[Federal Register Volume 66, Number 64 (Tuesday, April 3, 2001)]
[Notices]
[Pages 17689-17692]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-8064]


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DEFENSE NUCLEAR FACILITIES SAFETY BOARD

[Recommendation 2001-1]


High-Level Waste Management at the Savannah River Site

AGENCY: Defense Nuclear Facilities Safety Board.

ACTION: Notice, recommendation.

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SUMMARY: The Defense Nuclear Facilities Safety Board has made a 
recommendation to the Secretary of Energy pursuant to 42 U.S.C. 
2286a(a)(5) concerning high-level waste management at the Savannah 
River Site.

DATES: Comments, data, views, or arguments concerning this 
recommendation are due on or before May 3, 2001.

ADDRESSES: Send comments, data, views, or arguments concerning this 
recommendation to: Defense Nuclear Facilities Safety Board, 625 Indiana 
Avenue, NW., Suite 700, Washington, DC 20004-2901.

FOR FURTHER INFORMATION CONTACT: Kenneth M. Pusateri or Andrew L. 
Thibadeau at the address above or telephone (202) 694-7000.

    Dated: March 27, 2001.
John T. Conway,
Chairman.

[Recommendation 2001-1],

High-Level Waste Management at the Savannah River Site

Dated: March 23, 2001.
    The mission of the Savannah River Site (SRS) high-level waste (HLW) 
system is to safely store and treat HLW while also supporting site 
initiatives such as the stabilization of remnants of nuclear weapons 
production. Storage of HLW is provided by 49 tanks, referred to 
collectively as the Tank Farms, which contain approximately 34 million 
gallons of HLW. Presently, treatment primarily consists of waste 
concentration in evaporators and sludge vitrification at the Defense 
Waste Processing Facility (DWPF). DWPF currently produces more than 225 
vitrified waste canisters per year and during its lifetime is expected 
to produce a total of approximately 6,000 canisters. Recently, the most 
pressing challenge at the SRS Tank Farms has been managing available 
tank space.
    Average annual waste inflow to the Tank Farms totals approximately 
2.5 million gallons, generated primarily from vitrification activities 
and nuclear material stabilization. The largest portion of the inflow, 
approximately 1.3 million gallons, is the DWPF return

[[Page 17690]]

waste stream (DWPF recycle). Another 500,000 gallons consists of sludge 
wash water, generated during the preparation of sludge feed to DWPF. 
Nuclear material stabilization operations at the chemical processing 
canyons generate approximately 600,000 gallons of annual inflow, and 
another 100,000 gallons is generated through several miscellaneous 
operations.
    Reducing the volume of waste in the Tank Farms is currently 
accomplished primarily by concentrating dilute waste through 
evaporation. The operation of all three Tank Farm evaporators can 
reduce the required storage volume by more than 2.5 million gallons 
annually. However, the evaporators have recently experienced 
significant problems, limiting the two newest and highest-capacity 
evaporators to little or no operation. The vitrification of sludge at 
DWPF does not reduce the volume of waste in the Tank Farms because the 
volume of DWPF recycle and sludge wash water returned to the Tank Farms 
is significantly greater than the volume of sludge removed. The lack of 
adequate volume reduction, combined with the waste produced during 
vitrification operations, has led to a situation in which available 
tank space has steadily decreased.
    Contributing to the tank space problem is an emphasis on the 
operation of the DWPF at the expense of the overall operability of the 
Tank Farms. This situation is evident in the HLW Performance-Based 
Incentives in the contract, which are weighted more than 60 percent 
toward the production of vitrified waste canisters. Tank space has now 
been reduced to a critically low level, which threatens to halt DWPF 
vitrification.
    Several options have been identified at SRS which could help 
alleviate the tank space shortage. These include operation of a salt 
processing facility, reduction or elimination of the DWPF recycle 
stream, recovery of former In-Tank Precipitation (ITP) Facility process 
tanks for HLW operation, and solution of problems that have 
significantly limited evaporator operation. These options are discussed 
in more detail below.

Salt Processing

    An essential element missing from the current HLW treatment 
operations is salt processing. Salt processing would remove key 
radionuclides from HLW liquids and saltcake, allowing the remaining 
large volumes of water and soluble salts to be disposed of as low-level 
waste. The design, construction, and operation of a salt processing 
facility would be required to solve the tank space problems at the Tank 
Farms. Originally, the contractor attempted to backfit a salt 
processing capability into three HLW tanks that became the ITP 
Facility. Conceived as a cost-effective approach toward salt 
processing, the project was suspended in early 1998 because of safety 
and operability issues.
    Recognizing the urgency of continuing salt processing development, 
the contractor aggressively examined alternatives and, in 1999, 
recommended pursuing a modified precipitation process. DOE chose to 
delay a decision on this recommendation and directed the contractor to 
study the problem further. Now, more than 3 years after the 
cancellation of ITP, there is still no decision on the basic technology 
to be used for salt processing. The salt processing facility is 
currently delayed until at least 2010. The most recent milestone for 
this program, issuance of a draft request for proposals to design and 
build the facility, has been overdue since December 2000, primarily 
because of funding priorities.

DWPF Recycle

    Currently, DWPF produces the largest volume of waste received at 
the Tank Farms. The combination of the waste generated within DWPF and 
the large volume of water and corrosion inhibitor added to make the 
waste acceptable for tank storage produces more than 1 million gallons 
of DWPF recycle each year. The contractor has long recognized that very 
large volumes of waste were being sent from DWPF to the Tank Farms, and 
many planning documents suggest that an evaporator could be installed 
at DWPF to nearly eliminate the recycle stream. However, DOE has never 
pursued this activity.
    In 1999, a contractor system engineering team again recommended 
that an evaporator be used to eliminate DWPF recycle, but also 
requested that DWPF staff consider other means of reducing the recycle 
volume. Through modification to the facility, the DWPF staff found ways 
to reduce the recycle volume from more than 2 million gallons per year 
to the present level of approximately 1.3 million gallons per year.
    This great volume savings notwithstanding, the DWPF recycle 
continues to place a significant strain on the HLW system. DWPF recycle 
generates the largest volume of waste receipts, and silicates contained 
in the recycle have been found to cause significant problems with the 
evaporators.

Former ITP Process Tanks

    Approximately 3 million gallons of tank space could be added by 
returning Tanks 48, 49, and 50 from the former ITP Facility to HLW 
service. During the development of the ITP process, these modern, fully 
compliant tanks were dedicated exclusively to ITP service. The 
contractor has planned to recover Tanks 49 and 50 for some time, but 
progress has been slow. The contractor is working to return Tank 49 to 
HLW service this year. However, restoration of Tank 50 is not being 
aggressively pursued, and the tank is not scheduled to be available 
until the end of 2002. There are currently no plans for near-term 
recovery of Tank 48, which contains tetraphenylborate precipitates 
generated during ITP process testing. Although recovery of Tank 48 
poses significant technical issues, restoration of Tank 50 is limited 
primarily by the resources applied to the effort.

Evaporator Operation

    The three HLW evaporators (2F, 2H, and 3H) have the combined 
capacity to recover more than 2.5 million gallons of tank space per 
year and are needed to provide sufficient tank space to support Tank 
Farm operation until a salt processing facility becomes operational. 
However, the actual productivity of the evaporators has been severely 
limited by waste compatibility issues and degradation of equipment.
    Waste Compatibility Issues--In late 1999, the contractor discovered 
unexpected solids accumulating in the 2H evaporator pot. These solids 
are believed to be generated by silicates in DWPF recycle reacting with 
aluminum in canyon wastes. The deposits contain enriched uranium and 
present a potential criticality hazard. The 2H evaporator has been shut 
down since January 2000 while this issue is being resolved.
    The contractor is working to remove these deposits and restart the 
2H evaporator by July 2001. In the meantime, DWPF recycle waste, as 
well as other wastes high in silicon content, are prohibited from the 
2F and 3H evaporator systems until the mechanism of the deposition has 
been understood and a solution devised.
    Tritium is found in many of the HLW tanks and continues to enter 
the Tank Farms as the result of spent nuclear fuel processing at the 
SRS canyon facilities. The concentration of tritium varies from tank to 
tank. Tritium passes through the system during HLW pretreatment and 
evaporation, eventually being released at the Effluent Treatment 
Facility. Evaporator operations are limited on

[[Page 17691]]

occasion by the need to coordinate Tank Farm activities and monitor the 
tritium levels to prevent the release of tritium from the system in 
excess of release limits. Like the silicate problem, the need to 
segregate tritiated waste streams adversely affects the ability to use 
tank space efficiently.
    Equipment Issues--Several emergent equipment issues have also 
limited the ability of evaporators to concentrate waste. In 1999 and 
2000, startup of the 3H evaporator was delayed for months because of 
problems with a valve in the system. In November 2000, the contractor 
discovered that all five of the cooling coils for the tank that 
receives concentrate from this evaporator were leaking. Because of 
temperature limits in this tank, the 3H evaporator, which is the newest 
and highest-capacity evaporator, is now limited to only a few days of 
operation each month.
    Because of the problems with the 2H and 3H evaporators, operation 
of the 2F evaporator is now providing most of the space gains for the 
HLW system. The 2F evaporator pot has been in service for more than 10 
years and has exceeded its designed service life. Failure of this pot 
would further reduce the ability to regain space in the Tank Farms. 
Additionally, the contractor's plan for handling space issues during 
the next few years relies heavily on the ability to perform many inter-
area transfers (i.e., between F- and H-Areas). Significant failures of 
equipment or systems associated with the inter-area transfer system 
would also impact the Tank Farm system.
    Many of the significant equipment issues identified with the Tank 
Farms were unexpected. However, given the age of the HLW system at SRS, 
it is likely that additional significant issues will be identified in 
future years.

High-Level Waste Tank 6

    In late 2000, the contractor evaluated various short-term 
alternatives for addressing the lack of tank space threatening to shut 
down DWPF operations. The alternative chosen started with a transfer of 
330,000 gallons of DWPF recycle to Tank 6, a 1950s-vintage Type I tank. 
Although 5 of the 12 original Type I tanks had already leaked, the 
prior service of Tank 6 and primary tank wall inspections indicated 
that the tank was sound. Before the transfer to Tank 6, the contractor 
made preparations to pump liquid from the tank annulus back into the 
primary tank in the event of a large leak. In January 2001, shortly 
after the transfer to Tank 6, the contractor discovered approximately 
90 gallons of liquid in the tank annulus and, upon further video 
inspection, found 6 leak sites on the primary tank wall.
    After the primary tank wall, the next barrier to the release of 
waste is the 5-foot-tall annulus pan in which the primary tank sits. 
The annulus pan was not designed for the long-term storage of waste and 
cannot be adequately inspected. Therefore, the condition of the pan is 
not well known, and it cannot be relied upon as a long-term containment 
for liquid waste. If the annulus were to leak waste to the environment, 
it would likely take several years to detect the leak through the use 
of external monitoring wells.
    DOE and the contractor have thus far proposed transferring only 
that portion of waste in Tank 6 above the three highest, most visibly 
active, leak sites. The waste level would remain above the other three 
leak sites. DOE and the contractor prefer this course of action because 
it would have the least impact on the operation of DWPF, in that it 
would minimize waste transfers from Tank 6 into tanks that would 
otherwise receive DWPF recycle or sludge wash water. However, this 
course of action represents a reduction in the margin of safety in the 
containment of liquid HLW. Furthermore, because of the elevated tritium 
content in the waste, the contractor plans to continue storage in Tank 
6, and avoid transfers to other tanks and evaporators until additional 
space becomes available in Tank 8 in approximately two years.
    The use of Tank 6 to alleviate pressing storage problems is an 
example of the need to fall back on doubtful engineering solutions for 
short-term mitigation of problems at SRS. Lack of sound engineering 
inevitably narrows desirable options.

Recommendation

    In the Board's view, DOE has not proceeded with due diligence to 
address the worsening condition of the SRS Tank Farms. Continued delays 
in achieving long-term solutions increase the pressure to accept 
conditions that reduce the safety margin and increase operational 
complexity. The continuing reliance on old HLW tanks whose design would 
be unacceptable today, on support systems that have exceeded their 
design life, and on tanks known to have numerous cracks, has been 
required to manage the Tank Farms and to make partial progress toward 
the ultimate goal of immobilization of HLW. However, the Board is not 
convinced that continued storage of readily removable HLW liquid above 
known leak sites is necessary to achieve this goal. Accordingly, the 
Board recommends the following actions:
    1. Initiate actions to remove transferable HLW liquid from Tank 6 
to a level below all known leak sites.
    2. Reassess the schedule and priority for selecting a technology 
for a salt processing capability, and vigorously accelerate the 
schedule leading to operation of a salt processing facility.
    3. Develop and implement an integrated plan for HLW tank space 
management that emphasizes continued safe operation of the Tank Farms 
throughout its life cycle. This plan should include enough margin to 
accommodate contingencies and reduce overall programmatic risk. The 
plan should also restore operating margin to the Tank Farms by 
including action to:
    a. reduce or eliminate the DWPF recycle stream,
    b. recover former ITP tanks for Tank Farm operations,
    c. assess the desirability of adding an additional HLW evaporator 
to support Tank Farm operations,
    d. assess the feasibility of constructing new HLW tanks, and
    e. resolve waste compatibility and equipment degradation problems 
to allow unconstrained operation of the three existing evaporators.
    4. Reassess contractor incentives to ensure that near-term 
production at DWPF is not overemphasized at the expense of safety 
margin in the Tank Farms.
    Actions provided by this recommendation are known to the contractor 
and DOE. In fact, all of these actions either have been or are being 
pursued to some degree. However, the unfocused manner in which they are 
being pursued is evident in the continued year-to-year delays. 
Meanwhile, problems caused by these delays are being resolved in part 
through reductions in margins of safety.
    Given the time-sensitive nature of the actions identified by this 
Recommendation, the Board suggests that the Secretary of Energy avail 
himself of the authority under the Atomic Energy Act to ``implement any 
such Recommendation (or part of any such Recommendation) before, on, or 
after the date on which the Secretary of Energy transmits the 
implementation plan to the Board under this subsection.'' See 42 U.S.C. 
2286d(e).

John T. Conway,
Chairman.

Appendix--Transmittal Letter to the Secretary of Energy

March 23, 2001.
The Honorable Spencer Abraham,
Secretary of Energy, 1000 Independence Avenue, SW., Washington, DC 
20585-1000.


[[Page 17692]]


    Dear Secretary Abraham: The Defense Nuclear Facilities Safety 
Board (Board) has been following closely the Department of Energy's 
(DOE) response to recently discovered leaks in Tank 6, a high-level 
waste (HLW) storage tank at the Savannah River Site (SRS). While 
this issue must be addressed on a specific basis, it is only a 
symptom of a much larger problem--the critical shortage of tank 
space in the HLW system--that threatens to delay stabilization of 
nuclear materials at SRS and may result in suspending vitrification 
of HLW at the Defense Waste Processing Facility (DWPF). Furthermore, 
this problem has led to a reduced margin of safety and a short-
sighted emphasis on solving immediate problems at the expense of 
investing in comprehensive efforts to enhance the safety and 
flexibility of the HLW system.
    As a result, the Board, on March 23, 2001, unanimously approved 
Recommendation 2001-1, High-Level Waste Management at the Savannah 
River Site, which is enclosed for your consideration. After your 
receipt of this recommendation and as required by 42 U.S.C. 
2286d(a), the Board will promptly make it available to the public in 
DOE's regional public reading rooms. The Board has confirmed with 
DOE that the recommendation contains no information that is 
classified or otherwise restricted. Providing this recommendation 
does not include information restricted by DOE under the Atomic 
Energy Act of 1954, 42 U.S.C. 2161-68, as amended, please arrange to 
have it promptly placed on file in your regional public reading 
rooms. The Board will also publish this recommendation in the 
Federal Register.
        Sincerely,

John T. Conway,
Chairman.
[FR Doc. 01-8064 Filed 4-2-01; 8:45 am]
BILLING CODE 3670-01-U