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United States Government Accountability Office: 
GAO: 

Report to the Honorable Ron Wyden, U.S. Senate: 

November 2014: 

Hanford Cleanup: 

Condition of Tanks May Further Limit DOE's Ability to Respond to Leaks 
and Intrusions: 

GAO-15-40: 

GAO Highlights: 

Highlights of GAO-15-40, a report to the Honorable Ron Wyden, U.S. 
Senate. 

Why GAO Did This Study: 

DOE recently reported that nuclear waste is leaking from two of its
underground storage tanks (T-111 and AY-102) at Hanford and that water 
was intruding into AY-102 and other tanks. Also, DOE has been 
experiencing delays in the construction of the WTP, a collection of 
facilities that are to treat the tank waste for disposal. These 
recently reported leaks and intrusions, combined with construction 
delays, have raised questions among regulators, the public, and Congress
about the risks posed by continuing to store waste in the aging tanks. 

GAO was asked to report on the tank waste cleanup program. This report
examines: (1) the condition of the tanks, (2) actions DOE has taken or
planned to respond to the recent tank leaks and water intrusions, and 
(3) the extent to which DOE’s tank management plans consider the
condition of the tanks and the delays in completing construction of 
the WTP. GAO obtained and reviewed relevant reports concerning the 
leaks, the status of the tanks, and the volumes of waste and available 
space in the tanks. GAO toured the site and interviewed DOE officials 
and responsible contractors. 

What GAO Found: 

From 2012 to 2014, the Department of Energy (DOE) assessed the physical
condition of the 177 storage tanks at its Hanford, Washington, site in 
which it stores about 56 million gallons of nuclear waste and found 
them to be in worse condition than it assumed in 2011 when developing 
its schedule for emptying the tanks. For the 149 single-shell tanks 
(SST), DOE previously pumped nearly all of the liquid waste out of the 
SSTs into the 28 newer double-shell tanks (DST) to reduce the 
likelihood of leaks. However, after detecting water intruding into
several SSTs, DOE reexamined them all and found that water was 
intruding into at least 14 SSTs and that 1 of them (T-111) had been 
actively leaking into the ground since about 2010 at a rate of about 
640 gallons annually. Regarding the DSTs, in 2012, DOE discovered a 
leak from the primary shell in tank AY-102. 

DOE determined that the leak was likely caused by construction flaws and
corrosion in the bottom of the tank. DOE found that 12 DSTs have similar
construction flaws but has not determined the extent to which the 
other 27 DSTs are subject to the same corrosion that likely 
contributed to the leak in AY-102. In response to the waste leaks and 
water intrusion, DOE has taken or planned several actions. For SSTs, 
DOE conducted additional tank inspections and temporarily increased 
the frequency of monitoring the tank waste levels from annually or 
quarterly to monthly. In addition, after finding flaws in its methods to
monitor for leaks and intrusions, DOE modified its methods, which it 
believes may lead to more effective monitoring. For DSTs, DOE 
increased the frequency (from every 5 to 7 years to every 3 years) and 
scope of its tank inspections and convened a panel of experts to 
evaluate existing tank monitoring and inspection procedures. DOE also 
plans an independent assessment of the integrity of the DSTs 
(scheduled to be completed no later than 2016). 

DOE’s current schedule for managing the tank waste does not consider the
worsening conditions of the tanks or the delays in the construction of 
the Waste Treatment and Immobilization Plant (WTP), a facility being 
constructed to treat the waste and prepare it for final, long-term 
disposal. First, the leak in AY-102 combined with planned waste 
transfers from SSTs has reduced the available DST tank storage 
capacity. Future leaks and intrusions, which become more likely as the 
tanks’ condition worsens, would place additional demands on the 
already limited DST storage space, and it is unclear how DOE would 
respond. According to DOE, recent efforts to evaporate some of the 
water from the waste have already freed up 750,000 gallons of DST 
space. Second, in March 2014, DOE announced further delays in the 
construction of the WTP and that these delays will affect the schedule 
for removing waste from the tanks. However, DOE has not estimated the 
impact of the WTP delays on its schedule to remove the waste from the 
tanks. As a result, DOE cannot estimate how long the waste will remain 
in the aging tanks. Also, DOE officials and members of a 2014 expert
panel convened to examine the integrity of the DSTs have said that 
corrosion is a threat to DST integrity, and, according to the panel, 
that there are deficiencies in DOE’s understanding of corrosion in all 
of the DSTs. DOE lacks information about the extent to which the other 
27 DSTs may also be susceptible to corrosion similar to AY-102. 
Without determining the extent to which the factors that contributed 
to the leak in AY-102 were similar to the other 27 DSTs, DOE cannot
be sure how long its DSTs can safely store waste. 

What GAO Recommends: 

GAO recommends that DOE assess the extent to which other DSTs have
corrosion factors similar to AY-102, update its schedule for removing 
waste from the tanks, and assess the alternatives for creating 
additional DST space. DOE agreed with this report and its 
recommendations. 

View [hyperlink, http://www.gao.gov/products/GAO-15-40]. For more 
information, contact David C. Trimble at (202) 512-3841 or 
trimbled@gao.gov. 

[End of section] 

Contents: 

Letter: 

Background: 

Condition of Tanks Is Worse than Assumed under DOE's Current Schedule 
for Retrieving Tank Waste: 

DOE Has Taken and Planned Several Actions to Respond to Recent Leaks 
and Intrusions, Including Modifying Its Tank Monitoring and Inspection 
Procedures: 

DOE's Current Waste Retrieval Schedule Does Not Account for the 
Worsening Condition of the Tanks or WTP Delays: 

Conclusions: 

Recommendations for Executive Action: 

Agency Comments and Our Evaluation: 

Appendix I: Timeline of Hanford Single-Shell Tanks: 

Appendix II: Timeline of Hanford Double-Shell Tanks: 

Appendix III: Age and Retrieval Schedule for Hanford Single-Shell 
Tanks: 

Appendix IV: Comments from the Department of Energy: 

Appendix V: GAO Contact and Staff Acknowledgments: 

Table: 

Table 1: Age and Retrieval Schedule for Single-Shell Tanks: 

Figures: 

Figure 1: Hanford Waste Storage Tanks: 

Figure 2: Composition of Waste in Hanford Tanks, as of May 2014: 

Figure 3: Resource Conservation and Recovery Act of 1976 Requirements 
for Underground Tanks: 

Figure 4: Approximate Configuration of Space Usage in Hanford's 177 
Tanks, as of May 2014: 

Figure 5: Current and Planned Usage of Empty Double-shell Tank Space 
at Hanford, as of May 2014: 

Figure 6: Timeline of Hanford Single-shell Tanks: 

Figure 7: Timeline of Hanford Double-shell Tanks: 

Abbreviations: 

CERCLA: Comprehensive Environmental Response, Compensation, and 
Liability Act: 

DOE: Department of Energy: 

DST: double-shell tank: 

EIS: environmental impact statement: 

RCRA: Resource Conservation and Recovery Act: 

SST: single-shell tank: 

TPA: Tri-Party Agreement: 

WTP: Waste Treatment and Immobilization Plant: 

[End of section] 

United States Government Accountability Office: 
GAO:
441 G St. N.W. 
Washington, DC 20548: 

November 25, 2014: 

The Honorable Ron Wyden: 
United States Senate: 

Dear Senator Wyden: 

The Department of Energy (DOE) is responsible for one of the world's 
largest environmental cleanup projects: the treatment and disposal of 
millions of gallons of radioactive and hazardous waste at its 586-
square mile Hanford site in southeastern Washington State. A total of 
nine nuclear reactors--including the world's first operating large-
scale reactor, developed as part of the Manhattan Project during World 
War II--were built at Hanford and operated until the late 1980s. The 
primary mission of these reactors was to produce plutonium and other 
special nuclear materials for DOE's nuclear weapons program. Some of 
the most dangerous hazardous and radioactive waste that resulted from 
nuclear materials production was stored in 177 large underground 
storage tanks. The underground tanks currently hold more than 56 
million gallons of this waste--enough to fill an area the size of a 
football field to a depth of over 150 feet. 

In October 2012, DOE announced that nuclear waste had leaked into the 
space between the inner and outer shell of one of its underground 
storage tanks (tank AY-102) at the Hanford site. The announcement--the 
first to identify that one of DOE's 28 double-shell tanks (DST) at the 
site had leaked--raised concerns among DOE, its regulators, the 
public, and Congress about the viability of the other DSTs at Hanford 
and the risks posed by continuing to store waste in those tanks. Four 
months later, in February 2013, following a review of the 149 single-
shell tanks (SST) at the Hanford site, DOE announced that waste was 
leaking into the environment from at least one SST (tank T-111). More 
recently, in its May 2014 update on the status of the tanks, DOE 
reported that it had detected water intruding into at least 14 SSTs. 

DOE spends over $1 billion each year--through its Office of River 
Protection in Richland, WA--on its tank waste retrieval and treatment 
program at Hanford. Nearly half of this amount is spent managing the 
underground waste storage tanks, including, among other activities, 
monitoring them for leaks and assessing their integrity. The remaining 
funding is spent on the design and construction of a Waste Treatment 
and Immobilization Plant (WTP), a collection of facilities that will 
treat the waste in the tanks for disposal, since the tanks were never 
intended to be a final storage solution for the waste.[Footnote 1] The 
WTP is a key element of DOE's tank waste cleanup plan which includes 
retrieving the waste from the tanks, treating it in the WTP, and 
disposing of the waste. As we have long found, most recently in a 
December 2012 report, as the cleanup effort has unfolded, multiple 
technical challenges in the design and construction of the WTP have 
caused delays and resulted in mounting costs.[Footnote 2] These delays 
could affect DOE's ability to manage the waste in the tanks. 

GAO was asked to examine (1) the condition of the tanks, (2) actions 
DOE has taken or planned to respond to the recent tank leaks and water 
intrusions, and (3) the extent to which DOE's tank management plans 
consider the condition of the tanks and the delays in completing 
construction of the WTP.[Footnote 3] 

To conduct our work, we reviewed relevant tank waste management 
requirements, including applicable federal and state laws and 
regulations, DOE tank waste management procedural documents, and 
agency reports; toured the Hanford site, including DOE's tank 
monitoring operations and control center; and interviewed DOE 
officials and their contractors, officials from the Washington State 
Department of Ecology (Ecology) responsible for overseeing tank waste 
issues, and officials from the Defense Nuclear Facility Safety Board 
(Safety Board)--an independent oversight agency created by Congress to 
assess safety conditions and operations at defense nuclear facilities 
at DOE's sites. To assess the current condition of the tanks, we 
obtained and reviewed relevant DOE reports concerning the recent leaks 
and reports assessing the previously known condition of the tanks and 
spoke with Ecology officials and DOE officials and their contractors 
responsible for managing the tanks. To determine the amount and type 
of waste in the tanks, we used DOE's monthly tank waste summary 
reports. We found that, while exact amounts and types of waste in the 
underground tanks are difficult to calculate, the data in DOE's 
monthly reports was sufficiently reliable for the purposes of this 
report. To determine the actions DOE has taken or planned to respond 
to the recent tank leaks, we reviewed recent reports by DOE and by an 
expert panel convened by DOE to review the status of the tanks, and 
interviewed Ecology officials and DOE officials and their contractors. 
Finally, to examine the extent to which DOE's tank management plans 
account for the current condition of the tanks and the delays in 
completing construction of the WTP, we reviewed information on the 
available space in the DSTs, the volumes of the waste stored in the 
SSTs and DSTs, the volumes of waste that DOE is planning on 
transferring from SSTs and DSTs to other DSTs, and the potential 
volumes of waste DOE may need to transfer from SSTs and DSTs in the 
future. We also reviewed DOE's and Ecology's March 2014 proposals to 
amend a 2010 consent decree between DOE and Ecology, and discussed 
these proposals with DOE and Ecology officials.[Footnote 4] We also 
reviewed DOE's 2011 Office of River Protection System Plan and 2012 
Environmental Impact Statement (EIS). 

We conducted this performance audit from June 2013 to November 2014, 
in accordance with generally accepted government auditing standards. 
Those standards require that we plan and perform the audit to obtain 
sufficient, appropriate evidence to provide a reasonable basis for our 
findings and conclusions based on our audit objectives. We believe 
that the evidence obtained provides a reasonable basis for our 
findings and conclusions based on our audit objectives. 

Background: 

From 1944 through 1988, the production of plutonium at Hanford 
generated about 525 million gallons of radioactive and hazardous 
waste. Some of the waste was dumped directly into the soil, some was 
encased in drums or other containers and buried, and some was stored 
on-site, underground in 149 SSTs and 28 DSTs. This section describes 
the history of the Hanford tanks, the contents of the tanks, and tank 
regulations and oversight. 

History of Hanford Tanks: 

The first underground storage tanks at Hanford were SSTs and were 
built from the 1940s through the mid-1960s. The SSTs consist of an 
outer concrete wall lined with one layer of carbon steel and were 
built with a design life of approximately 25 years. While a tank's 
design life is not a firm deadline beyond which a tank is no longer 
viable, site engineers at the time considered design life a reasonable 
estimate of how long a tank could be expected to effectively contain 
radioactive and hazardous waste. In the 1940s and 1950s, site 
contractors did not regard the tanks as a permanent solution to the 
waste produced at Hanford and viewed tank failures as inevitable. It 
was assumed that as the tanks failed, new tanks would be constructed 
to store the waste until a more permanent disposal solution could be 
developed.[Footnote 5] 

Beginning in the 1960s, DOE began reporting that some of the SSTs were 
leaking waste, and DOE estimates that as many as 61 SSTs may have 
leaked a total of over 1 million gallons of waste into the ground. 
After DOE discovered leaks in some of the SSTs, a new tank design 
using two carbon-steel shells (referred to as DSTs) was adopted. From 
1968 through 1986, DOE built 28 DSTs, each with a storage capacity of 
1 million gallons or more and each with a design life ranging from 20 
to 50 years. (See appendix I-III for design life data for each tank.) 
The primary design difference between Hanford's single-and double-
shell underground waste storage tanks--a second carbon-steel lining, 
or shell, within the outer concrete housing to provide secondary 
containment of the waste--improved DOE's ability to monitor and assess 
the tanks' integrity and contents. As shown in figure 1, the two 
shells in the DSTs are separated by about 3 feet of space, or annulus, 
which enables workers to use remote leak detection sensors and 
remotely operated cameras to see between the inner and outer shells, 
thereby making it possible to find signs of corrosion or leaks before 
waste breaches the outer shell and leaches outside the tank structure. 

Figure 1: Hanford Waste Storage Tanks: 

[Refer to PDF for image: illustration] 

Beneath ground level: 

Single-shell tank: 
Dome; 
Reinforced concrete; 
Carbon-steel shell; 
Risers; 
Solid waste; 
Liquid waste; 
Empty/available space. 

Double-shell tank: 
Dome; 
Reinforced concrete; 
Outer Carbon-steel shell; 
Inner Carbon-steel shell; 
Annulus (3-foot space between shells); 
Risers; 
Solid waste; 
Liquid waste; 
Empty/available space. 

Sources: GAO and DOE. GAO-15-40. 

[End of figure] 

Beginning in the 1970s, to minimize the risks of leaking tanks, DOE 
began transferring much of the liquid waste from the SSTs to the DSTs. 
This process consisted of removing (1) the liquid (more mobile) waste 
first and then (2) the rest of the waste from the SSTs, thereby 
effectively emptying the SSTs. The first part of this process--
removing liquid waste from the SSTs and transferring it to DSTs--is 
referred to as interim stabilization and was largely completed by 
2005.[Footnote 6] The interim stabilization for each tank was 
considered complete, and DOE could stop pumping liquid waste, when DOE 
and Ecology agreed that the following criteria were met[Footnote 7]: 

* less than 5,000 gallons of free standing liquid waste remained, 

* less than 50,000 gallons of drainable liquid waste (liquid waste 
interspersed within the solid waste) remained, and: 

* pumping was no longer effective. 

The second part of the process--removing the remaining waste from the 
SSTs and transferring it to DSTs--began in 2003 and is still under 
way. This work is governed by two main compliance agreements: (1) the 
1989 Hanford Federal Facility Agreement and Consent Order, or Tri-
Party Agreement (TPA),[Footnote 8] an agreement between DOE, Ecology, 
and the Environmental Protection Agency and (2) a 2010 consent decree. 
Under the consent decree, DOE is required to retrieve waste from 19 
tanks (transferring the waste to DSTs) and begin operating the WTP and 
treating waste by 2022. The TPA requires DOE to retrieve the waste 
from all of the SSTs by no later than 2040 and to have all waste 
retrieved from all DSTs and treated by 2047. As of July 2014, DOE had 
completed the retrieval and transfer of waste from 12 of the SSTs into 
DSTs. 

In addition to concerns about tank leaks, DOE is also monitoring tanks 
for water intrusion from rain and melting snow that can enter the 
underground tanks through the piping connected to them. Water 
intrusions can increase the consequences of waste leaks and also mask 
tank leaks, as waste levels in the tanks could remain the same even as 
waste was leaking into the ground. According to DOE documented reviews 
of the tanks, DOE has been aware of water intrusions in some SSTs 
since the 1980s and has detected intrusions into the annulus of some 
DSTs since the 1990s. 

Contents of the Tanks: 

The waste stored in the tanks at Hanford generally sits in layers and 
comes in a variety of forms, depending on its physical and chemical 
properties. The waste in the tanks takes the following three main 
forms, which are illustrated in figure 2: 

* Supernate. Above or between the denser layers may be liquids 
composed of water and dissolved salts that are called supernate. 
Supernate comprises 21.4 million gallons of the waste in the Hanford 
tanks and about 24 percent of the radioactivity. 

* Saltcake. Above the sludge may be water-soluble components, such as 
sodium salts, that crystallize or solidify out of the waste solution 
to form a moist sandlike material called saltcake. Saltcake comprises 
24 million gallons of the waste in the Hanford tanks and about 20 
percent of the radioactivity. 

* Sludge. The denser, water-insoluble components of the waste 
generally settle to the bottom of the tank to form a thick layer known 
as sludge, which has the consistency of peanut butter. Although sludge 
makes up the smallest portion of waste in the Hanford tanks (10.7 
million gallons), it comprises over half (56 percent) of the total 
radioactivity in the tank waste. 

Figure 2: Composition of Waste in Hanford Tanks, as of May 2014: 

[Refer to PDF for image: illustration] 

Supernate (liquid): 
Volume (million gallons): 21.4; 
Approximate percentage of total radioactivity: 24%. 

Saltcake (solid): 
Volume (million gallons): 24; 
Approximate percentage of total radioactivity: 20%. 

Sludge (solid): 
Volume (million gallons): 10.7; 
Approximate percentage of total radioactivity: 56%. 

Source: DOE. GAO-15-40. 

Note: Supernate refers to liquids composed of water and dissolved 
salts. Saltcake refers to water-soluble components, such as sodium 
salts, that crystallize or solidify out of the waste solution to form 
a moist sandlike material, and sludge is a denser, water-insoluble 
component of the waste that generally settles to the bottom of the 
tank to form a thick layer that has the consistency of peanut butter. 

[End of figure] 

The tanks contain a complex mix of radioactive and hazardous waste in 
both liquid and solid form. About 46 different radioactive elements--
by-products of chemically separating plutonium from uranium for use in 
nuclear weapons--represent the majority of the radioactivity currently 
in the tanks. Some of these elements lose most of their radioactivity 
in a relatively short time, while others will remain radioactive for 
millions of years. The rate of radioactive decay is measured in half-
lives, that is, the time required for half the unstable atoms in a 
radioactive substance to disintegrate, or decay, and release their 
radiation. The half-lives of radioactive tank constituents differ 
widely. The vast majority (98 percent) of the radioactivity of the 
tank waste comes from two elements, strontium-90 and cesium-137, which 
have half-lives of about 29 and 30 years, respectively. The remaining 
radioactive elements, which account for about 2 percent of the waste's 
total radioactivity, have much longer half-lives. For example, the 
half-life of technetium-99 is 213,000 years, and that of iodine-129 is 
15.7 million years. 

The hazardous wastes in the tanks include various metal hydroxides, 
oxides, and carbonates. Some of the chemicals--including acids, 
caustic sodas, solvents, and toxic heavy metals, such as chromium--
came from chemically reprocessing spent nuclear fuel to extract 
weapons-grade plutonium. Altogether, about 240,000 tons of chemicals 
were added to the tanks from the 1940s to the mid-1980s.[Footnote 9] A 
majority of the chemicals were added to neutralize acids in the waste. 
Other chemicals, such as solvents and several organic compounds, were 
added during various waste extraction operations to help recover 
selected radioactive elements (uranium, cesium, and strontium) for 
reuse. These hazardous chemicals are dangerous to human health, and 
they can remain dangerous for thousands of years. 

Tank Regulations and Oversight: 

DOE's storage of waste at Hanford is governed by federal and 
Washington State laws and regulations. DOE's tank waste cleanup 
program at Hanford is governed by, among other things, the Resource 
Conservation and Recovery Act of 1976, as amended (RCRA), as 
implemented by Washington under its Hazardous Waste Management Act, 
and the Atomic Energy Act of 1954. RCRA governs the treatment, 
storage, and disposal of hazardous waste and the non-radioactive 
hazardous waste component of mixed waste. The tank waste at Hanford is 
considered mixed waste because it contains both chemically hazardous 
and certain radioactive materials.[Footnote 10] For the chemically 
hazardous waste in the tanks, as shown in figure 3, RCRA establishes 
the following three key requirements (subject to certain limited 
exceptions): 

* Tank integrity. Under RCRA, tanks must have secondary containment--
that is, a second shell--and an integrity assessment must be conducted 
by a qualified professional engineer to assess whether the tanks are 
fit for use.[Footnote 11] 

* Leak detection. RCRA requires a leak detection system to be in place 
for each tank that will detect the failure of either the primary and 
secondary containment structure or any release of hazardous waste in 
the secondary containment system within 24 hours, or at the earliest 
practicable time. Data gathered from monitoring and leak detection 
equipment must be inspected at least once each operating day to ensure 
that the tank system is being operated according to its design. 

* Leak response. Within 24 hours after detection of a leak or, if the 
owner or operator demonstrates that that is not possible, at the 
earliest practicable time, RCRA requires the tank owner, among other 
things, to remove as much of the hazardous waste or accumulated liquid 
as is necessary to prevent further release of hazardous waste to the 
environment and allow inspection and repair or closure of the tank 
system to be performed. If the release was to a secondary containment 
system, all released materials must be removed within 24 hours or in 
as timely a manner as is possible to prevent harm to human health and 
the environment. 

Figure 3: Resource Conservation and Recovery Act of 1976 Requirements 
for Underground Tanks: 

[Refer to PDF for image: illustration] 

Resource Conservation and Recovery Act of 1976: 

Tank Integrity: 
* Must have secondary containment; 
* Must be assessed for integrity. 

Leak Detection: 
* Must have a leak detection system that can detect a leak at the 
earliest practicable time; 
* Must inspect tank data at least once each day. 

Leak Response for tanks deemed unfit or leaking: 
* Must remove from service immediately; 
* Must generally report leak to regulator within 24 hours of detection; 
* Must remove waste to prevent further leaks within 24 hours or as 
soon as practicable. 

Sources: GAO and RCRA. GAO-15-40. 

Note: Secondary containment refers to, for example, a second carbon-
steel lining, or shell, within the outer concrete housing of a tank to 
provide secondary containment of the waste. 

[End of figure] 

To address these RCRA requirements, DOE conducts a variety of 
assessments and monitoring activities. Regarding tank integrity, DOE 
conducted integrity assessments for the SSTs in 2002 and the DSTs in 
2006. To address the leak detection monitoring requirement, for the 
DSTs, DOE has one waste level monitor installed inside the primary 
tank space and three waste level monitors in the annulus. These 
monitors collect waste level data on a daily basis. For the SSTs, 
because they were built decades before the enactment of RCRA, they do 
not have secondary containment. As such, DOE has determined that the 
SSTs cannot readily be made compliant with current regulations and 
these tanks were determined to be "unfit for use." Under RCRA, unfit 
for use tanks are no longer allowed to store waste and must generally 
be closed. DOE plans to ultimately close the tank farms in accordance 
with tank farm closure permits to be issued by Ecology. In the 
meantime, DOE monitors the SSTs under modified operating procedures, 
including modified leak detection and monitoring requirements as 
agreed with Ecology.[Footnote 12] Under these modified procedures and 
additional DOE operating specifications, the majority of the SSTs are 
required to be monitored weekly, quarterly, or annually for leaks and 
intrusions depending on DOE's knowledge of the condition of the tanks 
and the type and amount of waste inside them. In 2009, DOE developed 
an emergency pumping guide outlining procedures for responding to 
leaks in DSTs, to implement the RCRA requirement that the tank system 
owner/operator must within 24 hours after detection of the leak or, at 
the earliest practicable time, remove as much waste as necessary to 
prevent further releases. 

Condition of Tanks Is Worse than Assumed under DOE's Current Schedule 
for Retrieving Tank Waste: 

DOE's recent assessments of the SSTs and DSTs determined that they are 
in worse condition than DOE had assumed when developing its 2011 
System Plan schedule for emptying the tanks.[Footnote 13] For SSTs, 
following a series of assessments in 2013 and 2014, DOE concluded that 
water is intruding into at least 14 SSTs and that at least 1, T-111, 
is actively leaking. For DSTs, DOE concluded in 2012 that waste was 
leaking from the primary shell in tank AY-102 and subsequently found 
that 12 other DSTs have construction flaws similar to those that 
contributed to the leak in AY-102. According to recent DOE reviews of 
the tank, water has intruded into the space between the inner and 
outer shells of tank AY-102 and another tank nearby. 

Condition of SSTs Is Worse Than Previously Assumed, with 1 Leaking and 
Water Infiltrating at Least 14: 

In 2013 and 2014, DOE completed assessments of the SSTs and found that 
they are in worse condition than had been previously believed. As of 
2005, DOE and Ecology agreed that the interim stabilization process 
had reduced the risk of leaks in SSTs, which led DOE, with concurrence 
from Ecology, to reduce the required frequency of monitoring from 
daily to quarterly or annually depending on the condition of the tank 
and the amount of liquid waste inside. However, concerns about 
historical water intrusions led DOE to reexamine all 149 SSTs in 2011 
to determine the extent of the intrusions. This reexamination, which 
concluded in 2014, confirmed that water was intruding into at least 14 
tanks and that the intrusions were adding from less than 10 to more 
than 2,000 gallons of water annually to each tank. According to a DOE 
report on intrusions, water intrusion creates additional liquid waste 
in the tanks as the new water becomes contaminated by the waste in the 
tanks. Furthermore, water intrusions can affect the level of tank 
waste, making it difficult to ensure that a tank is not leaking. 
Officials on an expert panel, convened by DOE in 2009 to assess the 
condition of the SSTs, concluded in August 2014 that significant 
amounts of drainable liquid still remain in the SSTs and removing that 
liquid and preventing future water intrusions should be a high 
priority. 

In addition to increasing waste levels in several tanks, DOE found in 
2013 that waste levels appeared to be decreasing in several tanks and 
subsequently confirmed that at least one SST, tank T-111, was actively 
leaking waste into the ground.[Footnote 14] DOE's report on the tank 
leak indicates that the leak likely began in 2010. According to DOE 
officials, waste is leaking at a rate of approximately 640 gallons 
annually, and DOE continues to monitor the leak in tank T-111. DOE has 
also confirmed that T-111 is one of the SSTs experiencing intrusions. 
Though the tank is leaking, according to DOE officials, DOE is not 
required by regulation to remove the liquid waste from T-111 because 
the amount of liquid waste in the tank does not exceed the interim 
stabilization criteria and because there are no current requirements 
to reestablish compliance with interim stabilization criteria if 
conditions in a tank change.[Footnote 15] 

Condition of DSTs Is Worse Than Previously Assumed, with 12 Tanks 
Having Flaws Similar to the Leaking Tank and Water Infiltrating at 
Least 2 Tanks: 

Regarding DSTs, prior to the discovery of the leak in AY-102 in 2012, 
DOE had assumed that all DSTs were sound for storing waste. In 2006, 
all 28 DSTs were examined by a qualified professional engineer, as 
required under RCRA, and deemed fit for use. In a 2010 report on the 
integrity of the DSTs, DOE reaffirmed their fitness for continuing to 
store waste. However, after the 2012 leak was discovered, in March 
2014, DOE reported the discovery of a second accumulation of waste in 
a different location in the annulus of tank AY-102. As of August 2014, 
DOE reported that more than 35 gallons of waste had leaked from the 
primary shell of AY-102 into the annulus at a rate of about 3 gallons 
per month. To date, no waste has been detected outside of the 
secondary tank shell, according to DOE officials. 

DOE is still investigating the factors that caused the AY-102 leak and 
the extent to which other DSTs may be susceptible to the same factors. 
DOE reported in October 2012 that tank construction flaws and 
corrosion in the bottom of the tank stemming from the type of waste 
and the sequence in which it was loaded into the tank AY-102 were the 
likely causes for the leak in AY-102.[Footnote 16] According to a 2014 
expert panel reviewing the leak, corrosion was among the likely causes 
of the leak. The panelists concluded that the corrosion likely 
occurred as a result of water collecting under the tank before it was 
fully enclosed and during a 6-year outage of the ventilation system in 
the annulus from 1991-1997, rather than as a result of the waste 
loading sequence. Beginning in 2013, DOE examined the other 27 DSTs to 
determine the extent to which they had construction flaws similar to 
AY-102. In a series of reports issued between July 2013 and February 
2014, DOE reported that at least 12 of the other 27 DSTs have similar 
construction flaws. However, DOE has not yet assessed the extent to 
which the factors that led to corrosion that may have caused the leak 
in AY-102 are also present in the remaining 27 DSTs. 

DOE also determined in 2012 that water was likely intruding into the 
annulus of at least 2 DSTs, including the leaking tank AY-102. This is 
not the first time DOE has detected intrusions in the DSTs. In 1991, 
DOE first reported unexplained moisture in DSTs AY-101 and AY-102, the 
oldest DSTs on the site. Since then, DOE has periodically monitored 
and reviewed the status of this moisture, concluding in 2001 that 
water intrusions through corroded tank equipment were the likely 
cause. After removing some of the suspected connections and further 
inspecting the two tanks with video cameras, DOE concluded in 2009 
that the water intrusions had stopped. However, routine inspections of 
the tanks in 2012 revealed that water may still be seeping into the 
annulus of both tanks. According to DOE officials, an investigation 
into this issue is ongoing. In the 2011 System Plan, DOE stated that 
the DSTs play an integral role in the tank waste cleanup effort. 

DOE Has Taken and Planned Several Actions to Respond to Recent Leaks 
and Intrusions, Including Modifying Its Tank Monitoring and Inspection 
Procedures: 

Following the discovery of the leaks in tanks T-111 and AY-102, and 
water intrusions in some SSTs, DOE has undertaken or planned several 
actions. For the SSTs, DOE has, among other things, performed 
additional inspections and temporarily increased the frequency of 
monitoring the tank waste levels from annually or quarterly to 
monthly. For the DSTs, DOE has conducted additional inspections, 
modified its inspection procedures, convened an expert panel to 
examine its DST leak detection process, and developed a pumping plan 
for AY-102. 

For SSTs, DOE Has Conducted Additional Inspections and Modified Its 
Tank Monitoring Procedures: 

In response to the leak in tank T-111 and intrusions in other SSTs, 
DOE has taken several actions, including the following: 

* Increased monitoring and conducted additional inspections. In 2012, 
when the leak was initially discovered in T-111, DOE increased the 
leak detection monitoring for the tank from annually to weekly. In 
addition, for 19 other SSTs that were under review for decreasing 
liquid levels, DOE increased the leak monitoring frequency from 
annually or quarterly (depending on the tank) to monthly. DOE 
maintained weekly leak detection monitoring for T-111, but in April 
2014 went to monthly monitoring. According to a DOE official, the 
monthly monitoring was deemed sufficient to understand the 
relationship between the intrusion and the leak and the monitors are 
always in place and data are collected more frequently than the 
monthly requirement. Additionally, monitoring procedures for the other 
SSTs have since returned to their normal frequency of annual 
monitoring for intrusions only. For the 14 SSTs with confirmed 
intrusions and the 5 that do not meet interim stabilization criteria, 
DOE has placed them on a quarterly monitoring regime. DOE also 
performed additional inspections of the tanks with decreasing liquid 
levels but, after further analysis, concluded that none of those tanks 
were likely leaking.[Footnote 17] 

* Modified waste analysis procedures. As noted above, as part of its 
reexamination of SST waste levels, DOE discovered flaws in its methods 
for reviewing data on SST tank waste levels that it uses to monitor 
the tanks for leaks and intrusions. DOE officials determined that 
their method for reviewing tank waste data was flawed and masked 
increases and decreases in the waste levels in the SSTs that may have 
been due to water intrusions and leaks. In response, DOE modified its 
waste level monitoring methodology and procedures for analyzing waste 
data. For example, in 2013, DOE established a systems engineering 
group responsible for monitoring waste levels in all tanks. DOE is 
also developing training based on the modified waste level monitoring 
methodology, including guidance on tank waste data interpretation, 
trend analysis, documentation requirements, and review and approval 
procedures for changes in waste levels. 

For DSTs, DOE Has Conducted Additional Inspections, Convened an Expert 
Panel, and Developed a Pumping Plan for AY-102: 

Following the discovery of the leak in AY-102, DOE has taken or 
planned several actions including the following: 

* Conducted additional inspections and modified inspection procedures. 
Following the discovery of the leak in AY-102, DOE performed video 
inspections of the annulus of 6 of the 12 DSTs with construction 
histories similar to AY-102. The video inspections, which according to 
a DOE official in the past only examined a portion of the annulus, 
examined between 95 and 100 percent of the annulus in each of the 
tanks.[Footnote 18] According to DOE officials, DOE plans to continue 
these full video inspections for the remaining 21 DSTs over the next 
several years. In addition, in April 2014, DOE formally modified its 
inspection procedures by shortening the time between inspections from 
every 5 to 7 years to every 3 years. In addition, in June 2014, DOE 
began soliciting proposals to award a contract for another independent 
assessment of the integrity of the DSTs to be completed in 2016. 

* Convened expert panel. DOE convened an expert panel to review its 
DST leak detection procedures and make recommendations for 
improvement. This panel met three times and developed preliminary 
findings and suggested program improvements. One of the preliminary 
findings was that additional DST leaks cannot be ruled out given 
current DST integrity program limitations and the extended schedule 
for the construction and operation of the WTP. During the panel's most 
recent meeting in August 2014, members of the panel said that more 
analysis needs to be done to understand the factors that led to the 
leak in AY-102 and the extent to which the other DSTs are susceptible 
to similar factors. 

* Developed AY-102 pumping plan. If a leak is detected, RCRA 
requirements call for the hazardous waste or accumulated liquid to be 
retrieved from the tank to the extent necessary to prevent further 
releases within 24 hours or as soon as practicable and to allow 
inspection and repair. In addition, DOE's emergency pumping guide 
outlines steps to "immediately" remove waste from a leaking DST. DOE 
officials stated that this guide did not anticipate a leak from the 
bottom of the primary shell of a tank such as the one occurring in AY-
102. Instead, DOE proposed that the waste not be retrieved until at 
least 2016, maintaining that that was as soon as it could practicably 
retrieve the waste due to concerns that doing so would cause the 
temperature of the tank to rise to dangerous levels without liquid 
waste to act as a cooling agent. In addition, DOE noted in its plan 
that it needed to procure and install additional equipment in order to 
pump waste out of the tank. In response to DOE's submitted plan, 
Ecology issued an administrative order to compel DOE to begin pumping 
waste out of AY-102 by September 1, 2014, and retrieve enough waste to 
allow for an inspection to determine the cause of the leaks no later 
than December 1, 2016. The two sides reached a settlement agreement in 
September 2014, under which DOE is to begin pumping the waste out of 
AY-102 no later than March 2016 and to have the waste removed by March 
2017--over 5 years after the leak was first discovered.[Footnote 19] 

DOE's Current Waste Retrieval Schedule Does Not Account for the 
Worsening Condition of the Tanks or WTP Delays: 

DOE's current schedule for retrieving the waste from the tanks 
(developed in 2011), which includes transferring waste from SSTs to 
DSTs and treating the waste in the DSTs, does not take into account 
the worsening conditions of the tanks or the delays in the 
construction of the WTP. The leak in AY-102 combined with planned 
waste transfers has reduced the available DST space, and DOE's plans 
to create additional space remain uncertain. Future leaks and 
intrusions, which become more likely as the tanks' conditions worsen, 
would place additional demands on the limited available DST space, and 
it is unclear how DOE would respond. According to DOE, recent efforts 
to evaporate some of the water from the waste have already freed up 
750,000 gallons of DST space. In addition, in March 2014, DOE 
announced that it plans to indefinitely delay construction of the key 
WTP facilities needed to retrieve and treat tank waste for disposal 
until technical issues are resolved. As a result, it is unclear how 
long waste will remain in the tanks. However, without an analysis of 
the extent to which the factors which may have led to the leak in AY-
102 are present in the other DSTs, DOE cannot be sure how long its 
DSTs will be able to safely store the waste. 

DOE's Retrieval Schedule Does Not Account for the Worsening Condition 
of Tanks and Growing Demand on the Limited DST Space: 

The free space available in the DSTs is currently limited, and 
operational requirements and planned transfers from the SSTs constrain 
DOE's ability to respond to future emergencies, such as leaks. As 
shown in figure 4, SSTs hold a total of about 29 million gallons of 
waste and, as noted above, have been deemed "unfit for use" under RCRA 
and therefore cannot be used for storing additional waste.[Footnote 
20] The DSTs currently hold a total of about 27 million gallons of 
waste, leaving about 5.3 million gallons of available space for waste 
to be transferred from other tanks. 

Figure 4: Approximate Configuration of Space Usage in Hanford's 177 
Tanks, as of May 2014: 

[Refer to PDF for image: illustration] 

All 149 single-shell tanks: 
Volume: 
Total waste: 29 million gallons. 

All 28 double-shell tanks: 
Volume: 
Total waste: 27 million gallons; 
Empty space: 5.3 million gallons. 

Source: DOE. GAO-15-40. 

Note: Single-shell tanks (SST) have been declared unfit for use and 
cannot readily be made compliant with current regulations. 

[End of figure] 

However, DOE policy and planned waste transfers further reduce the 
amount of space available. As shown in figure 5, about 2.5 million 
gallons of the 5.3 million gallons of empty space is reserved by DOE 
for safety purposes, for emergency space if necessary, and to enable 
DOE to more easily transfer waste among tanks. In addition, planned 
waste transfers from SSTs (about 1.8 million gallons) and AY-102 
(about 800,000 gallons) will further reduce available DST space (see 
figure 5). Specifically, DOE plans to first empty an additional 15 
SSTs, containing a total of approximately 1.8 million gallons of 
waste, into DSTs by 2022. Second, DOE plans to pump all of the 
approximately 800,000 gallons of waste in AY-102 into other DSTs no 
early than 2016. As a result of these planned transfers and 
operational requirements, about 200,000 gallons of storage space is 
actually available in the DSTs. DOE officials said that they plan to 
restart an evaporator facility at Hanford that could reduce the 
overall amount of waste in the tanks and result in 3 million gallons 
of additional DST space. This facility, which began operating in 1973 
and was designed to operate for 25 years, has not operated since 2010 
and was only recently restarted by DOE.[Footnote 21] According to DOE 
officials, since restarting the evaporator in September 2014, DOE has 
reduced the waste volume by over 750,000 gallons. 

Figure 5: Current and Planned Usage of Empty Double-shell Tank Space 
at Hanford, as of May 2014: 

[Refer to PDF for image: illustration] 

Empty space: 5.3 million gallons: 
Reserved by DOE for emergencies and other operational requirements: 
2.5 million gallons; 
Planned waste transfer from AY-102: 0.8 million gallons; 
Planned waste transfers from single-shell tanks: 1.8 million gallons; 
Available: 0.2 million gallons. 

Source: DOE. GAO-15-40. 

[End of figure] 

In addition to these scheduled waste transfers, future leaks and 
intrusions, which become more likely as the tanks' condition worsens, 
would require DOE to pump more waste and place additional demands on 
the limited remaining DST space. Both DOE and Ecology have reported 
that leaving waste in the tanks past their design life increases the 
risk of leaks over time. Similarly, the panel of experts that DOE 
convened to review the AY-102 leak concluded in May 2014 that, given 
the extended time frames for the cleanup mission and the growing 
concerns about the integrity of the tanks, additional leaks cannot be 
ruled out. Such leaks and intrusions could place further demands on 
the available space in the DSTs because when leaks occur, DOE is 
required by RCRA and associated tank monitoring and pumping 
requirements, as described below, to pump hazardous waste from these 
tanks into the already limited space available in the nonleaking DSTs. 
For example, if a leak is detected in a SST that exceeds interim 
stabilization criteria (i.e., it has more than 5,000 gallons of 
freestanding liquid or 50,000 gallons of drainable liquid waste), DOE 
is then required by modified leak detection and monitoring 
requirements as agreed with Ecology to install emergency pumping 
equipment and begin pumping the liquid waste out of the tank as soon 
as practicable.[Footnote 22] At least five SSTs currently fall into 
this category because they have exceeded the amount of liquid waste 
allowed under interim stabilization (likely as a result of water 
intrusion, according to DOE officials). Similarly, if another DST 
begins to leak, DOE is required by RCRA to remove the hazardous waste 
or accumulated liquid from the tank to the extent necessary to prevent 
further releases within 24 hours or as soon as practicable. The only 
RCRA compliant alternative currently available for storing this 
retrieved waste is into the limited space available in the nonleaking 
DSTs. According to the DOE official responsible for managing Hanford's 
tank operations, given the current constraints on available DST space, 
if another DST was to fail before additional DST space is available, 
DOE would have nowhere to move the waste. However, according to DOE 
officials, DOE currently has no plans to build new tanks and estimates 
that it would take about 8 years before the new tanks would be 
available to receive waste. 

DOE's Retrieval Schedule Does Not Account for Recently Acknowledged 
WTP Delays, and the Extent to Which the Tanks Can Continue to Safely 
Store Waste Is Unknown: 

In March 2014, DOE reported that unresolved technical issues could 
prevent the WTP from operating safely as currently designed. Under the 
existing TPA and consent decree, DOE is required to begin operating 
the WTP and treating waste in 2022, to have retrieved all waste from 
the SSTs by 2040, and to have all waste retrieved from all DSTs and 
treated by 2047. DOE reported in March 2014 that, until the technical 
uncertainties are resolved, it is not possible to predict when the WTP 
will be completed. In addition, DOE has proposed building at least two 
new waste processing facilities to allow waste treatment to begin 
while it is resolving the WTP's technical uncertainties. One of the 
two facilities would, if constructed, treat some of the low-activity 
waste in the tanks. According to DOE officials, this facility would be 
operational no later than December 2022 and would make available about 
1.3 million gallons of DST space after the first 3 years of operation. 
[Footnote 23] 

DOE has not estimated the impact of the WTP delay on its tank 
management plans, but delays in the schedule to retrieve waste from 
the SSTs are already occurring. Before its decision to delay the WTP, 
in a series of letters to Ecology from November 2011 to September 
2014, DOE stated that it would likely miss the scheduled milestones in 
the consent decree, including milestones for completing the WTP and 
emptying waste from the SSTs.[Footnote 24] DOE further reported in 
March 2014 that delays in the WTP will affect the schedule for 
retrieving waste from the tanks but that, until the technology it is 
developing to treat the tank waste in the WTP can be demonstrated to 
work as intended, it is impossible to estimate what the impact will be 
on the retrieval of waste from the tanks. DOE cannot reliably update 
its scheduled deadlines for retrieving waste from tanks without 
considering the impact of the WTP delay. 

The technical challenges at WTP and the continued uncertainty about 
the schedule for retrieving and treating the waste mean that the 
overall cleanup mission will continue to depend on the integrity of 
the DSTs. However, the extent to which the DSTs can continue to safely 
store waste is unknown. In the 2011 System Plan, DOE stated that the 
DSTs play an integral role in the tank waste cleanup effort.[Footnote 
25] Both a DOE report and members of DOE's 2014 expert panel, convened 
to examine the integrity of the DSTs, have stated that corrosion is a 
threat to DST integrity, and the expert panel also highlighted 
deficiencies in DOE's understanding of corrosion in all of the DSTs. 
The panel officials concluded in August 2014 that more work needs to 
be done to better understand the factors that led to the corrosion in 
AY-102. However, as noted previously, DOE has not examined the other 
DSTs for the same corrosion factors that may have lead to corrosion in 
AY-102 and therefore lacks information about the extent to which the 
other 27 DSTs may also be susceptible to similar corrosion. As a 
result, DOE lacks assurance that these tanks will be available for use 
through the end of the cleanup mission, as DOE's 2011 System Plan 
contemplates, and cannot reliably update its schedule for emptying the 
SSTs. 

All of the SSTs and DSTs will be well beyond their design life before 
they are emptied. Of the 137 SSTs that are still storing waste, all 
are currently decades beyond their design life, and all but 13 of them 
would be at least 40 years beyond their design life before being 
emptied under DOE's existing schedule for emptying the tanks. While 
the design life of the DSTs varies, 4 of the 28 DSTs are already past 
their design life, and under the current TPA milestones, all DSTs are 
expected to be well beyond their design life by the time they are 
scheduled to be emptied. (See appendix I and III for design life data 
for each SST and appendix II for design life data for each DST. Figure 
6, an interactive figure in appendix I, shows a timeline of all 
Hanford SSTs. Appendix III, table 1, is the noninteractive, printable 
version of figure 6.) 

DOE does not have plans to construct additional storage to address its 
long-term storage needs and the risks presented by the aging tanks. 
DOE has looked at options for building new tanks to address the 
constraints on DST space if the cleanup mission were to take 
significantly longer than currently planned. DOE has developed a rough 
estimate of the time and cost that would be required to build 
additional tanks. Specifically, in 2011, Ecology asked DOE to include 
the option of building new tanks in an update to its System Plan. In 
response, DOE developed a rough estimate for how much it would cost to 
build 8 additional storage tanks, if necessary. DOE estimated that 
doing so would cost about $800 million and would take about 8 years to 
complete. According to the System Plan, this was a rough order of 
magnitude estimate and a more detailed estimate would be required 
before a decision to build new tanks could be considered. In 2012, DOE 
issued its final EIS for Hanford, which included discussion of several 
tank waste cleanup alternatives that would have involved building 
additional DSTs as part of the response to delayed cleanup schedules. 
[Footnote 26] 

Conclusions: 

DOE has recently taken and has plans for taking additional steps to 
improve its tank monitoring and inspection procedures at Hanford and 
is in the process of reassessing the integrity of the DSTs at the 
site. However, these steps do not address the longer-term concerns 
about leaving waste in the aging tanks indefinitely. Specifically, DOE 
lacks specific information about the condition of the DSTs, including 
whether the factors that may have led to corrosion contributed to the 
leak in AY-102 may affect other tanks which are already many years 
beyond their design life. Given the current condition of the tanks, it 
is unclear how long they can safely store the waste. Moreover, 
following the leak in AY-102, available DST space--which is essential 
to DOE's tank management plans--is increasingly limited, constraining 
DOE's ability to respond to potential future leaks and protect human 
health and the environment. It is unclear, however, whether DOE has 
enough DST space available to address current and future waste 
transfers. As we mentioned earlier, DOE officials responsible for 
managing Hanford's tank operations said that given the current 
constraints on available DST space, if another DST was to fail, DOE 
may have nowhere to move the waste. Additional space, either from 
treating waste or building new tanks, is still at least 8 years away 
assuming DOE's schedule estimates for these projects are accurate, 
although DOE has begun recently to free up some DST space by 
restarting its evaporator facility. Notably, responding to tank leaks 
can take many years even when there is available DST space, as the 
leak in AY-102 illustrates. By developing a more a detailed and up-to-
date schedule estimate for emptying the tanks, DOE will be in a better 
position to consider its waste storage needs and need for new tanks. 
As the tanks age, there will be a continued and increasing risk of 
tank failure that can only be permanently addressed by emptying the 
existing SSTs and DSTs. Given the long-standing technical problems 
facing the WTP, it is highly uncertain when waste treatment operations 
could begin to create significant available space in the DSTs. 
However, creating capacity to move some of this waste to RCRA-
compliant tanks would allow DOE to respond to future leaks and ensure 
it has sufficient space for treatment operations once WTP is completed. 

Recommendations for Executive Action: 

* To ensure that DOE's long-term plans for storing waste in the 
existing SSTs and DSTs at Hanford consider the condition of the tanks 
and the WTP construction delay, we recommend that the Secretary of 
Energy take the following three actions: 

* Assess the extent to which the factors that may have led to 
corrosion in AY-102 are present in any of the other 27 DSTs. 

* Update the schedule for retrieving waste from the tanks, taking into 
consideration: 

- the impact of the delays in the WTP, 

- the risks associated with continuing to store waste in aging tanks, 
and: 

- an analysis of available DST space. 

* Assess the alternatives for creating new RCRA-compliant tank space 
for the waste from the SSTs, including building new DSTs. 

Agency Comments and Our Evaluation: 

We provided DOE with a draft of this report for its review and 
comment. In its written comments, reproduced in appendix IV, DOE 
agreed with the report and its recommendations. DOE also provided 
technical comments that were incorporated, as appropriate. 

As agreed with your office, unless you publicly announce the contents 
of this report earlier, we plan no further distribution until 30 days 
from the report date. At that time, we will send copies of this report 
to the appropriate congressional committees; the Secretary of Energy; 
the Director, Office of Management and Budget; and other interested 
parties. In addition, this report will be available at no charge on 
the GAO website at [hyperlink, http://www.gao.gov]. 

If you or your staff members have any questions about this report, 
please contact me at (202) 512-3841 or trimbled@gao.gov. Contact 
points for our Offices of Congressional Relations and Public Affairs 
may be found on the last page of this report. GAO staff who made major 
contributions to this report are listed in appendix V. 

Sincerely yours, 

Signed by: 

David C. Trimble: 
Director, Natural Resources and Environment: 

[End of section] 

Appendix I: Timeline of Hanford Single-Shell Tanks: 

Figure 6: Timeline of Hanford Single-shell Tanks: 

[Refer to PDF for image: Interactive Graphic] 

Instructions: Online, roll your mouse over each year in the figure for 
additional information. 

For a printable version, see appendix III, page 30. 

Source: GAO analysis of DOE data. GAO-15-40. 

[A] These dates for retrieving the waste from the tanks are based on 
the Department of Energy's (DOE) 2011 Office of River Protection 
System Plan. Although DOE had planned to have completed the retrieval 
of waste from all tanks in the C Farm by 2013, that work is still 
ongoing with five tanks yet to be retrieved. An update to this plan is 
scheduled to be released by DOE in the beginning of fiscal year 2015. 

[End of figure] 

[End of section] 

Appendix II: Timeline of Hanford Double-Shell Tanks: 

Figure 7 shows design life data for double-shell tanks. 

Figure 7: Timeline of Hanford Double-shell Tanks: 

[Refer to PDF for image: timeline] 

Tank: AY-101; 
Year the tank began operating: 1971; 
Years the tank was designed to hold waste: 40; 
Years past its design life that the tank is scheduled to hold waste: 
38; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AY-102; 
Year the tank began operating: 1971; 
Years the tank was designed to hold waste: 40; 
Years past its design life that the tank is scheduled to hold waste: 
38; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AZ-101; 
Year the tank began operating: 1975; 
Years the tank was designed to hold waste: 20; 
Years past its design life that the tank is scheduled to hold waste: 
54; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AZ-102; 
Year the tank began operating: 1975; 
Years the tank was designed to hold waste: 20; 
Years past its design life that the tank is scheduled to hold waste: 
54; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: SY-101; 
Year the tank began operating: 1977; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
22; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: SY-102; 
Year the tank began operating: 1977; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
22; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: SY-103; 
Year the tank began operating: 1977; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
22; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AW-101; 
Year the tank began operating: 1980; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
19; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AW-102; 
Year the tank began operating: 1980; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
19; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AW-103; 
Year the tank began operating: 1980; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
19; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AW-104; 
Year the tank began operating: 1980; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
19; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AW-105; 
Year the tank began operating: 1980; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
19; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AW-106; 
Year the tank began operating: 1980; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
19; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AN-101; 
Year the tank began operating: 1981; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
18; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AN-102; 
Year the tank began operating: 1981; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
18; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AN-103; 
Year the tank began operating: 1981; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
18; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AN-104; 
Year the tank began operating: 1981; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
18; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AN-105; 
Year the tank began operating: 1981; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
18; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AN-106; 
Year the tank began operating: 1981; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
18; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AN-107; 
Year the tank began operating: 1981; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
18; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AP-101; 
Year the tank began operating: 1986; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
13; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AP-102; 
Year the tank began operating: 1986; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
13; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AP-103; 
Year the tank began operating: 1986; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
13; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AP-104; 
Year the tank began operating: 1986; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
13; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AP-105; 
Year the tank began operating: 1986; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
13; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AP-106; 
Year the tank began operating: 1986; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
13; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AP-107; 
Year the tank began operating: 1986; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
13; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Tank: AP-108; 
Year the tank began operating: 1986; 
Years the tank was designed to hold waste: 50; 
Years past its design life that the tank is scheduled to hold waste: 
13; 
All double-shell tanks are scheduled to be emptied by: 2049. 

Source: GAO analysis of DOE data. GAO-15-40. 

[End of figure] 

[End of section] 

Appendix III: Age and Retrieval Schedule for Hanford Single-Shell 
Tanks (Corresponds to figure 6): 

Table 1 lists information contained in interactive figure 6. 

Table 1: Age and Retrieval Schedule for Single-Shell Tanks: 

Tank: T-101; 
Year the tank was placed in service: 1943; 
Planned or actual retrieval of waste (as of 2011): 2032; 
Years past its design life that the tank is scheduled to hold waste: 
64; 
Year the tank was designated as a leaking tank: 1992. 

Tank: T-102; 
Year the tank was placed in service: 1943; 
Planned or actual retrieval of waste (as of 2011): 2030; 
Years past its design life that the tank is scheduled to hold waste: 
62; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: T-103; 
Year the tank was placed in service: 1943; 
Planned or actual retrieval of waste (as of 2011): 2031; 
Years past its design life that the tank is scheduled to hold waste: 
63; 
Year the tank was designated as a leaking tank: 1974. 

Tank: T-104; 
Year the tank was placed in service: 1943; 
Planned or actual retrieval of waste (as of 2011): 2023; 
Years past its design life that the tank is scheduled to hold waste: 
55; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: T-105; 
Year the tank was placed in service: 1943; 
Planned or actual retrieval of waste (as of 2011): 2030; 
Years past its design life that the tank is scheduled to hold waste: 
62; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: T-106; 
Year the tank was placed in service: 1943; 
Planned or actual retrieval of waste (as of 2011): 2032; 
Years past its design life that the tank is scheduled to hold waste: 
64; 
Year the tank was designated as a leaking tank: 1973. 

Tank: T-107; 
Year the tank was placed in service: 1943; 
Planned or actual retrieval of waste (as of 2011): 2033; 
Years past its design life that the tank is scheduled to hold waste: 
65; 
Year the tank was designated as a leaking tank: 1984. 

Tank: T-108; 
Year the tank was placed in service: 1943; 
Planned or actual retrieval of waste (as of 2011): 2032; 
Years past its design life that the tank is scheduled to hold waste: 
64; 
Year the tank was designated as a leaking tank: 1974. 

Tank: T-109; 
Year the tank was placed in service: 1943; 
Planned or actual retrieval of waste (as of 2011): 2031; 
Years past its design life that the tank is scheduled to hold waste: 
63; 
Year the tank was designated as a leaking tank: 1974. 

Tank: T-110; 
Year the tank was placed in service: 1943; 
Planned or actual retrieval of waste (as of 2011): 2022; 
Years past its design life that the tank is scheduled to hold waste: 
54; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: T-111; 
Year the tank was placed in service: 1943; 
Planned or actual retrieval of waste (as of 2011): 2022; 
Years past its design life that the tank is scheduled to hold waste: 
54; 
Year the tank was designated as a leaking tank: 1979. 

Tank: T-112; 
Year the tank was placed in service: 1943; 
Planned or actual retrieval of waste (as of 2011): 2030; 
Years past its design life that the tank is scheduled to hold waste: 
62; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: T-201; 
Year the tank was placed in service: 1943; 
Planned or actual retrieval of waste (as of 2011): 2020; 
Years past its design life that the tank is scheduled to hold waste: 
52; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: T-202; 
Year the tank was placed in service: 1943; 
Planned or actual retrieval of waste (as of 2011): 2020; 
Years past its design life that the tank is scheduled to hold waste: 
52; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: T-203; 
Year the tank was placed in service: 1943; 
Planned or actual retrieval of waste (as of 2011): 2021; 
Years past its design life that the tank is scheduled to hold waste: 
53; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: T-204; 
Year the tank was placed in service: 1943; 
Planned or actual retrieval of waste (as of 2011): 2021; 
Years past its design life that the tank is scheduled to hold waste: 
53; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: B-101; 
Year the tank was placed in service: 1945; 
Planned or actual retrieval of waste (as of 2011): 2033; 
Years past its design life that the tank is scheduled to hold waste: 
63; 
Year the tank was designated as a leaking tank: 1974. 

Tank: B-102; 
Year the tank was placed in service: 1945; 
Planned or actual retrieval of waste (as of 2011): 2032; 
Years past its design life that the tank is scheduled to hold waste: 
62; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: B-103; 
Year the tank was placed in service: 1945; 
Planned or actual retrieval of waste (as of 2011): 2034; 
Years past its design life that the tank is scheduled to hold waste: 
64; 
Year the tank was designated as a leaking tank: 1978. 

Tank: B-104; 
Year the tank was placed in service: 1945; 
Planned or actual retrieval of waste (as of 2011): 2032; 
Years past its design life that the tank is scheduled to hold waste: 
62; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: B-105; 
Year the tank was placed in service: 1945; 
Planned or actual retrieval of waste (as of 2011): 2034; 
Years past its design life that the tank is scheduled to hold waste: 
64; 
Year the tank was designated as a leaking tank: 1978. 

Tank: B-106; 
Year the tank was placed in service: 1945; 
Planned or actual retrieval of waste (as of 2011): 2033; 
Years past its design life that the tank is scheduled to hold waste: 
63; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: B-107; 
Year the tank was placed in service: 1945; 
Planned or actual retrieval of waste (as of 2011): 2033; 
Years past its design life that the tank is scheduled to hold waste: 
63; 
Year the tank was designated as a leaking tank: 1980. 

Tank: B-108; 
Year the tank was placed in service: 1945; 
Planned or actual retrieval of waste (as of 2011): 2032; 
Years past its design life that the tank is scheduled to hold waste: 
62; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: B-109; 
Year the tank was placed in service: 1945; 
Planned or actual retrieval of waste (as of 2011): 2034; 
Years past its design life that the tank is scheduled to hold waste: 
64; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: B-110; 
Year the tank was placed in service: 1945; 
Planned or actual retrieval of waste (as of 2011): 2033; 
Years past its design life that the tank is scheduled to hold waste: 
63; 
Year the tank was designated as a leaking tank: 1981. 

Tank: B-111; 
Year the tank was placed in service: 1945; 
Planned or actual retrieval of waste (as of 2011): 2035; 
Years past its design life that the tank is scheduled to hold waste: 
65; 
Year the tank was designated as a leaking tank: 1978. 

Tank: B-112; 
Year the tank was placed in service: 1945; 
Planned or actual retrieval of waste (as of 2011): 2034; 
Years past its design life that the tank is scheduled to hold waste: 
64; 
Year the tank was designated as a leaking tank: 1978. 

Tank: B-201; 
Year the tank was placed in service: 1945; 
Planned or actual retrieval of waste (as of 2011): 2018; 
Years past its design life that the tank is scheduled to hold waste: 
48; 
Year the tank was designated as a leaking tank: 1980. 

Tank: B-202; 
Year the tank was placed in service: 1945; 
Planned or actual retrieval of waste (as of 2011): 2018; 
Years past its design life that the tank is scheduled to hold waste: 
48; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: B-203; 
Year the tank was placed in service: 1945; 
Planned or actual retrieval of waste (as of 2011): 2019; 
Years past its design life that the tank is scheduled to hold waste: 
49; 
Year the tank was designated as a leaking tank: 1983. 

Tank: B-204; 
Year the tank was placed in service: 1945; 
Planned or actual retrieval of waste (as of 2011): 2019; 
Years past its design life that the tank is scheduled to hold waste: 
49; 
Year the tank was designated as a leaking tank: 1984. 

Tank: C-101; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2012; 
Years past its design life that the tank is scheduled to hold waste: 
41; 
Year the tank was designated as a leaking tank: 1980. 

Tank: C-102; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2013[A]; 
Years past its design life that the tank is scheduled to hold waste: 
42; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: C-103; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2006; 
Years past its design life that the tank is scheduled to hold waste: 
35; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: C-104; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2011; 
Years past its design life that the tank is scheduled to hold waste: 
40; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: C-105; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2013[A]; 
Years past its design life that the tank is scheduled to hold waste: 
42; 
Year the tank was designated as a leaking tank: 2013. 

Tank: C-106; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2003; 
Years past its design life that the tank is scheduled to hold waste: 
32; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: C-107; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2011[A]; 
Years past its design life that the tank is scheduled to hold waste: 
40; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: C-108; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2012; 
Years past its design life that the tank is scheduled to hold waste: 
41; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: C-109; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2012; 
Years past its design life that the tank is scheduled to hold waste: 
41; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: C-110; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2012; 
Years past its design life that the tank is scheduled to hold waste: 
41; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: C-111; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2013[A]; 
Years past its design life that the tank is scheduled to hold waste: 
42; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: C-112; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2012[A]; 
Years past its design life that the tank is scheduled to hold waste: 
41; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: C-201; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2006; 
Years past its design life that the tank is scheduled to hold waste: 
35; 
Year the tank was designated as a leaking tank: 1988. 

Tank: C-202; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2005; 
Years past its design life that the tank is scheduled to hold waste: 
34; 
Year the tank was designated as a leaking tank: 1988. 

Tank: C-203; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2005; 
Years past its design life that the tank is scheduled to hold waste: 
34; 
Year the tank was designated as a leaking tank: 1984. 

Tank: C-204; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2006; 
Years past its design life that the tank is scheduled to hold waste: 
35; 
Year the tank was designated as a leaking tank: 1988. 

Tank: U-101; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2038; 
Years past its design life that the tank is scheduled to hold waste: 
67; 
Year the tank was designated as a leaking tank: 1959. 

Tank: U-102; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2035; 
Years past its design life that the tank is scheduled to hold waste: 
64; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: U-103; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2033; 
Years past its design life that the tank is scheduled to hold waste: 
62; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: U-104; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2039; 
Years past its design life that the tank is scheduled to hold waste: 
68; 
Year the tank was designated as a leaking tank: 1961. 

Tank: U-105; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2037; 
Years past its design life that the tank is scheduled to hold waste: 
66; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: U-106; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2033; 
Years past its design life that the tank is scheduled to hold waste: 
62; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: U-107; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2034; 
Years past its design life that the tank is scheduled to hold waste: 
63; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: U-108; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2036; 
Years past its design life that the tank is scheduled to hold waste: 
65; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: U-109; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2034; 
Years past its design life that the tank is scheduled to hold waste: 
63; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: U-110; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2037; 
Years past its design life that the tank is scheduled to hold waste: 
66; 
Year the tank was designated as a leaking tank: 1975. 

Tank: U-111; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2034; 
Years past its design life that the tank is scheduled to hold waste: 
63; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: U-112; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2038; 
Years past its design life that the tank is scheduled to hold waste: 
67; 
Year the tank was designated as a leaking tank: 1980. 

Tank: U-201; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2035; 
Years past its design life that the tank is scheduled to hold waste: 
64; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: U-202; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2036; 
Years past its design life that the tank is scheduled to hold waste: 
65; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: U-203; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2037; 
Years past its design life that the tank is scheduled to hold waste: 
66; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: U-204; 
Year the tank was placed in service: 1946; 
Planned or actual retrieval of waste (as of 2011): 2036; 
Years past its design life that the tank is scheduled to hold waste: 
65; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: TX-101; 
Year the tank was placed in service: 1947; 
Planned or actual retrieval of waste (as of 2011): 2035; 
Years past its design life that the tank is scheduled to hold waste: 
63; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: TX-102; 
Year the tank was placed in service: 1947; 
Planned or actual retrieval of waste (as of 2011): 2035; 
Years past its design life that the tank is scheduled to hold waste: 
63; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: TX-103; 
Year the tank was placed in service: 1947; 
Planned or actual retrieval of waste (as of 2011): 2034; 
Years past its design life that the tank is scheduled to hold waste: 
62; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: TX-104; 
Year the tank was placed in service: 1947; 
Planned or actual retrieval of waste (as of 2011): 2037; 
Years past its design life that the tank is scheduled to hold waste: 
65; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: TX-105; 
Year the tank was placed in service: 1947; 
Planned or actual retrieval of waste (as of 2011): 2036; 
Years past its design life that the tank is scheduled to hold waste: 
64; 
Year the tank was designated as a leaking tank: 1977. 

Tank: TX-106; 
Year the tank was placed in service: 1947; 
Planned or actual retrieval of waste (as of 2011): 2033; 
Years past its design life that the tank is scheduled to hold waste: 
61; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: TX-107; 
Year the tank was placed in service: 1947; 
Planned or actual retrieval of waste (as of 2011): 2037; 
Years past its design life that the tank is scheduled to hold waste: 
65; 
Year the tank was designated as a leaking tank: 1984. 

Tank: TX-108; 
Year the tank was placed in service: 1947; 
Planned or actual retrieval of waste (as of 2011): 2035; 
Years past its design life that the tank is scheduled to hold waste: 
63; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: TX-109; 
Year the tank was placed in service: 1947; 
Planned or actual retrieval of waste (as of 2011): 2035; 
Years past its design life that the tank is scheduled to hold waste: 
63; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: TX-110; 
Year the tank was placed in service: 1947; 
Planned or actual retrieval of waste (as of 2011): 2038; 
Years past its design life that the tank is scheduled to hold waste: 
66; 
Year the tank was designated as a leaking tank: 1977. 

Tank: TX-111; 
Year the tank was placed in service: 1947; 
Planned or actual retrieval of waste (as of 2011): 2036; 
Years past its design life that the tank is scheduled to hold waste: 
64; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: TX-112; 
Year the tank was placed in service: 1947; 
Planned or actual retrieval of waste (as of 2011): 2035; 
Years past its design life that the tank is scheduled to hold waste: 
63; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: TX-113; 
Year the tank was placed in service: 1947; 
Planned or actual retrieval of waste (as of 2011): 2036; 
Years past its design life that the tank is scheduled to hold waste: 
64; 
Year the tank was designated as a leaking tank: 1974. 

Tank: TX-114; 
Year the tank was placed in service: 1947; 
Planned or actual retrieval of waste (as of 2011): 2038; 
Years past its design life that the tank is scheduled to hold waste: 
66; 
Year the tank was designated as a leaking tank: 1974. 

Tank: TX-115; 
Year the tank was placed in service: 1947; 
Planned or actual retrieval of waste (as of 2011): 2039; 
Years past its design life that the tank is scheduled to hold waste: 
67; 
Year the tank was designated as a leaking tank: 1977. 

Tank: TX-116; 
Year the tank was placed in service: 1947; 
Planned or actual retrieval of waste (as of 2011): 2035; 
Years past its design life that the tank is scheduled to hold waste: 
63; 
Year the tank was designated as a leaking tank: 1977. 

Tank: TX-117; 
Year the tank was placed in service: 1947; 
Planned or actual retrieval of waste (as of 2011): 2034; 
Years past its design life that the tank is scheduled to hold waste: 
62; 
Year the tank was designated as a leaking tank: 1977. 

Tank: TX-118; 
Year the tank was placed in service: 1947; 
Planned or actual retrieval of waste (as of 2011): 2033; 
Years past its design life that the tank is scheduled to hold waste: 
61; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: BX-101; 
Year the tank was placed in service: 1948; 
Planned or actual retrieval of waste (as of 2011): 2030; 
Years past its design life that the tank is scheduled to hold waste: 
57; 
Year the tank was designated as a leaking tank: 1972. 

Tank: BX-102; 
Year the tank was placed in service: 1948; 
Planned or actual retrieval of waste (as of 2011): 2035; 
Years past its design life that the tank is scheduled to hold waste: 
62; 
Year the tank was designated as a leaking tank: 1971. 

Tank: BX-103; 
Year the tank was placed in service: 1948; 
Planned or actual retrieval of waste (as of 2011): 2024; 
Years past its design life that the tank is scheduled to hold waste: 
51; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: BX-104; 
Year the tank was placed in service: 1948; 
Planned or actual retrieval of waste (as of 2011): 2024; 
Years past its design life that the tank is scheduled to hold waste: 
51; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: BX-105; 
Year the tank was placed in service: 1948; 
Planned or actual retrieval of waste (as of 2011): 2028; 
Years past its design life that the tank is scheduled to hold waste: 
55; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: BX-106; 
Year the tank was placed in service: 1948; 
Planned or actual retrieval of waste (as of 2011): 2026; 
Years past its design life that the tank is scheduled to hold waste: 
53; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: BX-107; 
Year the tank was placed in service: 1948; 
Planned or actual retrieval of waste (as of 2011): 2031; 
Years past its design life that the tank is scheduled to hold waste: 
58; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: BX-108; 
Year the tank was placed in service: 1948; 
Planned or actual retrieval of waste (as of 2011): 2032; 
Years past its design life that the tank is scheduled to hold waste: 
59; 
Year the tank was designated as a leaking tank: 1974. 

Tank: BX-109; 
Year the tank was placed in service: 1948; 
Planned or actual retrieval of waste (as of 2011): 2028; 
Years past its design life that the tank is scheduled to hold waste: 
55; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: BX-110; 
Year the tank was placed in service: 1948; 
Planned or actual retrieval of waste (as of 2011): 2033; 
Years past its design life that the tank is scheduled to hold waste: 
60; 
Year the tank was designated as a leaking tank: 1976. 

Tank: BX-111; 
Year the tank was placed in service: 1948; 
Planned or actual retrieval of waste (as of 2011): 2032; 
Years past its design life that the tank is scheduled to hold waste: 
59; 
Year the tank was designated as a leaking tank: 1984. 

Tank: BX-112; 
Year the tank was placed in service: 1948; 
Planned or actual retrieval of waste (as of 2011): 2028; 
Years past its design life that the tank is scheduled to hold waste: 
55; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: BY-101; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2028; 
Years past its design life that the tank is scheduled to hold waste: 
53; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: BY-102; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2026; 
Years past its design life that the tank is scheduled to hold waste: 
51; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: BY-103; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2028; 
Years past its design life that the tank is scheduled to hold waste: 
53; 
Year the tank was designated as a leaking tank: 1973. 

Tank: BY-104; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2026; 
Years past its design life that the tank is scheduled to hold waste: 
51; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: BY-105; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2031; 
Years past its design life that the tank is scheduled to hold waste: 
56; 
Year the tank was designated as a leaking tank: 1984. 

Tank: BY-106; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2030; 
Years past its design life that the tank is scheduled to hold waste: 
55; 
Year the tank was designated as a leaking tank: 1984. 

Tank: BY-107; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2029; 
Years past its design life that the tank is scheduled to hold waste: 
54; 
Year the tank was designated as a leaking tank: 1984. 

Tank: BY-108; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2031; 
Years past its design life that the tank is scheduled to hold waste: 
56; 
Year the tank was designated as a leaking tank: 1972. 

Tank: BY-109; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2029; 
Years past its design life that the tank is scheduled to hold waste: 
54; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: BY-110; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2026; 
Years past its design life that the tank is scheduled to hold waste: 
51; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: BY-111; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2028; 
Years past its design life that the tank is scheduled to hold waste: 
53; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: BY-112; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2031; 
Years past its design life that the tank is scheduled to hold waste: 
56; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: S-101; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2027; 
Years past its design life that the tank is scheduled to hold waste: 
52; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: S-102; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2023; 
Years past its design life that the tank is scheduled to hold waste: 
48; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: S-103; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2026; 
Years past its design life that the tank is scheduled to hold waste: 
51; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: S-104; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2030; 
Years past its design life that the tank is scheduled to hold waste: 
55; 
Year the tank was designated as a leaking tank: 1968. 

Tank: S-105; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2023; 
Years past its design life that the tank is scheduled to hold waste: 
48; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: S-106; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2027; 
Years past its design life that the tank is scheduled to hold waste: 
52; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: S-107; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2026; 
Years past its design life that the tank is scheduled to hold waste: 
51; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: S-108; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2027; 
Years past its design life that the tank is scheduled to hold waste: 
52; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: S-109; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2026; 
Years past its design life that the tank is scheduled to hold waste: 
51; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: S-110; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2029; 
Years past its design life that the tank is scheduled to hold waste: 
54; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: S-111; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2028; 
Years past its design life that the tank is scheduled to hold waste: 
53; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: S-112; 
Year the tank was placed in service: 1950; 
Planned or actual retrieval of waste (as of 2011): 2007; 
Years past its design life that the tank is scheduled to hold waste: 
32; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: TY-101; 
Year the tank was placed in service: 1951; 
Planned or actual retrieval of waste (as of 2011): 2033; 
Years past its design life that the tank is scheduled to hold waste: 
57; 
Year the tank was designated as a leaking tank: 1973. 

Tank: TY-102; 
Year the tank was placed in service: 1951; 
Planned or actual retrieval of waste (as of 2011): 2031; 
Years past its design life that the tank is scheduled to hold waste: 
55; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: TY-103; 
Year the tank was placed in service: 1951; 
Planned or actual retrieval of waste (as of 2011): 2032; 
Years past its design life that the tank is scheduled to hold waste: 
56; 
Year the tank was designated as a leaking tank: 1973. 

Tank: TY-104; 
Year the tank was placed in service: 1951; 
Planned or actual retrieval of waste (as of 2011): 2032; 
Years past its design life that the tank is scheduled to hold waste: 
56; 
Year the tank was designated as a leaking tank: 1981. 

Tank: TY-105; 
Year the tank was placed in service: 1951; 
Planned or actual retrieval of waste (as of 2011): 2032; 
Years past its design life that the tank is scheduled to hold waste: 
56; 
Year the tank was designated as a leaking tank: 1960. 

Tank: TY-106; 
Year the tank was placed in service: 1951; 
Planned or actual retrieval of waste (as of 2011): 2031; 
Years past its design life that the tank is scheduled to hold waste: 
55; 
Year the tank was designated as a leaking tank: 1959. 

Tank: SX-101; 
Year the tank was placed in service: 1953; 
Planned or actual retrieval of waste (as of 2011): 2024; 
Years past its design life that the tank is scheduled to hold waste: 
46; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: SX-102; 
Year the tank was placed in service: 1953; 
Planned or actual retrieval of waste (as of 2011): 2027; 
Years past its design life that the tank is scheduled to hold waste: 
49; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: SX-103; 
Year the tank was placed in service: 1953; 
Planned or actual retrieval of waste (as of 2011): 2028; 
Years past its design life that the tank is scheduled to hold waste: 
50; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: SX-104; 
Year the tank was placed in service: 1953; 
Planned or actual retrieval of waste (as of 2011): 2030; 
Years past its design life that the tank is scheduled to hold waste: 
52; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: SX-105; 
Year the tank was placed in service: 1953; 
Planned or actual retrieval of waste (as of 2011): 2027; 
Years past its design life that the tank is scheduled to hold waste: 
49; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: SX-106; 
Year the tank was placed in service: 1953; 
Planned or actual retrieval of waste (as of 2011): 2026; 
Years past its design life that the tank is scheduled to hold waste: 
48; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: SX-107; 
Year the tank was placed in service: 1953; 
Planned or actual retrieval of waste (as of 2011): 2027; 
Years past its design life that the tank is scheduled to hold waste: 
49; 
Year the tank was designated as a leaking tank: 1964. 

Tank: SX-108; 
Year the tank was placed in service: 1953; 
Planned or actual retrieval of waste (as of 2011): 2030; 
Years past its design life that the tank is scheduled to hold waste: 
52; 
Year the tank was designated as a leaking tank: 1962. 

Tank: SX-109; 
Year the tank was placed in service: 1953; 
Planned or actual retrieval of waste (as of 2011): 2029; 
Years past its design life that the tank is scheduled to hold waste: 
51; 
Year the tank was designated as a leaking tank: 1965. 

Tank: SX-110; 
Year the tank was placed in service: 1953; 
Planned or actual retrieval of waste (as of 2011): 2030; 
Years past its design life that the tank is scheduled to hold waste: 
52; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: SX-111; 
Year the tank was placed in service: 1953; 
Planned or actual retrieval of waste (as of 2011): 2028; 
Years past its design life that the tank is scheduled to hold waste: 
50; 
Year the tank was designated as a leaking tank: 1974. 

Tank: SX-112; 
Year the tank was placed in service: 1953; 
Planned or actual retrieval of waste (as of 2011): 2027; 
Years past its design life that the tank is scheduled to hold waste: 
49; 
Year the tank was designated as a leaking tank: 1969. 

Tank: SX-113; 
Year the tank was placed in service: 1953; 
Planned or actual retrieval of waste (as of 2011): 2028; 
Years past its design life that the tank is scheduled to hold waste: 
50; 
Year the tank was designated as a leaking tank: 1962. 

Tank: SX-114; 
Year the tank was placed in service: 1953; 
Planned or actual retrieval of waste (as of 2011): 2026; 
Years past its design life that the tank is scheduled to hold waste: 
48; 
Year the tank was designated as a leaking tank: 1972. 

Tank: SX-115; 
Year the tank was placed in service: 1953; 
Planned or actual retrieval of waste (as of 2011): 2027; 
Years past its design life that the tank is scheduled to hold waste: 
49; 
Year the tank was designated as a leaking tank: 1965. 

Tank: A-101; 
Year the tank was placed in service: 1954; 
Planned or actual retrieval of waste (as of 2011): 2020; 
Years past its design life that the tank is scheduled to hold waste: 
41; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: A-102; 
Year the tank was placed in service: 1954; 
Planned or actual retrieval of waste (as of 2011): 2017; 
Years past its design life that the tank is scheduled to hold waste: 
38; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: A-103; 
Year the tank was placed in service: 1954; 
Planned or actual retrieval of waste (as of 2011): 2022; 
Years past its design life that the tank is scheduled to hold waste: 
43; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: A-104; 
Year the tank was placed in service: 1954; 
Planned or actual retrieval of waste (as of 2011): 2020; 
Years past its design life that the tank is scheduled to hold waste: 
41; 
Year the tank was designated as a leaking tank: 1975. 

Tank: A-105; 
Year the tank was placed in service: 1954; 
Planned or actual retrieval of waste (as of 2011): 2020; 
Years past its design life that the tank is scheduled to hold waste: 
41; 
Year the tank was designated as a leaking tank: 1963. 

Tank: A-106; 
Year the tank was placed in service: 1954; 
Planned or actual retrieval of waste (as of 2011): 2017; 
Years past its design life that the tank is scheduled to hold waste: 
38; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: AX-101; 
Year the tank was placed in service: 1965; 
Planned or actual retrieval of waste (as of 2011): 2018; 
Years past its design life that the tank is scheduled to hold waste: 
28; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: AX-102; 
Year the tank was placed in service: 1965; 
Planned or actual retrieval of waste (as of 2011): 2017; 
Years past its design life that the tank is scheduled to hold waste: 
27; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: AX-103; 
Year the tank was placed in service: 1965; 
Planned or actual retrieval of waste (as of 2011): 2016; 
Years past its design life that the tank is scheduled to hold waste: 
26; 
Year the tank was designated as a leaking tank: [Empty]. 

Tank: AX-104; 
Year the tank was placed in service: 1965; 
Planned or actual retrieval of waste (as of 2011): 2016; 
Years past its design life that the tank is scheduled to hold waste: 
26; 
Year the tank was designated as a leaking tank: [Empty]. 

Source: DOE. GAO-15-40. 

[A] Although the Department of Energy (DOE) had planned, in its 2011 
Office of River Protection System Plan (the source of the data), to 
retrieve the waste from these tanks by the dates indicated, the waste 
retrieval from these tanks is not yet completed. An update to this 
plan is scheduled to be released by DOE in the beginning of fiscal 
year 2015. 

[End of table] 

[End of section] 

Appendix IV: Comments from the Department of Energy: 

Department of Energy: 
Washington, DC 20585: 

November 7, 2014: 

Mr. David Trimble: 
Director: 
Natural Resources and Environment: 
U.S. Government Accountability Office: 
441 G Street, N.W. 
Washington, DC 20548: 

Dear Mr. Trimble: 

The Department of Energy (DOE) appreciates the opportunity to provide 
comments, including those related to the factual accuracy on the 
Government Accountability Office's (GAO) draft report; GAO-15-40, 
Hanford Cleanup: Condition of Tanks May Further Limit DOE's Ability to 
Respond to Leaks and Intrusions. The Department believes that the 
comments contained in the enclosed table clarify inaccuracies in the
draft report and importantly contribute to its overall quality. The 
recommendations provided in the draft report are well aligned with 
DOE's ongoing initiatives for management of the double-shell tanks 
(DSTs) and single-shell tanks (SSTs) at Hanford, and we accept the 
recommendations. 

DOE has an active DST/SST integrity program, and systematically 
assesses the condition of the DSTs and SSTs. This program includes the 
use of robotic ultrasonic devices, corrosion monitoring probes, and 
remote video cameras for the DSTs. In 20 12, these programs identified 
a leak in DST AY-102. To the extent that the cause of the leak can
be determined when DOE completes removal of the waste from this tank, 
that information will inform the assessments and maintenance of other 
DSTs. In the near term, the Office of River Protection (ORP) has 
further enhanced the DST inspection program that identified this leak 
and has convened an expert independent panel to further recommend 
additional improvements. 

DOE is also actively evaluating methods to create and is creating 
additional DST space. For example, since the last operation of the 242-
A Evaporator in 2010, substantial upgrades were made to increase its 
operational reliability. The 242-A Evaporator restarted in September, 
and has created over 7S0,000 gallons of space to date. This facility 
is planned to reduce waste volume in the DST system at an estimated 
rate of 1M gallons per year for the next 3 years. 

At the same time, DOE has also increased the operational limits in the 
DSTs (i.e., the levels at which waste can be safely stored). The 
operating capacity in four DSTs has already been increased, creating 
approximately 400,000 gallons of additional usable space. The waste 
level capacity in two tanks will be increased in fiscal year 2015 by a
total of 200,000 gallons. In addition to evaluating operational 
capacity with the DSTs, ORP will examine the extent to which future 
planned facilities will provide additional storage capacity. 

DOE is also systematically initiating actions to reduce the volume of 
the remaining waste in the SSTs through retrievals and the removal of 
surface liquids to further minimize the potential of leaks to the 
environment and the volume of waste that will be transferred to
the DSTs. For example, DOE plans to use an exhauster to further reduce 
surface liquids in the SSTs. The exhauster is in place at SST T-III 
and will begin reducing the remaining surface liquid in this tank in 
calendar year 2015. Once exhauster operations at this tank are 
complete, the exhauster will be used at other SSTs. 

DOE has made progress in the management of the tanks at Hanford. The 
mitigation of risks associated with managing this waste continues to 
be one of DOE's highest priorities for Hanford and the mission of the 
Office of Environmental Management. DOE appreciates GAO's recognition 
of its comprehensive management practices and addressing the enclosed 
comments in GAO's final report. 

If you have any questions, please contact me or Mr. Kenneth G. Picha, 
Jr., Deputy Assistant Secretary for Tank Waste and Nuclear Material, 
at (202)586-2003. 

Sincerely, 

Signed by: 

Mark Whitney: 
Acting Assistant Secretary for Environmental Management: 

Enclosure: 

[End of section] 

Appendix V: GAO Contact and Staff Acknowledgments: 

GAO Contact: 

David C. Trimble, (202) 512-3841 or trimbled@gao.gov: 

Staff Acknowledgments: 

In addition to the individual named above, Dan Feehan, Assistant 
Director; Mark Braza; John Delicath; Scott Fletcher; Rich Johnson; 
Jeff Larson; Armetha Liles; and Kyle Stetler made key contributions to 
this report. 

[End of section] 

Footnotes: 

[1] The WTP, as currently configured, is to consist of a pretreatment 
facility that separates waste into high-level and low-activity 
radioactivity waste streams; two facilities to treat these separated 
streams using a process called vitrification, where waste is mixed 
with melted glass and poured into steel canisters where it cools and 
hardens in preparation for its final disposal; an analytical 
laboratory; and a variety of supporting facilities. A portion of the 
low-activity waste will be treated using a supplemental treatment 
technology and facility yet to be selected by DOE. 

[2] GAO, Hanford Waste Treatment Plant: DOE Needs to Take Action to 
Resolve Technical and Management Challenges, [hyperlink, 
http://www.gao.gov/products/GAO-13-38] (Washington, D.C.: Dec. 19, 
2012) 

[3] This request was originally made by the Chairman of the Senate 
Committee on Energy and Natural Resources, Senator Ron Wyden, who is 
now a member of the Senate. 

[4] In October 2010, the U.S. District Court in Spokane approved and 
entered a judicial consent decree that imposes a schedule for 
constructing and beginning operation of the WTP to treat waste from 
Hanford's underground tanks. 

[5] Roy E. Gephart, Hanford: A Conversation about Nuclear Waste and 
Cleanup (Columbus, Ohio: Battelle Press, 2003). 

[6] According to DOE documents, one SST (tank S-102) presented unique 
pumping challenges and did not fully meet the interim stabilization 
criteria until 2010. Ecology sued DOE to compel the completion of 
interim stabilization in 1999, leading to a consent decree, which 
resulted in completion of the interim stabilization program under the 
consent decree and the ultimate termination of that decree in 2011. 

[7] According to Ecology officials, there were a number of tanks that 
either experienced equipment failure or were not reasonably assessable 
and therefore have liquids remaining in the tanks that exceeded these 
numerical criteria. 

[8] The TPA lays out a series of legally enforceable milestones for 
completing major activities in Hanford's waste treatment and cleanup 
process. The purpose of the TPA is to ensure that Hanford cleanup 
activities comply with the Comprehensive Environmental Response, 
Compensation, and Liability Act (CERCLA), Resource Conservation and 
Recovery Act (RCRA), and Washington's Hazardous Waste Management Act. 
DOE entered into the TPA pursuant to CERCLA, Executive Order 12580, 
and the Atomic Energy Act of 1954. 

[9] See GAO, NUCLEAR WASTE: DOE Lacks Critical Information Needed to 
Assess Its Tank Management Strategy at Hanford, [hyperlink, 
http://www.gao.gov/products/GAO-08-793] (Washington, D.C.: June 30, 
2008). 

[10] RCRA defines "mixed waste" to mean waste that contains both 
hazardous waste and source, special nuclear, or by-product material 
subject to the Atomic Energy Act of 1954. 42 U.S.C. § 6903(41). The 
term "solid waste" does not include source, special nuclear or by-
product material. 42 U.S.C. § 6903(27). 

[11] Under the applicable state regulations, the assessment must be 
conducted by an independent, qualified registered professional 
engineer. 

[12] These modified procedures are found in RPP-9937 Rev. 3E Single 
Shell Tank System Leak Detection and Monitoring Functions and 
Requirements Document, 2014. 

[13] Initially issued in 2002, the System Plan is a long-term cleanup 
strategy document that DOE is required under the TPA to update every 3 
years. According to DOE officials, DOE is planning to issue an update 
to the System Plan in October 2014. 

[14] This tank was initially assumed to be leaking in 1979 and, based 
on continued observations of decreasing levels of liquid in the tank, 
DOE confirmed this assessment in 1994. In 1995, DOE completed the 
interim stabilization process for T-111. 

[15] DOE and Ecology are currently negotiating revisions to the SST 
management requirements as part of the process under way to revise 
Hanford's sitewide RCRA hazardous waste management permit. RCRA 
prohibits the treatment, storage, or disposal of hazardous waste 
without a permit. 

[16] RPP-ASMT-53793, Tank 241-AY-102 Leak Assessment Report (October 
2012). 

[17] According to DOE officials, factors other than a leak, such as 
evaporation of liquids in the waste, can cause waste levels to 
decrease slightly. 

[18] A DOE official said that the previous inspection methodology did 
not attempt to inspect the entire annulus space. Prior inspections 
looked for changes in the general conditions, and areas of interest 
from previous inspections were tracked. Prior inspections viewed as 
much as possible through one riser in each of the four quadrants of a 
DST, which typically covered about 40 percent of the annulus. 

[19] The agreement also requires, among other things, that DOE submit 
a revised monitoring plan for annulus inspection, waste temperature 
monitoring, and annulus ventilation monitoring, and establishes 
monetary penalties for DOE's failure to meet the agreement's deadlines. 

[20] Under RCRA, the SSTs may not be used indefinitely for waste 
storage. In its 2012 tank waste management environmental impact 
statement, DOE stated that it did not consider in detail the option of 
using the SSTs to temporarily store waste, in part because the SSTs 
have been declared unfit for use and cannot readily be made compliant 
with current regulations. The EIS noted that Ecology has established 
several conditions for considering SSTs for staging, including SST 
system upgrades and agreement on selection criteria for the tanks to 
be used. DOE noted that these criteria had not been developed. 

[21] Prior to restarting the evaporator, in June 2014, officials from 
the Safety Board raised concerns about the safety of restarting this 
facility. DOE responded to these concerns in August 2014 to the 
satisfaction of the Safety Board. 

[22] Conversely, however, under the modified requirements SSTs that 
meet the interim stabilization criteria do not require leak response. 

[23] We currently have an ongoing review of DOE's proposal to build 
these new treatment facilities. 

[24] The 2010 consent decree called for 10 SSTs in the C Farm to be 
emptied by September 30, 2014. As of the writing of this report, only 
5 of those 10 SSTs had been emptied. In response to this and other 
missed milestones in the 2010 consent decree, Ecology petitioned the 
court to amend the consent decree with DOE in October 2014. 

[25] In 2001, DOE established a DST Integrity Program to implement 
controls and inspections to ensure that the DSTs will be available for 
use through the end of the cleanup mission. 

[26] An EIS must, among other things, (1) describe the environment 
that will be affected, (2) identify alternatives to the proposed 
action and identify the agency's preferred alternative, (3) present 
the environmental impacts of the proposed action and alternatives, and 
(4) identify any adverse environmental impacts that cannot be avoided 
should the proposed action be implemented. 

[End of section] 

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