[Federal Register Volume 67, Number 160 (Monday, August 19, 2002)]
[Notices]
[Pages 53784-53787]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-20968]


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DEPARTMENT OF ENERGY


Savannah River Site High-Level Waste Tank Closure

AGENCY: Department of Energy (DOE).

ACTION: Record of decision.

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SUMMARY: In the Savannah River Site (SRS) High-Level Waste Tank Closure 
Environmental Impact Statement (Tank Closure EIS, DOE/EIS-0303) DOE 
considered alternatives for closure of 49 high-level radioactive waste 
(HLW) tanks and associated equipment such as evaporator systems, 
transfer pipelines, diversion boxes, and pump pits. DOE needs to close 
these tanks to reduce human health and safety risks at and near the HLW 
tanks, and to reduce the eventual introduction of contaminants into the 
environment. Moreover, DOE must comply with the provisions of the 
Wastewater Systems Operating Permit issued by the South Carolina 
Department of Health and Environmental Control (SCDHEC) for HLW tank 
operations, and with the closure schedule and provisions contained in 
the Industrial Wastewater Closure Plan for F- and H-Area High-Level 
Waste Tank Systems (the General Closure Plan) approved by SCDHEC. DOE 
evaluated three alternatives for closure of the tank systems: Stabilize 
Tanks, Clean and Remove Tanks, and No Action. The Stabilize Tanks 
alternative has three options--Fill with Grout (preferred alternative), 
Fill with Sand, and Fill with Saltstone.
    DOE has selected the preferred alternative identified in the Final 
EIS, Stabilize Tanks--Fill with Grout, to guide development and 
implementation of closure of the high-level waste tanks and associated 
equipment at the SRS. Following bulk waste removal, DOE will clean the 
tanks if associated equipment at the SRS. Following bulk waste removal, 
DOE will clean the tanks if necessary to meet the performance 
objectives contained in the General Closure Plan and the tank-specific 
Closure Module, and then fill the tanks with grout.
    In parallel with tank closures, DOE will evaluate and consult with 
SCDHEC on closure methods and regulatory compliance revisions that will 
allow accelerated closure and reduction of risk associated with the HLW 
tanks. DOE remains committed to closure of the HLW tanks in accordance 
with the approved General Closure Plan.

ADDRESSES: Copies of the Tank Closure EIS and this Record of Decision 
may be obtained by calling a toll-free number (800-881-7292), by 
sending an e-mail request to [email protected], or by mailing a request to: 
Andrew Grainger, National Environmental Policy Act (NEPA) Compliance 
Officer, Savannah River Operations Office, Department of Energy, 
Building 742A, Room 185, Aiken, SC 29808. This Record of Decision will 
be available on the Department of Energy NEPA Web site, tis.eh.doe.gov/nepa/whatsnew.htm.

FOR FURTHER INFORMATION CONTACT: Questions concerning the SRS tank 
closure program can be submitted by calling 800-881-7292, mailing them 
to Mr. Andrew Grainger at the above address, or sending them 
electronically to the Savannah River Operations Office e-mail address, 
[email protected].
    For general information on the DOE NEPA process, please contact: 
Carol M. Borgstrom, Director, Office of NEPA Policy and Compliance, 
U.S. Department of Energy, 1000 Independence Avenue, SW., Washington, 
DC 20585, 202-586-4600 or leave a message at 800-472-2756.

SUPPLEMENTARY INFORMATION:

Background

    Nuclear materials production at the SRS resulted in the generation 
of large quantities of HLW that is stored onsite in large underground 
tanks. The HLW resulted from the dissolution of spent reactor fuel and 
nuclear targets to recover the valuable radioactive isotopes. DOE has 
stored the HLW in 51 large underground storage tanks located in the F- 
and H-Area Tank Farms at SRS. DOE has emptied and closed two of those 
tanks. Approximately 37 million gallons of HLW is stored in the 
remaining 49 HLW tanks.
    The HLW tank systems at SRS are operated under the authority of the 
Atomic Energy Act of 1954 (AEA) and DOE Orders issued pursuant to the 
AEA. The HLW tank systems also are operated in accordance with a permit 
issued by SCDHEC under the authority of the South Carolina Pollution 
Control Act for industrial wastewater treatment facilities. DOE is 
required to close the tank systems in accordance with AEA requirements 
and South Carolina Regulation R.61-82, ``Proper Closeout of Wastewater 
Treatment Facilities.'' This regulation requires that closures be 
carried out according to site-specific guidelines established by SCDHEC 
to prevent health hazards and to promote safety in and around the tank 
systems.

[[Page 53785]]

DOE has adopted a general strategy for HLW tank system closure, set 
forth in DOE's Industrial Wastewater Closure Plan for the F- and H-Area 
High-Level Waste Tank Systems (March 2000), known as the General 
Closure Plan.\1\ The General Closure Plan has been approved by SCDHEC 
and DOE must gain SCDHEC's approval on any revisions to the General 
Closure Plan. Also, DOE has entered into an agreement, the SRS Federal 
Facility Agreement, with the U.S. Environmental Protection Agency (EPA) 
and SCDHEC to remove from service and close 24 HLW tanks that do not 
meet Resource Conservation and Recovery Act secondary containment 
requirements. The remaining 27 tanks will also be closed when they are 
no longer required for service. Closure of the HLW tanks will comply 
with DOE's responsibilities under the AEA and the General Closure Plan, 
and be carried out under a schedule agreed to by DOE, EPA, and SCDHEC.
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    \1\ Although the Final Environmental Impact Statement reflected 
the 2000 Closure Plan, the Statement incorrectly cited the 1996 
Closure Plan.
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    The General Closure Plan identifies the resources (e.g., 
groundwater, air) potentially affected by contaminants remaining in the 
tanks after waste removal and closure; describes how the tanks will be 
cleaned and how the tank systems and residual wastes will be 
stabilized; and identifies Federal and State regulations and guidance 
that apply to the closures. The Plan describes the use of fate and 
transport models to calculate potential environmental exposure 
concentrations or radiological dose rates from the residual waste left 
in the tank systems. The General Closure Plan describes the method DOE 
will use to make sure the impacts of closure of individual tank systems 
do not exceed the environmental standards that apply to the entire F- 
and H-Area Tank Farms.
    Several issues related to the HLW tank closure program will be 
resolved as DOE implements this Record of Decision. These issues will 
be addressed during tank-by-tank closure and include: (1) Performance 
objectives for each tank that allow the cumulative closure to meet the 
overall performance standard; (2) the regulatory status of residual 
waste in the tanks, through a determination whether they are ``waste 
incidental to reprocessing;'' and (3) use of cleaning methods such as 
spray water washing or oxalic acid cleaning, if needed to meet tank-
specific performance objectives.

Performance Objectives

    In implementing this Record of Decision, DOE will establish 
performance objectives for closure of each HLW tank. Each performance 
objective will correspond to an overall performance standard identified 
in the General Closure Plan and will ensure that the overall 
performance standard can be met. For example, if the performance 
standard for drinking water in the receiving stream is 4 millirem per 
year, the combined contribution from contaminants from all tanks will 
not exceed the 4 millirem-per-year limit. DOE will evaluate closure for 
specific tanks to determine whether use of a specific closure option 
will allow DOE to meet the overall performance standard. Based on this 
analysis, DOE will develop a Closure Module (a tank-specific closure 
plan) for each HLW tank such that the performance objectives for the 
tank can be met. The Closure Module must be approved by SCDHEC before 
tank closure can begin.

Waste Incidental to Reprocessing

    Before bulk waste removal, the content of the tanks is HLW. The 
goal of the bulk waste removal and, if needed, subsequent cleaning of 
the tanks, is to meet DOE's criteria for Waste Incidental to 
Reprocessing. DOE Manual 435.1-1, which implements DOE Order 435.1, 
Radioactive Waste Management, describes two processes, citation and 
evaluation, for determining that HLW can be considered ``waste 
incidental to reprocessing'' and can therefore be managed under DOE's 
regulatory authority in accordance with requirements for transuranic 
waste or low-level waste. In implementing this Record of Decision, DOE 
will perform a waste incidental to reprocessing determination by 
evaluation on each HLW tank as part of the analysis used to prepare the 
Closure Module.

HLW Tank Cleaning

    Following bulk waste removal, DOE will clean the tanks, if 
necessary, to meet the performance objectives contained in the General 
Closure Plan and in the tank-specific Closure Module, which includes 
DOE's criteria for Waste Incidental to Reprocessing. In accordance with 
the General Closure Plan, the need for and the extent of any tank 
cleaning will be determined based on the analysis presented in the 
tank-specific Closure Module.
    If necessary tank cleaning by spray water washing will initially be 
performed. If performance objectives could not be met using spray water 
washing, other cleaning techniques would be employed. These techniques 
include mechanical methods, oxalic acid cleaning, or other chemical 
cleaning methods. Potential criticality safety concerns and 
interference with downstream waste processing activities such as 
Defense Waste Processing Facility glass quality could arise with the 
use of chemical cleaning methods and would have to be addressed.

Alternatives Considered

    In the EIS DOE evaluated three alternatives for tank closure, each 
of which begins when bulk waste removal from the tank has been 
completed. Under each alternative except No Action, DOE would close 49 
HLW tanks and associated waste handling equipment including 
evaporators, pumps, diversion boxes, and transfer lines.

Stabilize Tanks Alternative

    Following bulk waste removal and any required cleaning, DOE would 
fill the tanks with a material that would bind up remaining residual 
waste and prevent future collapse of the tanks. In the EIS DOE 
considered three options for tank stabilization under this alternative: 
Fill with Grout (preferred alternative), Fill with Sand, and Fill with 
Saltstone. Each tank system or group of tank systems would be evaluated 
to determine the inventory of radiological and nonradiological 
contaminants remaining after bulk waste removal. This information would 
be used to conduct a performance evaluation as part of the preparation 
of a Closure Module. In the evaluation DOE would consider (1) the types 
of contamination in the tank and the configuration of the tank system, 
and (2) the hydrogeologic conditions at and near the tank location, 
such as distance from the water table and distance to nearby streams. 
The performance evaluation would include modeling the projected 
contamination pathways for selected closure methods, and comparing the 
modeling results with the performance objectives developed in the 
General Closure Plan. If the modeling shows that performance objectives 
would be met, the Closure Module would be submitted to SCDHEC for 
approval. If the modeling shows that the performance objectives would 
not be met, then tank cleaning steps would be taken until sufficient 
waste had been removed that the objectives could be met. Therefore the 
closure configuration for each tank or group of tanks would be 
determined on a case-by-case basis through development of the Closure 
Module.

[[Page 53786]]

    Following approval of a Closure Module by SCDHEC, the tank 
stabilization process would begin. DOE's preferred option is to use 
grout, a concrete-like material, as backfill. The fill material would 
be high enough in pH to be compatible with the carbon steel walls of 
the tank. The grout would be formulated with chemical properties that 
would retard the movement of radionuclides in the residual waste in the 
closed tank. The grout would be poured in three distinct layers. The 
bottom-most layer would be specially formulated reducing grout to 
retard the migration of important contaminants. The middle layer would 
be a low-strength material designed to fill most of the volume of the 
tank interior. The final layer would be a high-strength grout to deter 
inadvertent intrusion from drilling. DOE is also considering an all-in-
one grout that would provide the same performance as the three separate 
layers of grout. If this all-in-one grout would provide the same 
performance and protection at a lesser cost, DOE would use it.
    Other fill options that DOE considered in the EIS are sand and 
saltstone. For these options, all other aspects of the closure process, 
including the determination that performance objectives could be met 
and approval of the Closure Module by SCDHEC, would be the same as 
described for the Fill with Grout option. Sand is readily available and 
inexpensive. However, it would be more difficult to completely fill 
void spaces with sand than with grout, and sand could not be formulated 
to retard the migration of radionuclides. Expected contamination levels 
in groundwater and surface water resulting from migration of residual 
contaminants would be higher than the levels for the preferred option. 
Saltstone, which is the low-radioactivity fraction of HLW mixed with 
cement, flyash, and slag, could also be used as fill material. 
Saltstone is normally disposed of as low-level waste in the SRS 
Saltstone Disposal Facility. This alternative would have the advantage 
of reducing the amount of Saltstone Disposal Facility area that would 
be required. Filling the tank with a grout mixture that is contaminated 
with radionuclides, like saltstone, would considerably complicate the 
project and increase worker radiation exposure. In addition, the 
saltstone would contain large quantities of nitrate that would not be 
present in the tank residual waste. Because nitrates are very mobile in 
the environment, these large quantities of nitrate would adversely 
impact the groundwater near the tank farms over the long term.
    Following the use of any of the stabilization options, four tanks 
in F-Area and four tanks in H-Area would require backfill soil to be 
placed over the top of the tanks to bring the ground surface at these 
tanks up to the surrounding surface elevation. The action would prevent 
ponding conditions that could accelerate degradation of the tank 
structure.

Clean and Remove Tanks Alternative

    The Clean and Remove Tanks alternative would involve cleaning the 
tanks, cutting them up in situ, removing them from the ground, and 
transporting tank components for disposal in an engineered disposal 
facility at another location on the SRS. For this alternative DOE would 
have to clean the tanks until they were clean enough to be safely 
removed and could meet waste acceptance criteria at SRS low-level waste 
disposal facilities. Cleaning techniques such as oxalic acid cleaning, 
mechanical cleaning and additional steps as yet undefined might be 
required. Worker exposure would have to be As Low As Reasonably 
Achievable to ensure protection of the individual workers required to 
perform the tank removal operations.
    Following bulk waste removal and tank cleaning, the steel 
components of the tank would be cut up, removed, placed in radioactive 
waste transport containers, (approximately 3,900 SRS low-level waste 
disposal boxes per tank), and transported to SRS radioactive waste 
disposal facilities for disposal. This alternative would require the 
construction of approximately 16 new low-activity waste vaults at SRS 
for disposal of the tank components. With removal of the tanks, 
backfilling of the excavations left after the removal would be 
required.

No Action Alternative

    The No Action alternative would involve leaving the tank systems in 
place after bulk waste removal has been accomplished. After bulk waste 
removal, each tank would contain residual waste, and, in those tanks 
that reside in the water table, ballast water. The tanks would not be 
backfilled.
    After some period of time (probably hundreds of years), the 
reinforcing bar in the roof of the tank would rust and the roof would 
fail, causing the structural integrity of the tank to degrade. 
Similarly, the floor and walls of the tank would degrade over time. 
Rainwater would enter the exposed tank, flushing contaminants from the 
residual waste in the tanks and eventually carrying these contaminants 
into the groundwater. Contamination of the groundwater would be much 
greater and occur much more quickly than it would if the tank were 
backfilled and the residual waste bound with the backfill material.

Environmentally Preferable Alternative

    Overall, the Stabilize Tanks--Fill with Grout alternative is the 
environmentally preferable alternative. Review of the data presented in 
the Tank Closure EIS shows that in the near term the impacts of the 
Stabilize Tanks--Fill with Grout alternative are similar to or less 
than those of the Stabilize Tanks--Fill with Sand and the Stabilize 
Tanks--Fill with Saltstone alternatives.
    Waste removal and, if necessary, cleaning activities would be 
similar for each of these alternatives, although worker exposures and 
resultant latent cancer fatalities would be slightly higher for the 
Stabilize Tanks--Fill with Saltstone alternative due to the 
radionuclide content of the saltstone. In the short term the Clean and 
Remove Tanks alternative would have substantially greater impacts than 
any of the Stabilize Tanks options, as a result of the worker exposures 
that would be required to clean and remove the tanks and tank systems. 
The No Action alternative has the least short-term impacts.
    In the long term, the impacts of the Clean and Remove Tanks 
alternative would be the least of all the alternatives, because the 
groundwater contaminant source term would have been removed. Some small 
long-term impacts would result from release of contaminants from the 
disposal facility that would receive the tank systems after removal. 
Long-term impacts of the preferred alternative, Stabilize Tanks--Fill 
with Grout, would be greater than those of the Clean and Remove Tanks 
Alternative, although very small; no latent cancer fatalities would 
result from implementation of the Stabilize Tanks--Fill with Grout 
alternative. The No Action alternative has the greatest long-term 
impacts.

Decision

    DOE has selected the preferred alternative identified in the Final 
EIS, Stabilize Tanks--Fill with Grout, to guide development and 
implementation of closure of the high-level waste tanks and associated 
equipment at SRS. Following bulk waste removal, DOE will clean the 
tanks if necessary to meet the performance objectives contained in the 
General Closure Plan and the tank-

[[Page 53787]]

specific Closure Module and then fill the tanks with grout.
    In parallel with tank closures, DOE will evaluate and consult with 
SCDHEC on closure methods and regulatory revisions that will allow 
accelerated closure and reduction of risk associated with the HLW 
tanks. DOE remains committed to closure of the HLW tanks in accordance 
with the approved General Closure Plan.
    DOE has selected the Stabilize Tanks--Fill with Grout alternative 
for several reasons. First, DOE has confidence in the method due to the 
demonstrated performance of the reducing grout and the successful waste 
removal and closure process employed for Tanks 17 and 20. On the basis 
of the analysis in the EIS, the selected alternative is superior to the 
Fill with Sand and Fill with Saltstone options in terms of binding 
residual waste in the tanks and thereby preventing future environmental 
contamination. This alternative would likely require the least tank 
cleaning of any alternative and would therefore minimize worker 
exposures and waste management concerns while meeting the performance 
objectives. In addition, this alternative was found to be the 
environmentally preferable alternative.
    As described in the EIS, bulk waste removal has been demonstrated 
to remove about 97 percent of the radioactive material content, 
measured in curies, from a HLW tank. Spray water washing has been shown 
to remove slightly less than an additional one percent and generates 
additional wastewater that requires processing. DOE will employ spray 
water washing or an enhanced cleaning method only if it is necessary to 
meet the performance objectives.
    In accordance with the General Closure Plan, DOE must demonstrate 
whether residual waste (that is, waste that will remain in the tank 
following any necessary cleaning, and that will be immobilized in the 
grout used to stabilize the tank) is low-level or transuranic waste in 
accordance with the Waste Incidental to Reprocessing provision in DOE 
Order 435.1. However, because DOE must meet overall performance 
standards in any case, the regulatory status of the residual waste does 
not affect the assessment of environmental impacts.

Mitigation

    DOE is committed to environmental stewardship and to operating the 
SRS in compliance with all applicable laws, regulations, DOE Orders, 
permits, and compliance agreements. In addition to good engineering 
practice, closure of the HLW tanks will follow the approved Industrial 
Wastewater Closure Plan for the F- and H-Area High-Level Waste Tank 
Systems, known as the General Closure Plan, and the individual Tank 
Closure Modules required by the General Closure Plan. This process will 
serve to ensure that risks are minimized and the environmental and 
health and safety impacts of tank closure are within the bounds 
described in the Final EIS. DOE considers this process to be standard 
operating procedures that do not require a mitigation action plan under 
10 CFR 1021.331(a).

    Issued at Washington, DC, August 9th, 2002.
Paul M. Golan,
Acting Assistant Secretary for Environmental Management.
[FR Doc. 02-20968 Filed 8-16-02; 8:45 am]
BILLING CODE 6450-01-P