada: OCRWM,
DOEIRW-0079, 36 p.
U.S. Department of Energy, 1988, Site Characterization Plan, Yucca Mountain Site,
Nevada Research and Development Area, Nevada: OCRWM, 9 volumes.
U.S. Department of Energy, 2001, Yucca Mountain science and engineering report:
OCRWM, DOEJRW-0539, section l , 4 5 p.
Winograd, I.J., 1974, Radioactive waste storage in the arid zone: EOS, v. 55, p. 884-894.
Winograd, 1 .J., 198 1, Radioactive waste disposal in thick unsaturated zones: Science, v.
212, p. 1457-1464.
Winograd, I.J., 1986, Archaeology and public perception of a transscientific problem --
Disposal of toxic wastes in the unsaturated zone: U.S. Geological Survey Circular
990,9 p.
Acknowledgments
All of the authors of this memoir have been supported by the Department of Energy
(DOE), Office of Civilian Radioactive Waste Management. All of the research reported
here, except for most of the regional geology, also has been supported by DOE. Ardyth
Simmons (Los Alamos National Laboratory) was instrumental in creating the impetus for
publishing this work. The authors of this chapter wish to thank Eugene Roseboom and
Isaac Winograd (U.S. Geological Survey, retired), Michael Voegele (Science Application
Inter~~ational Corporation, retired), and Claudia Newbury (DOE), who collectively have
more than a century of work in high-level radioactive waste disposal, for very helpful
reviews and many helpful discussions.