Nuclear Waste: Understanding of Waste Migration at Hanford is Inadequate
for Key Decisions (Letter Report, 03/13/98, GAO/RCED-98-80).
Pursuant to a congressional request, GAO reviewed the Department of
Energy's (DOE) efforts to develop an understanding of conditions in the
vadose zone, focusing on: (1) the adequacy of DOE's current
understanding of the extent to which waste materials are moving through
the vadose zone; and (2) DOE's current strategy for investigating vadose
zone conditions.
GAO noted that: (1) DOE's own reviews conclude what outside experts have
been saying for some time; (2) DOE's understanding of how wastes move
through the vadose zone to the groundwater is inadequate to make key
technical decisions on how to clean up the wastes at the Hanford Site in
an environmentally sound and cost-effective manner; (3) for many years,
DOE assumed that wastes would move slowly, if at all, through the vadose
zone; (4) therefore, DOE never issued a comprehensive plan to assess
vadose zone conditions and funded few studies of the vadose zone; (5)
outside experts have pointed out, however, that DOE cannot credibly
estimate the site's long-term risk to the public or select the most
efficient cleanup strategies unless it understands conditions in the
vadose zone; (6) for example, the lack of knowledge about the vadose
zone has major implications for how to go about retrieving the remaining
wastes from tanks that have leaked or are leaking because at least one
retrieval option would cause more liquid wastes to leak into the ground;
(7) DOE has no strategy in place for investing the vadose zone; (8) DOE
assigned low funding priority to most proposed studies of it, responded
slowly to experts' recommendations for improving ongoing studies, did
not integrate the information needs of the three organizational units
responsible for cleanup activities, and does not know what information
is needed to make key cleanup decisions; and (9) with the emerging
evidence of waste migration from leaking tanks to the groundwater, DOE
has begun to develop a strategy to investigate the vadose zone.
--------------------------- Indexing Terms -----------------------------
REPORTNUM: RCED-98-80
TITLE: Nuclear Waste: Understanding of Waste Migration at Hanford
is Inadequate for Key Decisions
DATE: 03/13/98
SUBJECT: Hazardous substances
Nuclear waste storage
Environmental research
Radiation exposure hazards
Tanks (containers)
Water pollution control
Environmental monitoring
Nuclear waste management
Nuclear waste disposal
IDENTIFIER: DOE Vadose Zone Program
DOE Hanford Future Site Uses Study
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Cover
================================================================ COVER
Report to Congressional Requesters
March 1998
NUCLEAR WASTE - UNDERSTANDING OF
WASTE MIGRATION AT HANFORD IS
INADEQUATE FOR KEY DECISIONS
GAO/RCED-98-80
Nuclear Waste
(141058)
Abbreviations
=============================================================== ABBREV
CERLCA - Comprehensive Environmental Response, Compensation, and
Liability Act of 1980
DOE - Department of Energy
EPA - Environmental Protection Agency
GAO - General Accounting Office
RCRA - Resource Conservation and Recovery Act of 1976
TWRS - Tank Waste Remediation System
Letter
=============================================================== LETTER
B-279142
March 13, 1998
The Honorable John Glenn
Ranking Minority Member
Committee on Governmental Affairs United States Senate
The Honorable Ron Wyden
United States Senate
In December 1997, the Department of Energy (DOE) announced that
highly radioactive wastes at the Hanford Site in southeastern
Washington State from previously leaking underground storage tanks
had migrated through the soil and rocks to the underlying
groundwater. DOE had previously believed that the area above the
water table--called the vadose zone--was an effective barrier between
the tank wastes and the groundwater.
Concerned about the potential risk of both radioactive and hazardous
chemical wastes at the Hanford Site to populations downstream from
the nearby Columbia River, you asked us to review DOE's efforts to
develop an understanding of conditions in the vadose zone. As agreed
with your offices, we focused our review on the following questions:
-- How adequate is DOE's current understanding of the extent to
which waste materials are moving through the vadose zone?
-- How adequate is DOE's current strategy for investigating vadose
zone conditions?
We directed much of our review on wastes that have leaked from
storage tanks and, to a lesser extent, on the effects that other
programs and activities at the site have had on the vadose zone.
RESULTS IN BRIEF
------------------------------------------------------------ Letter :1
DOE's own reviews conclude what outside experts have been saying for
some time: The Department's understanding of how wastes move through
the vadose zone to the groundwater is inadequate to make key
technical decisions on how to clean up the wastes at the Hanford Site
in an environmentally sound and cost-effective manner. For many
years, DOE assumed that wastes would move slowly, if at all, through
the vadose zone. Therefore, DOE never issued a comprehensive plan to
assess vadose zone conditions and funded few studies of the vadose
zone. Outside experts have pointed out, however, that DOE cannot
credibly estimate the site's long-term risk to the public or select
the most efficient cleanup strategies unless it understands
conditions in the vadose zone. For example, the lack of knowledge
about the vadose zone has major implications for how to go about
retrieving the remaining wastes from tanks that have leaked or are
leaking because at least one retrieval option would cause more liquid
wastes to leak into the ground.
DOE has no strategy in place for investigating the vadose zone. DOE
assigned low funding priority to most proposed studies of it,
responded slowly to experts' recommendations for improving ongoing
studies, did not integrate the information needs of the three
organizational units responsible for cleanup activities, and does not
know what information is needed to make key cleanup decisions. With
the emerging evidence of waste migration from leaking tanks to the
groundwater, DOE has begun to develop a strategy to investigate the
vadose zone.
BACKGROUND
------------------------------------------------------------ Letter :2
DOE's Hanford Site is located in southeastern Washington State. The
Columbia River flows in a southeastern direction through the northern
part of the site and forms much of its eastern boundary. (See fig.
1.) As of 1995, about 175,000 people lived immediately downstream in
and near the cities of Kennewick, Pasco, and Richland.
Figure 1: Location of the
Hanford Site
(See figure in printed
edition.)
Source: Based on a map provided by DOE.
At the Hanford Site, DOE and its predecessor agencies produced
materials for nuclear weapons from the 1940s until mid-1989. DOE
estimates that these production activities resulted in about 450
billion gallons of liquid waste. DOE released most of this waste
directly into the ground through about 300 cribs,\1 ponds, and
trenches that are now awaiting final cleanup. The groundwater under
more than 85 square miles of the site is contaminated above current
standards.
DOE is storing about 54 million gallons of the most radioactive and
hazardous wastes in 177 underground tanks pending permanent disposal.
Of the 177 tanks, 149, called single-shell tanks, have a single layer
of carbon steel encased inside a concrete outer wall, while 28
double-shell tanks have two layers of carbon steel inside the
concrete casing. The tanks, arranged in groups or "farms" of several
tanks, and most of the cribs, ponds, and trenches are located in the
"200 East" and "200 West" areas at the center of the Hanford Site.
(See fig. 1.) Beneath the 200 areas, the vadose zone is between 200
and 300 feet thick and is made up of sand, silt, and gravel above a
layer of volcanic rock. (See fig. 2.)
Figure 2: Waste Migration
Through the Vadose Zone at the
Hanford Site
(See figure in printed
edition.)
Source: Based on an illustration from DOE.
Over time, many of the single-shell tanks developed leaks--DOE
currently assumes that 67 tanks have leaked between 600,000 and
900,000 gallons of wastes.\2 Radioactive materials that have leaked
include cesium, strontium, tritium, technetium, iodine, plutonium,
and uranium. Some of these materials remain radioactive for hundreds
of thousands of years. Nonradioactive but hazardous materials that
have leaked include nitrates and metals such as chromium.
The Hanford Site's approximately 14,000 employees are now primarily
monitoring and cleaning up the radioactive and hazardous wastes
generated by the previous production of nuclear weapons materials.
Cleaning up the wastes stored in the single- and double-shell tanks,
a project that DOE calls the Tank Waste Remediation System (TWRS), is
the largest and most technically complex environmental project DOE
has attempted. DOE's most recent estimate, made in 1998, is that it
will cost about $50 billion (in current dollars) to retrieve the
wastes from the tanks, separate the wastes into low-level and
high-level portions, and prepare the low-level wastes for disposal at
the site and the high-level wastes for disposal in a geologic
repository.\3 In fiscal year 1997, the TWRS program cost about $314
million.\4
In fiscal year 1998, DOE expects to spend about $332 million on the
program.
Cleanup of the Hanford Site is being conducted under the Hanford
Federal Facility Agreement and Consent Order signed by DOE, the
Environmental Protection Agency (EPA), and the Washington State
Department of Ecology. This document, commonly called the Tri-Party
Agreement, established cleanup requirements for Hanford. For
example, in amendments agreed to in 1994, the three parties set a
goal of retrieving 99 percent of the wastes from single-shell tanks,
which are more susceptible to leakage. Under the agreement, DOE was
required to begin retrieving wastes from the first tank by October
31, 1997, and complete the retrieval of wastes from all single-shell
tanks by 2018.\5
Primary responsibility for cleaning up the Hanford Site, including
the vadose zone, is divided among three organizations within DOE's
Richland Operations Office. First, the TWRS project office is
responsible for managing and cleaning up the single- and double-shell
tanks, the related facilities such as piping systems, and the vadose
zone surrounding the tanks. Second, the Environmental Restoration
unit is responsible for cleaning up closed facilities and for the
vadose zone under the hundreds of inactive liquid waste disposal
facilities such as ponds, trenches, and cribs. Finally, the Waste
Management unit is responsible for stored and newly generated wastes
and related operational facilities, including the vadose zone under
these wastes and facilities. DOE's Assistant Secretary for
Environmental Management provides policy direction to each of these
three organizations.
Although cleanup of the site is not expected to be completed until
2048, many key cleanup milestones specified in the Tri-Party
Agreement occur much sooner. Some of these milestones include
starting retrieval by 1997 (a milestone that DOE did not meet),
permanently closing one single-shell tank by 2003, and closing the
remaining single-shell tanks by 2024. DOE must also finish the
investigation of all of the other waste sites (such as the cribs,
ponds, and trenches) by 2008 and any resulting remediation by 2018.
--------------------
\1 A crib is an underground structure designed to allow liquid wastes
to percolate to the soil.
\2 These amounts do not include recent estimates using a new approach
that found that leaks could be much higher on some tanks, nor does it
include the wastes lost due to surface spills and leaks in pipelines.
\3 Under the Nuclear Waste Policy Act of 1982, as amended, DOE is
investigating a site at Yucca Mountain, Nevada, for possible use as a
repository for permanent disposal of spent (used) fuel from civilian
nuclear power plants and the Department's high-level radioactive
wastes now stored at the Hanford Site and at sites in Idaho, New
York, and South Carolina.
\4 In total, DOE received about $1.1 billion for cleanup programs at
Hanford in fiscal year 1998. In addition to the TWRS program, funds
were allocated to the cleanup and monitoring of other waste sites and
removal of old facilities ($135 million), management of spent fuel
($152 million), facility deactivation ($129 million), and other
programs ($369 million). DOE also received an additional $115
million for its TWRS privatization program.
\5 DOE did not begin retrieving wastes from the first tank by the
required date. The Department requested an extension to November 30,
1998, from the Washington State Department of Ecology, which is the
lead regulator for the cleanup of the Hanford Site. The Department
of Ecology denied this request on February 12, 1998.
DOE'S UNDERSTANDING OF THE
VADOSE ZONE IS INADEQUATE FOR
MAKING KEY TECHNICAL DECISIONS
------------------------------------------------------------ Letter :3
The field investigations of the vadose zone that DOE has recently
performed led to the Department's December 1997 announcement that
some wastes had migrated from leaking storage tanks to the
groundwater. This finding invalidated the Department's long-held
position that the vadose zone would protect the groundwater. The
finding also prompted DOE to agree with independent experts that the
Department needs to improve its understanding of vadose zone
conditions to help it select safe, cost-effective cleanup strategies.
THE IMPORTANCE OF THE VADOSE
ZONE
---------------------------------------------------------- Letter :3.1
The vadose zone is an important component of a complex environment at
the Hanford Site. To clean up the site, DOE will have to make a
number of key technical decisions related to emptying and permanently
closing the tank farms and remediating the many cribs, ponds, and
trenches. Making these decisions will require DOE to demonstrate
that the residual contamination at the site does not present
unacceptable risks of increased pollution to the Columbia River or
harm to nearby residents. When existing containers, such as
single-shell tanks, fail, the vadose zone is the only remaining
barrier to groundwater contamination.
One illustration of the importance of understanding the vadose zone
can be seen in DOE's current plans for retrieving wastes from
single-shell tanks. DOE has transferred most of the pumpable wastes
from 119 of the 149 single-shell tanks into double-shell tanks, but
left behind are wastes that have solidified to the point that they
could not be pumped. As part of its effort to remove and treat 99
percent of the wastes in the single-shell tanks, DOE currently
proposes to use large volumes of water injected under pressure to
dissolve much of the remaining wastes so that they can be pumped from
the tanks. DOE estimates that this approach, called sluicing, could
allow as much as another 596,000 gallons of wastes to leak from the
tanks into the vadose zone.
DOE has assumed that leaks from sluicing operations averaging 4,000
gallons will occur. However, in commenting on DOE's waste retrieval
plans, the National Research Council (the principal operating agency
of the National Academies of Sciences and Engineering) noted that the
risks from additional leakage must be analyzed. Also, the Council
contends that an inadequate understanding of how wastes behave in the
vadose zone precludes rationally selecting a tank waste retrieval and
treatment alternative. DOE is planning to try approaches other than
sluicing that may have lower potential for creating additional leaks.
Proper understanding of the vadose zone is critical in moving ahead
on this issue. If the vadose zone allows very little of the
radioactive or hazardous wastes to reach the groundwater, cleanup
strategies that add to the amount of wastes in the ground, such as
sluicing leaking waste tanks, may not eventually lead to excessive
contamination of groundwater. However, if such materials can pass
through the vadose zone and into the groundwater with relative ease,
such strategies may be inappropriate.
Acquiring a better understanding of what is occurring in the vadose
zone would also help resolve questions about the appropriateness of
two ongoing activities at Hanford that might be contributing to
contamination of the vadose zone. First, DOE is covering underground
storage tanks with more gravel. According to studies funded by DOE,
the use of gravel allows rain and snow to drive leaked wastes toward
the water table. Second, DOE has proposed to slow down its program
to transfer liquid wastes from single-shell tanks into double-shell
tanks. DOE had expected to complete this program in 2000 but does
not now expect to complete the program until 2003. Washington State
regulators are concerned that additional wastes could leak into the
vadose zone before they can be pumped. (See app. II for details on
these ongoing activities.)
DOE HAS FOCUSED LIMITED
ATTENTION ON MONITORING
VADOSE ZONE ISSUES
---------------------------------------------------------- Letter :3.2
DOE's efforts to date to develop an understanding of conditions in
the vadose zone have been limited. First, according to the TWRS
vadose zone program manager, over the past several decades, DOE built
its waste disposal strategy on the assumption that the vadose zone
would prevent most wastes from migrating down to the groundwater
without setting up a program for determining whether its assumption
was correct. Second, according to officials of DOE and Washington's
Department of Ecology, there is no requirement in law--similar to
that for groundwater--for monitoring contamination of the vadose
zone.
ASSUMPTION THAT VADOSE
ZONE ACTS AS A BARRIER
-------------------------------------------------------- Letter :3.2.1
Early operations at the Hanford Site had assumed that wastes could be
disposed of in the soil and that most of the contaminants would
remain there. DOE estimates that it had disposed of over 350 billion
gallons of wastes directly into the cribs, ponds, and trenches in the
vadose zone beneath the 200 East and 200 West areas by the time it
stopped this practice. As late as 1996, DOE was developing tank farm
cleanup plans that were still based on the assumption that the vadose
zone would act as a barrier. For example, DOE stated in a 1996 draft
environmental impact statement for TWRS that certain contaminants,
such as cesium, were assumed to be largely immobile in the vadose
zone. In part on the basis of this assumption, DOE estimated that,
even if it did not remove any wastes from the underground tanks, some
of the wastes would still not reach the groundwater for more than
10,000 years after all of the tanks had eventually begun to leak.
Cautions and concerns raised by us and others about the possible
movement of materials through the vadose zone were largely set aside.
For example, in 1989, we reported that DOE faced a mounting body of
evidence indicating that its assumption about the immobility of
wastes in the vadose zone was incorrect and recommended that DOE
gather sufficient data to assess the risks from tank leaks.\6 The
next year, a review team, called the "Tiger Team" and composed of
technical specialists from DOE's headquarters and other locations
within its complex of nuclear sites, said that DOE's understanding of
the site's hydrology was too poor to guide remedial actions.
According to DOE's groundwater program manager, however, neither of
these reviews led DOE to assign proposed studies of the vadose zone
high enough priority to be funded.
Since the 1960s, DOE has monitored the vadose zone near the
single-shell tanks for the limited purpose of detecting and
estimating the size (in gallons) of leaks from the tanks. DOE used
probes to measure one type of radiation in the nearly 800 "boreholes"
that it drilled over the years through the sand and gravel in the
vadose zone in and around the tank farms. (Hundreds of other
boreholes are also located in and near many of the ponds, cribs, and
other waste sites.) The scope of this monitoring program, however,
did not include measuring how much of the wastes is moving in the
vadose zone, how fast the wastes are moving, and the identity of
specific radionuclides.
DOE also has a limited understanding of the behavior of contaminants
placed in hundreds of cribs, trenches, and other waste sites above
the groundwater. For example, DOE has not routinely monitored waste
sites other than the tank farms since 1988, and earlier monitoring of
these sites was limited and sporadic. In fiscal year 1996, DOE
analyzed some wells located near about 20 waste facilities and found
that wastes can continue to migrate long after facilities are no
longer used. In commenting on a draft of this report, DOE said that,
at the request of stakeholders, it has concentrated vadose zone
activities on liquid disposal sites along the Columbia River because
these sites pose the most immediate threat to the river. DOE also
said that most liquids discharged into cribs, ponds, and trenches
were in relatively dilute form and that less mobile contaminants are
retained in the soil.
Although DOE's monitoring of these other waste sites has been
limited, most of the contamination in the 200 areas comes from the
cribs, ponds, and trenches. According to DOE's project manager, the
Department has proposed some analysis of these waste sites with about
$800,000 allocated for fiscal year 1998. DOE's Grand Junction
(Colorado) Office has informally proposed extending its recent study
of the vadose zone under the single-shell tank farms to include many
of these other waste sites, but DOE has not funded this proposal.\7
--------------------
\6 Nuclear Waste: DOE's Management of Single-Shell Tanks at Hanford,
Washington (GAO/RCED-89-157, July 18, 1989).
\7 The team is using data from the approximately 800 existing
boreholes in the tank farms to establish a baseline of information
about contamination distributed in the vadose zone near the
single-shell tanks.
NO VADOSE ZONE REGULATORY
REQUIREMENTS
-------------------------------------------------------- Letter :3.2.2
DOE's lack of emphasis on developing an understanding of the vadose
zone conditions is also due to the absence of an explicit requirement
in law, regulation, or in the Tri-Party Agreement to investigate or
monitor the vadose zone. An official of Washington State's
Department of Ecology told us that it did not impose such a
requirement in the agreement because he believed no clear authority
exists for the agency to do so. In contrast, under the Resource
Conservation and Recovery Act (RCRA) of 1976, as amended, and the
Tri-Party Agreement, DOE is required to monitor groundwater in waste
site areas. Also, under the Comprehensive Environmental Response,
Compensation, and Liability Act (CERLCA) of 1980, as amended, where
relevant and appropriate, the groundwater must be cleaned up to meet
safe drinking water standards.
This situation may now be changing. Under the groundwater monitoring
requirements of RCRA, DOE has been assessing the quality of the
groundwater under three groups of single-shell tank farms (a total of
eight tank farms) to determine whether or not the tanks in these
farms are the sources of contamination detected in the groundwater.
The results of these assessments led DOE to conclude that wastes from
tanks that have previously leaked have migrated to the goundwater.
Therefore, in accordance with EPA's groundwater monitoring
regulations, DOE is beginning more detailed assessments of the extent
of contamination and potential treatment options. For these
assessments, the regulatory agency under RCRA--in this case
Washington's Department of Ecology--has the authority to require DOE
to, among other things, investigate conditions in the vadose zone and
develop a specific plan for a groundwater quality assessment program
at the site.
DOE'S RECENT FINDINGS ABOUT
THE VADOSE ZONE CONTRADICT
THE DEPARTMENT'S
LONG-STANDING ASSUMPTION
THAT IT ACTS AS A BARRIER
---------------------------------------------------------- Letter :3.3
Beginning in 1994, DOE's Grand Junction Office, using technology
developed to detect uranium ore deposits, performed tests in about
800 existing boreholes in the single-shell tank farms. These tests
were primarily intended to provide baseline information about the
distribution of certain radioactive wastes around the tanks.\8
However, the tests also enabled the Grand Junction team to identify
radioactive substances at considerable depths in the vadose zone.
DOE program managers said that this work has greatly enhanced DOE's
understanding of vadose zone conditions to a depth of 75 to 150 feet
and provided some information about conditions down to the
groundwater more than 200 feet beneath the land surface. In tank
farms where the Grand Junction team has completed its work, the team
has been able to develop visual representations of how contaminants
are distributed around the waste storage tanks. In addition, the
team found indications of possible new leaks in some tank farms and
deep contamination by some radionuclides in several farms.
The Grand Junction team's findings led Washington's Department of
Ecology to request DOE to assess whether contaminants had migrated
from a specific tank farm to the groundwater. In addition, since
1993 DOE had been conducting a similar assessment at three other tank
farms. At a November 1997 news conference, DOE released draft
reports confirming that groundwater testing at two groups of tank
farms had found that wastes from the tanks and/or related equipment,
such as pipes connecting the tanks, had migrated to the groundwater.
DOE has acknowledged that there are significant uncertainties and
data gaps in the understanding of the inventory, distribution, and
movement of contaminants in the vadose zone. This information is
essential, DOE has added, in evaluating the effects of releases of
radioactive or hazardous wastes to the environment.
Other recent findings about tank leaks and migration of wastes in the
vadose zone include:
-- DOE announced in February 1996 and September 1997, respectively,
that its Grand Junction team had found cesium 125 feet below one
single-shell tank farm and just above the water table under
another tank farm. After deepening the well near the first tank
farm, DOE found cesium at a depth of 142 feet and technetium at
177 feet, according to the lead scientist on the project.
-- An October 1996 draft report prepared for DOE by its Los Alamos
National Laboratory analyzed the history of leaks at one tank
farm and concluded that the leaks from four tanks may have been
3 to 6 times greater than previously reported.
-- In January 1998, DOE released a draft groundwater quality
assessment report by its Pacific Northwest National Laboratory
for a group of three single-shell tank farms, stating that
wastes from one farm has reached the groundwater.
--------------------
\8 Radioactive wastes contain three types of radiation. One of these
types--gamma--is, like radio waves, electromagnetic radiation. The
equipment used by the Grand Junction team detects radioactive
isotopes, such as cesium, that emit gamma radiation. The equipment
does not detect other types of radiation.
REVIEWERS CRITICIZED DOE'S
UNDERSTANDING OF VADOSE ZONE
CONDITIONS
---------------------------------------------------------- Letter :3.4
Several times from 1994 through 1997, outside reviewers, such as the
National Research Council, questioned DOE's understanding of
contamination conditions in the vadose zone and the potential effects
of the contamination on the groundwater. In March 1996, for example,
DOE asked the Council to review its draft environmental impact
statement for the TWRS program. In a September 1996 report, the
Council concluded the following:
-- An important component of a long-term commitment to remediating
the single-shell tanks is an adequate understanding of the
extent to which the soil and groundwater beneath the tanks have
been contaminated. Characterization (scientific investigation)
should continue until such an understanding has been obtained.
-- It is not evident how a tank waste retrieval and treatment
method can be rationally selected without also considering what
is to be done with the contamination left behind.
-- Adequate characterization of the tank wastes and surrounding
contaminated environment (in the vadose zone) will be required
for processing of wastes that are removed for treatment and for
the disposition of wastes not removed from the tanks either by
choice or necessity. To assess risks associated with wastes
removal, processing, and in-place disposition, DOE needs a
better understanding of what wastes have already leaked and how
rapidly the wastes are moving. Leakage from the tanks caused by
sluicing, as well as the risk associated with waste left in the
tanks, must be analyzed in the context of overall risks posed by
the Hanford Site. Finally, DOE needs to be concerned about
wastes at other nearby waste sites.
In response, DOE acknowledged that there was a high degree of
uncertainty about the level of contaminants in the vadose zone and
revised the final environmental impact statement accordingly.
The Council's conclusions about obtaining a better understanding of
the vadose zone to help in analyzing risks were similar to earlier
findings of the Defense Nuclear Facilities Safety Board.\9 In 1994,
the Board found that DOE needed to estimate the overall risk posed by
each of its nuclear sites (such as the Hanford Site) and not just the
risks from each individual activity or facility at each site. In a
recommendation covering all of DOE's nuclear sites, the Board said
that DOE should quantify the cumulative risk of harm from all of its
facilities at each nuclear site. According to the Board's staff,
implementing this recommendation at Hanford would require an
understanding of conditions in the vadose zone.
The most detailed outside review, in terms of the amount of feedback
provided to DOE, was conducted by a panel of four vadose zone experts
from 1996 and 1997. DOE convened the panel in 1996 to resolve the
issue of whether the cesium that the Grand Junction team had found
125 feet below one tank farm indicated migration through the vadose
zone or movement of the material down the borehole. The panel
concluded that it is likely that large quantities of cesium (and
other contaminants) are reaching the depths to which it has been
detected along narrow pathways in the formation. Similar to the
National Research Council, the panel concluded that
"Characterization of the vadose zone is an essential step toward
understanding contamination of the groundwater, assessing the
resulting health risks, and defining the concomitant groundwater
monitoring program necessary to verify the risk assessments."
The panel added that reliable computer models of groundwater
contamination cannot be developed without reliable data on the
transport of contaminants within the vadose zone. That subject,
according to the panel, is poorly understood and, as a result,
previous and ongoing computer modeling efforts are inadequate and
based on unrealistic and sometimes optimistic assumptions. The panel
characterized the output of such models as "entirely unreliable."
The panel made about 20 recommendations to DOE, including a
recommendation that the Department comprehensively study the vadose
zone. DOE generally agreed with the panel's conclusions and is
implementing many of the recommendations. The lack of funds is one
reason DOE gives for not implementing the remaining recommendations.
DOE's most recent response to this growing body of research and
evaluation came in a January 1998 report to the Secretary of Energy
by an internal management team. The team's report, which dealt with
management of the TWRS (tank farm) program, found that many key
questions remained unresolved about contamination in the vadose zone.
The team concluded that the program lacked credibility in part
because the program had not timely acknowledged the information it
possessed about the extent of contamination in the vadose zone. The
team concluded that
"Without significant and diligent management attention, these
credibility issues and the lack of adequate characterization of
vadose zone contamination could affect implementation of future
regulatory milestones for waste retrieval and tank closure."
--------------------
\9 The Board was created by the Congress to make recommendations to
the Secretary of Energy, related to DOE's nuclear operations and
wastes, to ensure the protection of public health and safety.
DOE RECOGNIZES THAT IT NEEDS A
STRATEGY FOR INVESTIGATING THE
VADOSE ZONE
------------------------------------------------------------ Letter :4
Because DOE believed that most wastes from leaking tanks would not
migrate to the groundwater, it did not see the need for a
comprehensive program for investigating the vadose zone. Therefore,
studies of the vadose zone were assigned relatively low priority for
funding, and the limited funds used for vadose zone activities were
not always spent efficiently. The division of responsibilities for
assessing conditions in the vadose zone among three organizational
units also contributed to the low priority assigned to this subject
because each unit typically viewed the subject only from the narrow
perspective of its own cleanup operations. With the emerging
evidence of waste migration to the groundwater, however, DOE now
recognizes that it needs a better understanding of vadose zone
conditions and, therefore, has begun to develop a strategy for
investigating the vadose zone.
DOE HAS NOT HAD A
COMPREHENSIVE PROGRAM FOR
INVESTIGATING THE VADOSE
ZONE
---------------------------------------------------------- Letter :4.1
DOE has based past efforts on what, given the many competing demands
for funds, it believed it could afford rather than on a clear sense
of what was needed to understand vadose zone issues. For example, in
our 1989 report, we recommended that the Department investigate
leakage of wastes from tanks into the vadose zone. Although DOE
agreed with our recommendation, its subsequent drilling of one new
borehole used up all of the money the Department was willing to spend
on this investigation. In this borehole, located near the tank with
the largest confirmed leak volume, DOE found mobile contaminants 121
feet below ground level. Scientists working on this project
recommended that DOE conduct additional studies, but the Department,
citing a lack of funds, declined.
This same pattern has continued as concerns about the vadose zone
mounted. For example, the Grand Junction team investigating old
boreholes proposed improvements costing about $600,000 that would
better define the contamination, enhance measurement in highly
contaminated areas, and allow moisture and temperature monitoring.
Several of these improvements had been recommended by DOE's expert
panel on the vadose zone. DOE has implemented one proposal costing
about $100,000; however, citing budgetary concerns, the Department
has not yet implemented the other recommendations.
Because DOE has never developed a comprehensive plan for
investigating the vadose zone, it also has not determined the funding
level required to obtain the understanding of vadose zone conditions
needed for future cleanup decisions and activities. Nevertheless,
some managers involved with the limited ongoing vadose zone
activities believe that they have already identified more essential
investigations than can be completed with the current level of
funding. Yet, in recent years DOE reduced funding levels for vadose
zone work in favor of what it decided was higher-priority work. For
the TWRS vadose zone program, for example, the funding level of $5.5
million in fiscal year 1994 declined to about $3.3 million in fiscal
year 1997.\10 For fiscal year 1998, DOE has budgeted $4 million and
has requested $4 million in 1999 for the TWRS vadose zone program.
The manager for the TWRS vadose zone program developed two
alternative plans for fiscal year 1998. According to this manager,
either of the two alternative plans, which he estimated would cost $8
million and $12 million, respectively, would have enabled the program
to make significant progress in implementing the recommendations of
the expert panel on the vadose zone. However, even these more
ambitious plans were less than what one member of the expert panel
suggested that DOE needs for an adequate understanding of conditions
in the vadose zone. In that member's view, the Department needs to
drill one well a year in each of the tank farms for several years--at
a cost he estimated at about $18 million a year.
With the limited amount of funds available for vadose zone work, it
is important for DOE to spend these dollars as effectively as
possible. Our review of recent TWRS vadose zone expenditures showed
this has not necessarily occurred. We reviewed two major drilling
projects in which work was marked by false starts, frequent
interruptions, and poor coordination. These projects are described
in appendix III.
DOE's Richland Office also spends a large portion of vadose zone
expenditures for functions other than field work. While drilling
boreholes and supporting Grand Junction's baseline characterization
effort are the two largest expenditures of the office's $4 million
budget for vadose zone activities in fiscal years 1998, DOE is
devoting about 25 percent of the budget to oversight, management, and
other administrative activities. (This amount is separate from, and
in addition to, normal administrative costs that are factored into
all field projects.) As a result, the amount of characterization work
that can be done is limited.
DOE's approach of dividing vadose zone responsibilities across
operating units has been a contributing factor to the low priority
the vadose zone has received. Under this approach, three different
organizational units have been responsible for understanding those
aspects of the vadose zone that related to their programs--TWRS for
the tank farms, Environmental Restoration for closed waste disposal
sites and other facilities, and Waste Management for stored and newly
generated wastes. One way in which this divided responsibility
contributed to lowering the priority for vadose zone issues can be
seen from DOE's initial attempt to develop a comprehensive plan for
investigating the vadose zone. In a 1992 report, we recommended that
DOE develop such a plan.\11 DOE concurred and began planning efforts.
However, in October 1994 DOE reassigned vadose zone responsibilities
from one group to the three programs and never issued the plan.
DOE's three primary organizational units at Hanford have also
typically viewed the issue of vadose zone contamination from the
narrow perspectives of their respective cleanup responsibilities.
For example, the recent studies of the migration of wastes through
the vadose zone have focused on wastes that have leaked from the tank
farms. The tank farms, however, are just one source of groundwater
contamination. In fact, when measured by volume, DOE has pumped the
largest quantity of liquid wastes directly into the ground. Yet, for
a number of years the Department has not conducted any systematic
monitoring of the migration of wastes from other waste sites.
DOE has drilled thousands of wells, conducted numerous other
investigations of soil conditions and contamination, and has compiled
historic information on the Hanford vadose zone, including the 200
area, in what it calls aggregate area management system reports.
However, the Department has never synthesized this information to
determine what useful information it has already collected and what
gaps exist in this information. As a result, DOE does not know what
additional information is needed, and at what cost, to enable the
Department to achieve its cleanup objectives and milestones. For
example, in the Tri-Party Agreement, DOE has committed to close its
single-shell tanks and hundreds of other waste sites outside the tank
farms by 2024. A sufficient understanding of conditions in the
vadose zone beneath and around these waste sites is necessary to
ensure that this milestone can be met. Such an understanding, for
example, could help DOE determine whether expensive covers need to be
placed over the various waste sites or if lesser measures are
sufficient. According to experts among DOE's contractors, developing
adequate information on waste migration may require several years of
monitoring data.
--------------------
\10 In fiscal year 1997, some amounts were spent on vadose zone
activities other than those for this specific program, but DOE budget
documents did not clearly identify the amounts.
\11 Nuclear Waste: Improvements Needed in Monitoring Contaminants in
Hanford Soils (GAO/RCED-92-149, July 6, 1992).
KEY CONSIDERATIONS IN
DEVELOPING A WORKABLE
STRATEGY
---------------------------------------------------------- Letter :4.2
DOE has begun to develop a strategy for investigating vadose zone
conditions. As of February 1998, DOE had taken steps to provide
greater attention from management, develop an investigation plan,
seek the views of outside experts and stakeholders, and improve
internal coordination. (Table 1 summarizes these actions as
described by DOE.) These steps appear to be in the right direction.
Whether the steps will ultimately be successful depends, in our view,
on how well DOE addresses the issues of (1) the relative funding
priority of vadose zone studies among competing demands for funding
site cleanup activities, (2) leadership and accountability for
developing and implementing the vadose zone plan, and (3) building
technical credibility into the vadose zone plan.
Table 1
Summary of Recent Vadose Zone Actions
Announced by DOE
Action Status as of February 1998
---------------------------------------- ----------------------------
Development of an overall plan Bechtel Hanford, the
Environmental Restoration
program's main contractor,
has been directed to take
the lead in developing a
plan. The framework for the
plan is to be completed in
February 1998.
Greater management attention DOE's vadose zone and
groundwater management
strategies are being
reviewed by the Office of
the Under Secretary of
Energy to assess issues
surrounding groundwater
contamination and the vadose
zone.
Improved coordination among responsible Environmental Restoration,
organizations TWRS, and Waste Management
have signed a memorandum
clarifying how the three
organizations will
coordinate vadose zone
responsibilities.
Environmental Restoration
has been directed to lead
the Hanford-wide integration
effort.
Review by outside experts DOE is reviving its use of
the independent panel of
vadose zone experts.
Stakeholder involvement A Hanford-wide team of
stakeholders for vadose zone
issues has been identified
but has not met. TWRS
program management
established its own team of
stakeholders to coordinate
and plan vadose zone
activities. The team is made
up of representatives of
site contractors, Washington
State, the state of Oregon,
regulators, and affected
Indian tribes. This team has
held several meetings.
Geophysical characterization\a DOE will continue the
characterization projects of
the team from its Grand
Junction Office until the
projects have been completed
(expected in Apr. 1999).
Drilling DOE plans to drill another
borehole to sample the soil
in the vadose zone.
Additional wells may be
needed in the future.
----------------------------------------------------------------------
\a Lowering radiation-measuring instruments into wells permits the
identification of gamma-emitting radioactive elements and the
measurement of their concentrations.
Although DOE now recognizes that it needs a better understanding of
vadose zone conditions, it has not yet determined if it will make
more funds available for vadose zone studies and, if so, where the
funds will come from. As discussed earlier, the vadose zone is an
important component of a complex environmental system. Overall clean
up at Hanford will require DOE to make a number of key technical
decisions related to emptying and permanently closing the tank farms;
remediating the many cribs, ponds, trenches, and other waste sites;
and assessing the effects of these decisions on the vadose zone.
Making these decisions will require DOE to demonstrate that the
residual contamination of the vadose zone from all sources on the
site does not present unacceptable risks. Only when the significance
of vadose zone studies to the overall cleanup of the site has been
made clear will DOE be in a good position to fund--or not fund--these
studies.
DOE has also begun to address the leadership of, and accountability
for, the new vadose zone strategy. First, the Secretary of Energy
has tasked the Under Secretary of Energy with reviewing Hanford's
programs for vadose zone and groundwater management. Also, in August
1997, the Environmental Restoration, TWRS, and Waste Management
programs agreed to coordinate their activities. Subsequent
refinements have led to the Environmental Restoration unit's taking
the overall lead in coordinating vadose zone efforts. In
conjunction, the integrating contractor for this program is
developing an approach to an overall plan. Although these steps are
promising, much hard work remains. In its January 1998 report to the
Secretary, the management review team captured the amount of
organizational shifting that will have to take place:
"Even with the reorganization, the task of coordination and
integration will be significant and require considerable
attention by [DOE-Richland] senior managers. The new MOA
[memorandum of agreement] still faces a myriad of implementation
and coordination issues because of the many organizations that
still have key responsibilities for issues that cross over both
the vadose zone and groundwater programs. Additionally, the
site is still operating under different program management plans
for [the Hanford tank waste initiatives], vadose zone, and
groundwater. The actual staff work is being done by two major
integrating contractors--Bechtel Hanford and Fluor Daniel--and
Lockheed Martin Hanford Company, a subcontractor to [Fluor
Daniel], where much of the actual vadose zone work is being
conducted. All of these factors suggest that a high degree of
coordination will ultimately be required if the site is to build
credibility with external parties."
There also are signs that DOE's efforts still do not reflect an
integrated approach among organizational units at the Hanford Site.
For example, DOE's management review team was critical of recently
released draft reports confirming that tank wastes were contributing
to the contamination of groundwater. The team noted that the reports
contain little discussion of or data from previous attempts to
characterize the vadose zone. The team concluded that "The clear
lack of substantive discussion of the links between available vadose
zone and groundwater data suggest the degree to which the two [vadose
zone and groundwater] programs have yet to be integrated."
Finally, to help ensure that the new strategy will be credible, DOE
intends to seek the participation of its panel of independent vadose
zone experts and Hanford stakeholders in developing and implementing
the strategy. A 1993 report by the Secretary of Energy Advisory
Board's Task Force on Radioactive Waste Management found a widespread
lack of public trust in DOE activities. The task force attributed
this problem to the public's experiences with the Department. This
problem also affects the vadose zone program today, as DOE's
management review team found that external credibility issues
continue with the program. Examples cited in the review team's
January 1998 report include tardiness by DOE in acknowledging the
extent of contamination of the vadose zone, unresponsiveness to
recommendations by independent experts, and difficulties in moving
towards a new organizational structure for managing vadose zone
issues.
One option potentially available to DOE in improving its credibility
is greater reliance on independent technical staff and review by
outside experts. The use of independent technical staff has already
been important in the recent progress DOE has made in understanding
the vadose zone under the tank farms. DOE used the team from its
Grand Junction Office to analyze the extent of potential
contamination and, when controversy developed over the team's
findings at one location, DOE brought in the expert panel to provide
further guidance. Using staff who have established credibility on
the issues and who are independent could greatly enhance
stakeholders' confidence.
DOE's responses to the efforts of independent technical staff and
outside technical experts, however, have not always been effective.
Three examples illustrate this point. First, the original Grand
Junction baseline characterization project was scheduled to last 3
years, be completed in 1997, and cost about $8.6 million. However,
DOE has not funded several proposed program improvements in the last
3 years and diverted some of its resources to support other efforts,
such as the new boreholes. As a result, completion of the original
project will now cost about $10 million and require almost 5 years,
ending in 1999.
Second, DOE committed to further use of the expert panel on the
vadose zone but did not use the panel again for almost a year after
the panel had issued its report. Although DOE has developed a
schedule for implementing the panel's recommendations, some efforts
have been delayed due to a lack of funds. According to DOE's manager
for the TWRS vadose zone program, DOE disagrees with some of the
panel's recommendations, such as the need for having an independent
group perform computer modeling of how waste contaminants may be
transported through the vadose zone.
Third, DOE has been slow to address recommendations by independent
technical experts for improving ongoing projects such as the computer
modeling that DOE uses to simulate the movement of waste contaminants
through the vadose zone. As discussed earlier, reviews by the
National Research Council and the panel of vadose zone experts in
1996 and 1997 had both been critical of the modeling methods DOE was
using. Subsequently, DOE's management review team reported in
January 1998 that DOE's Richland Office did not appear to be actively
addressing the experts' recommended changes to the models. The team
concluded that "Prompt implementation of the experts'
recommendations, or explanations why recommendations are not being
pursued, would greatly enhance the program's credibility."
DOE has other nuclear waste management programs that it could draw on
to help enhance, through systematic external review, the credibility
of future efforts to characterize the Hanford Site vadose zone. At
Hanford, for example, the Department could adapt procedures for
obtaining external reviews that it follows in its projects to
investigate Yucca Mountain, Nevada, and the Waste Isolation Pilot
Plant near Carlsbad, New Mexico, as potential sites for the permanent
disposal of certain nuclear wastes. On both of these projects,
organizational and procedural requirements for periodic independent
reviews have contributed to better science and, therefore, increased
the credibility of scientific methods and results. In this regard,
the TWRS management team cited the need for greater ongoing use of
expert panels and for greater diligence in responding to and
implementing expert panels' recommendations.
CONCLUSIONS
------------------------------------------------------------ Letter :5
DOE's past efforts have left the agency unable to answer basic
questions about what radioactive and hazardous wastes are in the
vadose zone at the Hanford Site, how quickly these wastes are
migrating, the degree to which they might contaminate the underlying
groundwater, and the risks of such contamination to current and
future residents of the surrounding area. Answering these questions
is critical to proceeding with the overall cleanup of the Hanford
Site because the answers will affect the selection of cleanup
strategies and DOE's ability to comply with agreed-upon cleanup
schedules.
DOE's proposal to inject water under pressure into waste storage
tanks to dissolve hardened wastes illustrates the weakness in the
Department's current understanding of conditions in the vadose zone.
DOE acknowledges that this approach could allow additional wastes to
leak into the vadose zone from tanks that have already leaked.
Independent experts, however, have pointed out that the risks from
additional leakage must be analyzed to determine if they are
acceptable.
Although DOE's management recently made a strong commitment to
dealing with vadose zone issues, past actions have not been
encouraging. Ways to help ensure that the new strategy is successful
include (1) identifying the information needed for future cleanup
decisions and specifying how this information is to be obtained on
time, (2) addressing leadership and accountability issues; and (3)
adopting methods for ensuring that DOE's approach to the vadose
zone--and the information that is collected--forms a technically
credible basis for making cleanup decisions.
RECOMMENDATIONS
------------------------------------------------------------ Letter :6
We recommend that the Secretary of Energy develop a comprehensive
vadose zone strategy for the Hanford Site that addresses cleaning up
the high-level waste tank farms and the cribs, ponds, trenches, and
other waste sites. The strategy should do the following:
-- Address the importance of understanding conditions in the vadose
zone to ongoing cleanup activities and future decisions on
cleaning up the Hanford Site. Examples of such activities and
future decisions include, but are not limited to, (1) covering
tank farms with gravel; (2) slowing the removal of wastes from
single-shell tanks; and (3) deciding whether to retrieve wastes
from leaking single-shell tanks and if so, how.
-- Define leadership roles within DOE and its contractors. The
overall leadership for this program should be clearly defined,
with measurable performance goals and accountability for meeting
the goals established at the outset.
-- Identify steps to ensure the credibility of the process and the
information that is collected, such as review by stakeholders
and subject matter experts.
We also recommend that the Secretary of Energy reevaluate, as soon as
better information is available on the behavior of wastes in the
vadose zone, the Department's proposed strategy of removing
additional wastes from single-shell tanks by injecting pressurized
water into the tanks.
AGENCY COMMENTS AND OUR
EVALUATION
------------------------------------------------------------ Letter :7
We provided a draft of this report to DOE for its review and comment.
The Department's comments appear in appendix I.
DOE agrees with our recommendations and our assessment that
significant uncertainties and data gaps exist in its understanding of
the inventory, distribution, and movement of contaminants in the
vadose zone at the Hanford Site. DOE said that addressing these
uncertainties and data gaps is essential in evaluating the effects of
radioactive or hazardous wastes on the environment. DOE also said
that it will develop, by October 1998, a Hanford-wide plan for
assessing waste contaminants in the vadose zone and groundwater that
-- establishes a project office, staffed by representatives of the
affected organizations, that will be responsible for developing
a comprehensive vadose zone investigation program;
-- includes scientific research and development of technology as
major components of the plan so that DOE can develop and use
optimal technologies for remediation of the vadose zone;
-- identifies steps to contain contaminants; and
-- provides for independent technical review and meaningful
involvement by stakeholders.
From this description of DOE's proposed plan, it appears that DOE is
responding to our recommendations.
DOE also said that it is taking steps to reduce the risk of
contaminants' entering the vadose zone. These steps include
requesting from the Congress a supplemental appropriation and
approval to reprogram existing funds. If approved, the request would
provide $15 million for accelerated removal of pumpable liquids from
waste storage tanks that are suspected of leaking. Finally, DOE
provided technical comments (1) updating the status of its ongoing
vadose zone, waste retrieval, and technology development activities
and (2) clarifying what it viewed as omissions or factually imprecise
statements in our draft report. We have incorporated these technical
comments, as appropriate, in our report.
---------------------------------------------------------- Letter :7.1
We directed much of our review on wastes that have leaked from
storage tanks and, to a lesser extent, on the effects that other
programs and activities at the site have had on the vadose zone. To
assess the adequacy of DOE's current understanding of the extent to
which waste materials are moving through the vadose zone, we
interviewed DOE officials at Hanford, Grand Junction, Colorado, and
Washington, D.C. We also obtained and reviewed reports from these
officials and officials of other DOE contractors at Hanford. We
reviewed environmental impact statements and related documents;
observed meetings of the Hanford Advisory Board; and discussed vadose
zone issues with representatives of stakeholder groups, state and
federal regulators, and outside experts, such as expert panel members
and staff of the National Academy of Sciences.
To evaluate DOE's current strategy for investigating vadose zone
conditions, we interviewed officials of DOE and its contractors who
are responsible for the vadose zone and groundwater programs;
observed various initiatives, such as meetings of the TWRS Vadose
Zone Team; and reviewed information on DOE's program to extend the
borehole in one tank farm. We also reviewed the report of DOE's TWRS
management review team and interviewed the team's director. We
performed our work from May 1997 through February 1998 in accordance
with generally accepted government auditing standards.
---------------------------------------------------------- Letter :7.2
As arranged with your offices, unless you publicly announce its
contents earlier, we plan no further distribution of this report
until 30 days after the date of this letter. At that time, we will
send copies to the Secretary of Energy and other interested parties.
We will also make copies available to others upon request.
Please call me at (202) 512-3991 if you or your staff have any
questions. The major contributors to this report are listed in
appendix IV.
Gary L. Jones
Associate Director, Energy,
Resources, and Science Issues
(See figure in printed edition.)Appendix I
COMMENTS FROM THE DEPARTMENT OF
ENERGY
============================================================== Letter
(See figure in printed edition.)
(See figure in printed edition.)
(See figure in printed edition.)
(See figure in printed edition.)
(See figure in printed edition.)
(See figure in printed edition.)
(See figure in printed edition.)
(See figure in printed edition.)
OTHER DOE ACTIONS THAT COULD
EXACERBATE VADOSE ZONE
CONTAMINATION AT THE HANFORD SITE
========================================================== Appendix II
One pending Department of Energy (DOE) project involves injecting
water into single-shell tanks to dissolve solid wastes into a slurry
for retrieval. This step would cause additional leaks from some
tanks and, therefore, could increase the potential for wastes to
migrate through the vadose zone to the groundwater. Two actions that
DOE is currently taking, presented in this appendix, also could
increase the amount of waste contaminating the vadose zone.
COVERING TANK FARMS WITH GRAVEL
-------------------------------------------------------- Appendix II:1
DOE is proceeding with a program that calls for using uncontaminated
gravel to replace or add to the existing gravel surface of tank
farms. Gravel above the tanks allows rain and snow to drive leaked
or spilled wastes through the vadose zone toward the water table. A
1989 modeling study by DOE's experts estimated that about
three-fourths of annual precipitation migrates through this coarse
backfill and increases the rate of movement of some contaminants and
recommended a different type of cover.\1
DOE selected its approach of adding more gravel because the clean
gravel helps shield workers from exposure to radiation. DOE also
evaluated other approaches for reducing risks to workers while
minimizing infiltration that did not involve putting gravel over the
tanks, but it selected the gravel approach because it was relatively
inexpensive. DOE has completed this effort in three tank farms at a
cost of about $1 million, but no funding is currently available to
continue.
--------------------
\1 According to the one of the authors of the study, contractor
scientists and others recommended several times that DOE measure the
infiltration of precipitation in the tank farms but DOE never funded
the studies.
SLOWING THE PUMPING OF WASTES
FROM SINGLE-SHELL TANKS
-------------------------------------------------------- Appendix II:2
DOE has slowed its efforts to pump liquid wastes from single-shelled
tanks into double-shell tanks, leaving the wastes susceptible to
additional leakage. In 1980, DOE began a program to remove all
pumpable liquid from single-shell tanks by 1996 or earlier. At the
time, the single-shell tanks contained an estimated 8.5 million
gallons of pumpable liquid. The pumping program has encountered
numerous delays. As of November 1997, about 5.7 million gallons of
pumpable liquid remains in 30 tanks. Current milestones call for
pumping to be completed by 2000, but DOE has requested a 3-year
extension.
Additional leakage has resulted from not completing the pumping on
the originally scheduled date. DOE estimates that one unpumped tank
leaked an estimated 7,500 gallons of high-level mixed waste to the
vadose zone before it could be pumped. Currently, three tanks
assumed to have leaked in the past have not yet been pumped. These
tanks hold an estimated 574,000 gallons of pumpable liquid waste.
The Director of Washington State's Department of Ecology, in
rejecting DOE's request to delay one of the program milestones, said
that the wastes present a very real and increased threat to health
and the environment.
Delays in pumping the tanks have been caused by budget fluctuations,
technical issues, and safety issues. DOE, citing overall budget
constraints, had cut its proposed spending in fiscal year 1998 to
about one-half the 1997 level of about $9 million. According to the
manager of the TWRS project, DOE plans, during fiscal year 1998, to
start pumping three of the four tanks that had leaked and to try to
reduce program costs. DOE recently submitted a request to Congress
for $15 million in funds for accelerated removal of pumpable liquids.
EXAMPLES OF INEFFICIENT USE OF
VADOSE ZONE INVESTIGATION FUNDS
========================================================= Appendix III
With the limited amount of funds available for vadose zone work, it
is important for DOE to spend these dollars as effectively as
possible. Our review of recent expenditures on investigations of
vadose zone conditions around tank farms showed this has not
necessarily occurred. We identified a number of cases in which work
on individual drilling projects was marked by false starts, frequent
interruptions, and poor coordination.
WELL DRILLING ACTIVITIES
------------------------------------------------------- Appendix III:1
At Hanford, one of the key steps in gathering extensive information
about vadose zone conditions is to drill wells and sample the soil to
learn about soil conditions and the distribution of radioactive and
hazardous materials. Drilling wells is one of the major expenditures
of the vadose zone programs, and DOE expects that a number of
additional wells will be needed. We reported in early 1993 that high
well drilling costs could be reduced\1 and, on the basis of our
current review of the recent drilling of two tank farm wells, our
conclusion has not changed.
The first well, drilled about 180 feet deep in 1993, was located near
the largest confirmed tank leak (tank T-106) at the Hanford Site.
Several officials involved with the drilling of this well cited
problems with poor management of the borehole project. Staff
assigned to the project said that it was poorly organized and far
more costly than it should have been. Instead of beginning the
project in the spring, DOE began drilling in November and encountered
severe winter weather, which hindered or prevented drilling on 6
days. Overall weather, staffing, equipment, site, lunch breaks, and
other problems resulted in only two-thirds of the time during the 82
working days being spent in drilling and sampling or on related
activities. In total, the borehole cost at least $3.2 million for
activities such as installation, laboratory analyses, and report
preparation.\2 The borehole, planned to take 2-1/2 months, instead
required 5 months.
The second well that we looked at was a project, recommended by DOE's
expert panel on the vadose zone, to deepen to groundwater (about 210
feet) the earlier well that had found the cesium at 130 feet beneath
the surface. According to DOE's drilling expert, this project had
challenges to overcome from the beginning. The first 130 feet
consisted of a 6-inch steel pipe with a pointed tip that had been
driven into the ground. Because the tip was welded on instead of
removable, the DOE crew spent 14 days trying to remove it. The crew
had to add water to the hole during the removal, which altered the
consistency of the first samples taken. DOE's drilling expert had
told staff of the vadose zone program to think about the eventual
uses of the borehole before initiating the original drilling. The
drilling expert believed that DOE should have considered the
possibility that they would be deepening the hole, which would have
lead DOE to design the original hole differently using a larger pipe
and a removable tip. However, DOE did not plan for this possibility.
Instead of just deepening the existing well, the DOE drilling experts
recommended that DOE first investigate the most effective ways to
drill in the tank farm environment so that cost-effective drilling
can be done for the many wells that they believe will be needed to
fully characterize the vadose zone.\3 DOE's TWRS vadose zone program
manager said they went ahead because DOE believed that the data would
provide needed information about conditions in the lower vadose zone.
Using a method that drills only a few feet a day in Hanford
conditions, the drilling and sampling, scheduled to take 24 days
instead took 62 days and the entire project cost over $600,000
(including analysis of samples). Aside from the slow drilling
method, other problems included limited advanced planning which
caused DOE to stop work and revise the work package two times. In
addition, failure of DOE's tank farms contractor to manage the work
so that adequate support was available led to missing 16 days of work
and starting late on many days. Despite overtime, the drilling crew
averaged only about 5 hours work a day. The poor support by the tank
farms contractor caused one of the Indian tribes in December 1997 to
call for immediate transfer of vadose zone responsibilities to the
Environmental Restoration program.
--------------------
\1 Nuclear Waste: Hanford's Well-Drilling Costs Can Be Reduced
(GAO/RCED-93-71, Mar. 1993).
\2 DOE's financial records were incomplete. A DOE contractor manager
on the project told us that another $882,000 was spent on project
planning and documentation.
\3 The experts noted that DOE did not design the original hole to
allow for readily extending the well.
MONITORING EQUIPMENT
------------------------------------------------------- Appendix III:2
In the 1990 study by the Secretary of Energy's "Tiger Team" review of
the Hanford Site and in our 1992 report, a number of recommendations
for technical improvements in the vadose zone monitoring techniques
were recommended. While DOE concurred with the findings, the
engineer responsible for the program said no changes were made to the
equipment or procedures because the equipment was old and had little
ability to be adjusted. This equipment is still used at some tanks
even though much more capable equipment is on site.
MODELING STUDIES OF VADOSE ZONE
AND GROUNDWATER
------------------------------------------------------- Appendix III:3
Work continues on numerous modeling studies. In addition, to the
money being spent directly on vadose zone characterization
activities, DOE is spending about $1.5 million on several different
groundwater and vadose zone modeling projects to support other
programs during fiscal years 1996 to 1998. DOE's expert panel
concluded that reliable modeling could not be done without reliable
data on contaminant transport. In addition to developing more data,
the panel recommended that DOE's modelers assess the various models
to determine which best fits the Hanford site. The panel also
suggested that DOE's modeling efforts should be reviewed by others.
The management review team cited this as an area where TWRS is not
actively addressing the recommendations. According to the manager of
DOE's groundwater program, the Under Secretary of Energy has also
called for the modeling to be reviewed by outside experts.
MAJOR CONTRIBUTORS TO THIS REPORT
========================================================== Appendix IV
RESOURCES, COMMUNITY, AND ECONOMIC
DEVELOPMENT DIVISION, WASHINGTON,
D.C.
Dwayne E. Weigel, Assistant Director
Susan W. Irwin, Senior Attorney
SEATTLE, WASHINGTON
Christopher R. Abraham, Evaluator-in-charge
John E. Cass, Member
Stanley G. Stenersen, Report Analyst
RELATED GAO PRODUCTS
Nuclear Waste: Further Improvements Needed in the Hanford Tank Farm
Maintenance Program (GAO/RCED-95-29, Nov. 8, 1994).
Nuclear Waste: Hanford Tank Waste Program Needs Cost, Schedule, and
Management Changes (GAO/RCED-93-99, Mar. 8, 1993).
Nuclear Waste: Improvements Needed in Monitoring Contaminants in
Hanford Soils (GAO/RCED-92-149, July 6, 1992).
Nuclear Waste: Problems and Delays With Characterizing Hanford's
Single-Shell Tank Waste (GAO/RCED-91-118, Apr. 23, 1991).
Nuclear Waste: DOE's Management of Single-Shell Tanks at Hanford,
Washington (GAO/RCED-89-157, July 18, 1989).
*** End of document. ***