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1
Introduction and Task
The Hanford Site was established by the federal government in
1943 as part of the secret wartime effort to produce plutonium for nuclear
weapons. The site operated for about four decades and produced roughly
two thirds of the 100 metric tons of plutonium in the U.S. inventory.
Millions of cubic meters of radioactive and chemically hazardous wastes,
the by-product of plutonium production, were stored in tanks and ancillary
facilities at the site or disposed or discharged to the subsurface, the
atmosphere, or the Columbia River.
In the late 1 980s, the primary mission of the Hanford Site
changed from plutonium production to environmental restoration. The
federal government, through the U.S. Department of Energy (DOE),
began to invest human and financial resources to stabilize and, where
possible, remediate the legacy of environmental contamination created by
the defense mission. During the past few years, this financial investment
has exceeded $1 billion annually. DOE, which is responsible for cleanup
of the entire weapons complex, estimates that the cleanup program at
Hanford will last until at least 2046 and will cost U.S. taxpayers on the
order of $85 billion (DOE, 1 998e).4
Although the "final" condition of the site (i.e., the condition of the
site when the cleanup program is complete) has not yet been agreed
upon by DOE, its regulators, and other interested parties, work is in
progress to stabilize waste and restore the environment so that parts of
the site can be released for other uses. After DOE cleanup is completed,
however, large areas of subsurface contamination will still remain at the
site, including groundwater contamination, and there will be large burial
grounds that contain waste from both the defense and the cleanup
missions. The cost and duration of the cleanup effort cited above do not
account for the long-term investments that will be required to manage
these contaminated areas until they no longer pose a hazard to humans
or the environment.2
One of the most difficult cleanup problems at the Hanford Site
involves remediation of the underground high-level waste storage tanks
Life-cycle cost estimate fully escalated to year of expenditure. The estimated
life-czycle cost in constant fiscal year 1998 dollars is about $51 billion.
The report Long-Term Institutional Management of U.S. Department of
Energy Legacy Waste Sites (National Research Council, 2000c) discusses these
long-term management challenges. See also From Cleanup to Stewardship
(DOE, 1 999f) and A Report to Congress on Long-Term Stewardship (DOE, 2001~.
6
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Introduction and Task
and the underlying soil and grounclwater in the 200 Area (see Chapter 2~.
There are 177 underground storage tanks at the site, which collectively
contain about 54 million gallons of high-level waste generated from
plutonium separation processes. According to DOE, 67 of these tanks are
known or suspected to have leaked high-level waste into the subsurface,
and it is now recognized that some of this leaked material has reached
groundwater.
Part of the motivation for this National Research Council (NRC)
study grew out of suggestions that the subsurface migration of
radionuclides that leaked from these tanks was more extensive than had
been predicted (see DOE [1997b] for details). It had been predicted that
most radionuclides from these tank leaks would be effectively sorbed onto
minerals contained in the subsurface sediments, thereby retarding their
migration to groundwater. This assessment appeared to be supported by
numerical models developed to predict radionuclide transport beneath the
tanks.
Such predictions were called into question, however, by actual
measurements of radionuclide (cesium-137) distributions in boreholes
around and beneath the tanks in the SX Tank Farm beginning in 1994
(DOE, 1996~. These measurements suggested that cesium-137 had
migrated greater than 38 meters (125 feet) beneath the SX Tank Farm
(DOE, 1 998a, pp. 4.50-4.52~.3 Although the actual extent of deep
radionuclide migration and the mechanisms for such migration remain
unclear (DOE, 1 997b), such observations have fueled public concerns
and drawn attention to Hanford vadose zone issues in high levels of
government (GAO, 1998~.
Indeed, this discovery received a great deal of attention by the
media and prompted congressional inquiries and a General Accounting
Office investigation (GAO, 1998~. In response, and with the strong
encouragement of DOE Headquarters, Hanford Site management
established the Groundwater/\/adose Zone Integration Project in 1997 to
coordinate and provide scientific and technical support for waste
management and cleanup efforts under way at the site.
The Integration Project was created through a memorandum of
understanding among three preexisting organizations at the Hanford Site
(see Chapter 3) and is being led by Bechtel Hanford, Inc., with oversight
from DOE. The project was established with the following five objectives
(DOE, 1 998d, p. 1 .1 ):4
3Subsequently, technetium-99 was detected in the groundwater beneath
these and other tank farms in the 200 East Area (PNNL, 1999, p. 6.38; DOE,
1998, p. 4-50~.
4The objectives given here are direct quotes from DOE (1 998d). These
objectives have been reworded in a subsequent document (DOE, 2000a).
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8
Science and Technology for Environmental Cleanup
1. Integrate all Hanford Site GWNZ
[groundwater/vaclose zone] related work scope.
2. Predict current and future impacts resulting
from contaminants that have been (or are predicted to
be) released to the soil column at the Hanford Site.
3. Provide a sound science and technology (S&T)
basis for site decisions and actions.
4. Promote open and honest involvement of
Tribal Nations, regulators, and stakeholders so that
project outcomes reflect expressed interests and values.
5. Establish an independent technical peer
review.
As discussed in more detail in Chapter 3, the Integration Project
is responsible for developing and conducting assessments to determine
the effects of chemical and radioactive contaminants on groundwater, the
Columbia River, and users of the river's resources. The project is not
directly responsible for waste management or cleanup activities at the
site. These tasks are the responsibility of the three Hanford Site
organizations that signed the memorandum of understanding that gave
rise to the Integration Project.
At the request of DOE Headquarters, two technical teams were
established to provide peer review of Integration Project activities as
called for in the fifth program objective: The Integration Project Expert
Panel (IPEP)5 was created in 1998 to provide advice and
recommendations on key programmatic, technical, and administrative
issues affecting the success of the Integration Project. This group has
been meeting quarterly and has issued several reports that address
various aspects of the integration effort at the site.6 In addition, the
Assistant Secretary for Environmental Management requested that the
National Research Council review the science and technology S&T
program established under the auspices of the Integration Project as
called for by the third program objective. That request led to the current
study, the results of which are summarized in this report.
51PEP consists of eight technical experts: Edgar Berkey, chair, and members
Randy Bassett, John Conaway, James Karr, Michael Kavanaugh, John Matuszek,
Ralph Patt, and Peter Wierenga.
6The expert panel's reports are available on-line at http://www.bhi-erc.com/
projects/vadose/peer/ipep.htm.
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Introduction and Task
9
SCOPE OF THIS STUDY
The NRC was asked to review the S&T program and to provide
recommendations to improve its technical merit and relevance to DOE's
remediation decisions, with particular attention to the following issues:
· the technical merit of the S&T work to be carried out under
the program, including its likely contribution to advancing the state of
scientific knowledge;
. the relevance and timeliness of the planned S&T work to
DOE remediation decisions at the Hanford Site; and
· the potential applicability of S&T results to contamination
problems at other DOE sites.
The chair of the National Research Council appointed a
committee of 14 experts (Appendix A) to undertake this study. The
committee met six times to gather information, deliberate on the issues,
and develop this report. Three meetings were held in Richland,
Washington, near the Hanford Site, so that the committee could receive
briefings from DOE staff and site contractors, obtain comments from
interested stakeholders, and tour the Hanford Site to see first-hand the
cleanup activities and ongoing scientific work. A list of briefings received
by the committee at its meetings is provided in Appendix B.
REPORT CONTENT AND ORGANIZATION
The committee's review of the Integration Project's S&T program
is organized as follows: Chapters 2 and 3 provide background information
on the Hanford Site and the Integration Project. Chapter 4 provides a
discussion of the System Assessment Capability, an Integration Project-
developed risk assessment tool to estimate quantitative effects of
contaminant releases. Chapters 5 through 9 provide reviews of the
technical elements of the science and technology program, and Chapter
10 provides programmatic-level recommendations.
The S&T program is at an early stage of development the draft
program plan (DOE, 1998d) was completed in fiscal year 1998, and
funding for scientific work was provided beginning in fiscal year 1999. As
a result, many aspects of the program exist only on paper, and there is
relatively little scientific output on which to judge program effectiveness. In
fact, as noted repeatedly in subsequent chapters, detailed written plans in
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10
Science and Technology for Environmental Cleanup
individual S&T projects do not exist for many elements of the program,
although there are a few notable exceptions.7
Consequently, the reviews of the S&T program elements that
are provided in this report are based primarily on committee
members' general knowledge and understanding of relevant
scientific and engineering disciplines and Hanford Site problems.
Except as noted explicitly in the following chapters, none of the
committee's comments should be construed as an endorsement of
specific individual projects. Rather, the committee's comments
address general directions of the SOT program and the apparent
appropriateness of program priorities.
The committee has adopted a long-term perspective in its review
of this program In recognition of the fact that the DOE clean up program is
likely to last for several decades. Even then, there will be a need for
continuing management of residual contamination. Consequently, there
will be a need for S&T beyond that required to meet near-term milestones
and regulatory requirements. Indeed, the S&T work is likely to continue
for many years and, if done well, could substantially and positively impact
cleanup decisions at the site.
J
7Primarily the S&T work under the auspices of the Vadose Zone Technical
Element, for which detailed planning documents are available (see Chapter 6~.
Representative terms from entire chapter:
integration project
