[Federal Register Volume 66, Number 201 (Wednesday, October 17, 2001)]
[Notices]
[Pages 52752-52756]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-26082]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF ENERGY


Record of Decision: Savannah River Site Salt Processing 
Alternatives

AGENCY: Department of Energy (DOE).

ACTION: Record of Decision.

-----------------------------------------------------------------------

SUMMARY: The Savannah River Site Salt Processing Alternatives 
Supplemental Environmental Impact Statement (Salt Processing SEIS, DOE/
EIS-0082-S2) considered alternatives for separating the high-activity 
fraction from the low-activity fraction of the high-level radioactive 
salt waste now stored in underground tanks at the Savannah River Site 
(SRS) near Aiken, South Carolina. Based on the analysis in the SEIS and 
the results of laboratory scale research and development and 
independent reviews, DOE determined that any of the alternatives 
evaluated could be implemented with only small and acceptable 
environmental impacts. DOE has decided to implement Caustic Side 
Solvent Extraction for separation of radioactive cesium from SRS salt 
wastes because the solvent extraction process is robust and efficient, 
and DOE has experience with similar solvent extraction processes such 
as PUREX (Plutonium--Uranium Extraction).
    Initial implementation of the Caustic Side Solvent Extraction 
technology will consist of designing, constructing, and operating a 
facility in S-Area. DOE will evaluate the processing capacity needed 
based on high-level waste system requirements (including, but not 
limited to, waste removal capabilities, optimization of salt-sludge 
blending for Defense Waste Processing Facility operations, and 
saltstone system modifications or upgrades), projected throughput, and 
conceptual design data. Based on these evaluations, DOE may elect to 
build a facility or facilities to carry out the Caustic Side Solvent 
Extraction process that could accommodate pilot program and production 
objectives, but would not exceed the size or processing capacity 
evaluated in the Salt Processing SEIS.
    In parallel, DOE will evaluate implementation of any of the other 
salt processing alternatives for specific waste portions for which 
processing could be accelerated or that could not be processed in the 
Caustic Side Solvent Extraction facility. These evaluations and 
potential operations would be undertaken to maintain operational 
capacity and flexibility in the HLW system, and to meet commitments for 
closure of high-level waste tanks.

ADDRESSES: Copies of the Salt Processing SEIS 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. The SRS Salt 
Processing Alternatives SEIS (including the 38-page Summary) is 
available on the Department of Energy NEPA Web site, tis.eh.doe.gov/nepa/docs/docs.htm. This Record of Decision also will be available at 
the above Web site.

FOR FURTHER INFORMATION CONTACT: Questions concerning the SRS Salt 
Processing program can be submitted by

[[Page 52753]]

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 operations at the SRS resulted in the 
generation of large quantities of high-level radioactive waste (HLW), 
which is stored onsite in large underground tanks. SRS HLW was 
generated as an acidic solution and was chemically converted to an 
alkaline solution for storage. In its alkaline form it consists of two 
components, soluble salt and insoluble sludge. Both components contain 
highly radioactive residues from nuclear materials production. 
Radionuclides found in the sludge component include fission products 
(such as strontium-90) and long-lived actinides (such as uranium and 
plutonium). Radionuclides found in the soluble salt component include 
isotopes of cesium and technetium, as well as some strontium and 
actinides. DOE has been operating the Defense Waste Processing Facility 
(DWPF) since 1996 to vitrify (convert to glass) the sludge component of 
HLW to a stable form suitable for disposal in a geologic repository.
    DOE continues to manage the salt component within the HLW tank 
system. Dewatering the salt solution by evaporation, a process that 
conserves tank space, converts the salt solution to a solid saltcake 
and a concentrated salt supernatant. In order to process the salt 
component using any action alternative described in the Salt Processing 
SEIS, DOE must first convert the saltcake back to salt solution. Solid 
saltcake would be dissolved by adding water and combined with salt 
supernatant to form a salt solution. The highly radioactive 
constituents would be separated from the salt solution and vitrified in 
DWPF. The remaining low-activity constituents, consisting mostly of 
non-radioactive salts, would be stabilized with grout (a cement-like 
mixture) to create a saltstone waste form for disposal at the SRS as 
low-level radioactive waste.
    DOE evaluated the potential environmental impacts of constructing 
and operating DWPF in a 1982 EIS (DOE/EIS-0082). In 1994 DOE published 
a SEIS (DOE/EIS-0082-S) evaluating changes in the HLW process proposed 
after the 1982 EIS was issued. The Record of Decision (60 FR 18589; 
April 12, 1995) announced that DOE would complete the construction and 
startup testing of DWPF using the In-Tank Precipitation (ITP) process 
to separate the high-activity fraction from the salt solution.
    DOE designed the ITP process to be carried out primarily in one of 
the underground HLW storage tanks. Under the ITP process an inorganic 
sorbent, monosodium titanate, would have removed actinides and 
radioactive strontium from the salt solution and an organic reagent, 
sodium tetraphenylborate, would have precipitated radioactive cesium 
from the salt solution. The ITP process included washing and filtration 
steps to separate the resulting solids and residual sludge for 
vitrification in DWPF. However, tetraphenylborate is subject to 
catalytic and radiolytic decomposition that returns cesium to the salt 
solution and generates benzene, which is a toxic, flammable, and 
potentially explosive organic substance that must be safely controlled. 
The ITP process was designed to accommodate some tetraphenylborate 
decomposition and to limit benzene accumulation. To achieve the 
objectives of the ITP process, however, the decomposition of 
tetraphenylborate must be limited to minimize (1) the amount of 
precipitated cesium that is redissolved in the salt solution and (2) 
the amount of benzene generated. Startup testing of the ITP facility in 
1995 generated benzene in much greater quantities than had been 
anticipated based on calculations and laboratory experiments, and ITP 
startup operations were suspended in order to develop a better 
understanding of the ITP process chemistry.
    In August 1996, the Defense Nuclear Facilities Safety Board 
(DNFSB), chartered by Congress to independently review operations at 
DOE nuclear defense facilities and to make recommendations necessary to 
protect public health and safety, recommended that planned large-scale 
testing of the ITP process not proceed further until DOE had a better 
understanding of how benzene was generated and released during the 
precipitation process. In response to the DNFSB recommendation, DOE 
initiated an extensive chemistry program to better understand the 
process of benzene generation and release. In January 1998, DOE 
determined that ITP, as designed, could not meet production goals and 
safety requirements, because the separation of radionuclides from HLW 
salt solution could not be achieved without excessive tetraphenylborate 
decomposition and benzene generation. DOE must therefore select an 
alternative technology for HLW salt processing.

Alternative Technology Evaluation

    Westinghouse Savannah River Company (WSRC), the SRS operating 
contractor, evaluated a list of over 140 potential salt treatment 
technologies to replace the ITP process and in October 1998 recommended 
four technologies for further consideration: Small Tank 
Tetraphenylborate Precipitation (Small Tank), Crystalline 
Silicotitanate Ion Exchange (Ion Exchange), Caustic Side Solvent 
Extraction (Solvent Extraction), and Direct Disposal in Grout (Direct 
Disposal). DOE decided in early 1999 to pursue three of the four 
candidate alternatives for replacement of the ITP process, dropping 
Solvent Extraction because it was considered technically immature for 
the salt waste at that time.
    In addition to engineering and research and development efforts, 
reviews by the National Academy of Sciences have played an important 
role in reviewing DOE's technology selection process. In June 1999 the 
Under Secretary of Energy requested that the National Academy of 
Sciences--National Research Council provide an independent technical 
review of alternatives for processing the HLW salt at the SRS. In 
response to the request, the Council appointed a ``Committee on Cesium 
Processing Alternatives for High-Level Waste at the Savannah River 
Site,'' which conducted a review and provided an interim report in 
October 1999 and a final report in August 2000. Based on that report's 
recommendation and new research and development results from 
independent work at Oak Ridge National Laboratory, DOE restored Solvent 
Extraction to the list of potential alternatives. In connection with 
the August 2000 report, DOE asked the Council to provide a follow-on 
assessment, and the Council appointed a ``Committee on Radionuclide 
Separation Processes for High-Level Waste at the Savannah River Site'' 
in October 2000 to review DOE's evaluation of potential technologies 
for separating radionuclides from soluble high-level radioactive waste 
at the SRS. This second committee conducted its review and provided an 
interim report in March 2001 and a Final Report in June 2001. The 
report concluded that Caustic Side Solvent Extraction technology 
presents the least technical uncertainties of any of the three cesium 
separation alternatives.

[[Page 52754]]

Alternatives Considered

    The Salt Processing SEIS describes the environmental impacts of the 
four salt processing technology alternatives that were evaluated 
through engineering and research and development efforts and 
independent technical reviews. The four salt processing technology 
alternatives considered in the Salt Processing SEIS were Small Tank, 
Ion Exchange, Solvent Extraction, and Direct Disposal. The analysis in 
the Salt Processing EIS is based on pre-conceptual engineering designs 
of the facilities and emissions estimates generated from knowledge of 
chemical processes and engineering controls that would be applied. The 
Salt Processing SEIS also analyzed a No Action alternative (i.e., a 
continuation of current HLW management activities).
    The four salt processing technology alternatives considered in the 
Salt Processing SEIS share some common features. Each alternative 
includes initial separation of low-concentration soluble radioactive 
strontium and actinides (including plutonium) by sorption, followed by 
filtration. The essential difference among the alternatives is the 
technology for removal of the relatively high concentrations of 
radioactive cesium. Except for the Direct Disposal alternative, in 
which cesium would not be removed but would remain in the fraction 
immobilized as saltstone for disposal at the SRS, the final waste forms 
are similar for each of the action alternatives. For these action 
alternatives the cesium is extracted from the salt solution and 
incorporated into a vitrified waste form for eventual repository 
disposal, and the remaining low-activity salt fraction is immobilized 
as saltstone for disposal at the SRS.

Solvent Extraction

    The Solvent Extraction alternative, identified as the preferred 
alternative in the final Salt Processing SEIS, would use a highly 
specific organic extractant to separate cesium from the HLW salt 
solution. The cesium would be transferred from the aqueous salt 
solution into an insoluble organic phase, using a centrifugal contactor 
to provide high surface area contact, followed by centrifugal 
separation of the two phases. Recovery of the cesium by back extraction 
from the organic phase into a secondary aqueous phase would generate a 
concentrated cesium solution for vitrification in DWPF.

Small Tank Precipitation

    The Small Tank Precipitation alternative would use 
tetraphenylborate precipitation, the same chemical reaction as in ITP, 
to remove the radioactive cesium from the HLW salt solution. The 
process would be conducted as a continuous operation using a small, 
temperature-controlled reaction vessel to inhibit tetraphenylborate 
decomposition and benzene generation. The vessel and operating 
conditions would be designed to minimize benzene emission and 
flammability hazards by maintaining an inert gas (i.e., nitrogen) 
atmosphere within the reaction vessel. DOE learned from the ITP process 
experience that temperature control and maintenance of an inert 
atmosphere are important for safe and efficient tetraphenylborate 
precipitation.

Ion Exchange

    The Ion Exchange alternative would use crystalline silicotitanate 
resin in ion exchange columns to separate cesium from the salt 
solution. The salt solution would be passed through large stainless 
steel ion exchange columns filled with the ion exchange resin to react 
the cesium with the resin. Treatment of the solution to separate 
strontium and actinides, followed by filtration to remove the solids 
and residual sludge, would be necessary prior to separating the cesium 
to prevent plugging the ion exchange columns.
    The Ion Exchange process would result in the accumulation of as 
much as 15 million curies of radioactive cesium on the resin inventory 
within the process cell. This radioactive loading would require 
stringent shielding and operational controls because of high radiation, 
high heat generation, and the generation of hydrogen and other gases.

Direct Disposal in Grout

    As indicated earlier in this section, under the Direct Disposal 
alternative the HLW salt solution would be disposed of at SRS as 
saltstone, without prior separation of radioactive cesium. The 
resulting saltstone would have radionuclide concentrations less than 
Class C low-level waste (LLW) limits, but would exceed Class A limits, 
as defined in U.S. Nuclear Regulatory Commission (NRC) regulations at 
10 CFR 61.55. These waste classifications do not apply to DOE-generated 
LLW, but DOE used the NRC classification system in the Salt Processing 
SEIS to describe differences in waste forms because DOE Manual 435.1-1 
establishes a process for making waste-incidental-to-reprocessing 
determinations in terms of the NRC classifications. The current 
Saltstone Facility permit, which was issued by the South Carolina 
Department of Health and Environmental Control (SCDHEC) under its State 
wastewater authority, authorizes disposal of wastes with radionuclide 
concentrations comparable to Class A LLW. Under the permit, DOE must 
notify SCDHEC if the characteristics of wastes in saltsone vaults would 
change, as would be the case with the higher level of radioactivity in 
the final waste form under the Direct Disposal alternative. Also, if 
this alternative were implemented, cesium would not be present in 
sufficient concentrations in DWPF canisters to make the canisters 
``self-protecting.'' This characteristic would be necessary for DOE to 
carry out immobilization of certain plutonium materials, as described 
in the Surplus Plutonium Disposition EIS (DOE/EIS-0283) and the 
associated Record of Decision (65 FR 1608; January 11, 2000).

No Action

    Under the No Action alternative in the near term, DOE would 
continue current HLW management activities, including tank space 
management, without a process for separating the high-activity from the 
low-activity salt fractions. DWPF would vitrify only sludge from the 
HLW tanks. Saltcake and salt supernatant would be stored in the HLW 
tanks and monitoring activities would continue. DOE would continue to 
manage tank space to ensure adequate space to meet safety requirements 
and closure commitments. Current tank space management projections 
indicate that additional tank space would be needed after 2010 to 
support continuing operations under the No Action alternative.
    Without a salt processing technology in place, however, current HLW 
storage operations could not continue indefinitely. DWPF operations 
result in large volumes of waste, mostly water, which is returned to 
the HLW tanks. DOE uses evaporators to substantially reduce this 
volume, but until a salt processing technology is on-line, DWPF 
operation will increase rather than decrease the volume of HLW that 
must be stored in the tanks.

Environmentally Preferable Alternative

    Ion Exchange is the environmentally preferable alternative. Review 
of the data presented in the Salt Processing SEIS shows that the 
construction and operation activities to implement the Ion Exchange 
alternative would have impacts that are generally small and similar to 
the other action alternatives. However, because the Ion Exchange 
alternative does not use organic materials that generate organic

[[Page 52755]]

compounds (such as benzene) that must be treated, there are no organic 
emissions that must be managed. Organic compounds used in the Solvent 
Extraction and Small Tank alternatives result in organic emissions that 
must be safely managed. Also, certain accidents involving volatile 
organic compounds could not occur with the Ion Exchange alternative. 
Ion Exchange would result in the lowest radiological dose to the worker 
population and the public, although none of the alternatives would 
result in adverse health effects from radiological releases during 
construction and normal operation.
    The No Action alternative is the least desirable both in the short 
term, because of the impacts of construction and operation of new HLW 
tanks, and in the long term because of the unacceptably high quantity 
of HLW contaminants that could be released to onsite streams.
    In the short term the Direct Disposal alternative would in many 
cases generate the least effluents of any of the processing 
alternatives. However, in the long term Direct Disposal would release 
greater quantities of contaminants to the environment than would the 
other processing alternatives because of the much greater concentration 
of cesium that would be disposed of in saltstone. For this reason 
Direct Disposal cannot be considered the environmentally preferable 
alternative.

Comments on the Final Supplemental EIS

    On July 30, 2001, the Defense Nuclear Facilities Safety Board 
(DNFSB) commented on DOE's identification of the Solvent Extraction 
alternative as the preferred technology for processing salt waste at 
SRS. DNFSB urged DOE to pursue a back-up technology through pilot scale 
operations to give DOE more flexibility in addressing unforeseen 
technical or programmatic issues. The DNFSB letter identified the Small 
Tank Precipitation alternative as an apparently appropriate back-up 
technology. The DNFSB letter also stated the belief that DOE would 
benefit from further assessment of direct disposal of low-source-term 
wastes. In an August 24, 2001, response to the DNFSB letter, DOE 
expressed appreciation for the DNFSB's perspective on the technologies 
and associated technical challenges, and pledged to continue to work 
closely with the DNFSB and its staff to communicate the bases of the 
DOE approach as well as progress on assuring that the project proceeds 
safely and effectively. DOE will continue laboratory testing of the 
other technologies in support of potential future needs as a backup 
technology and as potential technologies for processing specific 
portions of the HLW until such time as a Solvent Extraction facility is 
operational and has proven successful.
    By letter dated August 15, 2001, the United States Environmental 
Protection Agency, Region 4 (EPA) commented on the Final Salt 
Processing SEIS. EPA stated that the disposal routes and locations for 
secondary waste streams, including low-level waste that would be 
generated from the Small Tank and Solvent Extraction technologies, were 
not discussed clearly in the EIS. On June 28, 2001, DOE published an 
Amended Record of Decision (66 FR 34431) for the SRS Waste Management 
EIS (DOE/EIS-0217, July 1995), announcing DOE's decision to ship 
certain SRS low-level and low-level mixed waste streams offsite for 
treatment and disposal at commercial or Government facilities. DOE will 
select among the disposal options considered in the SRS Waste 
Management EIS, depending upon the volume and characteristics of the 
salt processing alternative waste stream, and the costs of treatment 
and disposal. The Final Salt Processing SEIS acknowledges the 
possibility of offsite treatment or disposal for certain waste streams, 
but at this time DOE cannot be more specific about which disposal 
options would eventually be chosen.
    EPA requested clarification on the current viability of the 
Consolidated Incineration Facility and other options for treatment of 
mixed low-level waste. As is explained on page 1-4 of the Final Salt 
Processing SEIS, DOE expects to decide whether to resume CIF operations 
by April 2002. DOE is investigating alternatives to incineration and 
will not operate the CIF if an effective alternative disposition of 
PUREX solvents can be identified.

Decision

    DOE has decided to implement Caustic Side Solvent Extraction for 
separation of radioactive cesium from SRS salt wastes. The results of 
research and development activities were an important factor in DOE's 
selection of a salt processing technology. DOE has performed research 
on each of the three cesium removal technology alternatives since 1998. 
Independent scientists and subject matter experts have reviewed the 
results of the research and assessed the advantages and disadvantages 
associated with each of the identified alternatives, considering life 
cycle costs and schedules for the design, construction, and operation 
of each alternative. In addition to, and in consideration of this 
research, analysis, and independent review, DOE conducted a final 
management review that comparatively evaluated each of the action 
alternatives against a list of criteria that included cost, schedule, 
technical maturity, implementability, environmental impacts, facility 
interfaces, process simplicity, process flexibility, and safety.
    Although Solvent Extraction uses a complex four-component solvent 
system, laboratory testing has clearly shown that component 
concentration and process flow can be maintained to effectively remove 
cesium from the wastes. Other key strengths identified for the Solvent 
Extraction technology include: (1) Maturity of and experience within 
the DOE complex for solvent extraction processing of nuclear material, 
(2) simplicity with which the Solvent Extraction product stream could 
be incorporated into the current DWPF vitrification process, and (3) 
the ability to rapidly start up and shut down the Solvent Extraction 
centrifugal contactors, which lends flexibility by allowing 
responsiveness to processing contingencies elsewhere in the HLW 
management system. DOE believes the Solvent Extraction process to be 
robust and efficient. In addition, DOE has extensive experience at the 
SRS with a similar solvent extraction process, Plutonium--Uranium 
Extraction (PUREX). The PUREX process has been used in F- and H-Canyons 
at SRS for almost 50 years to extract plutonium and uranium from 
solutions created by the dissolution of nuclear fuel and targets.
    In addition to engineering and research and development efforts, 
the National Academy of Sciences has played an important role in 
evaluating DOE's technology selection process. In June 1999 the Under 
Secretary of Energy requested that the National Academy of Sciences--
National Research Council provide an independent technical review of 
alternatives for processing the HLW salt at the SRS. In response to the 
request, the Council appointed a ``Committee on Cesium Processing 
Alternatives for High-Level Waste at the Savannah River Site,'' which 
conducted a review and provided an interim report in October 1999 and a 
final report in August 2000. Based on that report's recommendation and 
new research and development results from independent work at Oak Ridge 
National Laboratory, DOE restored Solvent Extraction to the list of 
potential alternatives. In connection with the August 2000 report, DOE 
asked the Council to provide a follow-on assessment, and the Council 
appointed a ``Committee on Radionuclide Separation Processes for

[[Page 52756]]

High-Level Waste at the Savannah River Site'' in October 2000 to review 
DOE's evaluation of potential technologies for separating radionuclides 
from soluble high-level radioactive waste at the SRS. This second 
committee conducted its review and provided an interim report in March 
2001 and a Final Report in June 2001. The report concluded that Caustic 
Side Solvent Extraction technology presents the least technical 
uncertainties of any of the three cesium separation alternatives.
    Initial implementation of the Caustic Side Solvent Extraction 
technology will consist of designing, constructing, and operating a 
facility in S-Area. DOE will evaluate the processing capacity needed 
based on the high-level waste system requirements (including, but not 
limited to, waste removal capabilities, optimization of salt-sludge 
blending for Defense Waste Processing Facility operations, and 
Saltstone system modifications or upgrades), projected throughput, and 
conceptual design data. Based on these evaluations, DOE may elect to 
build a Caustic Side Solvent Extraction process facility or facilities 
that could accommodate pilot program and production objectives, but 
would not exceed the size or processing capacity evaluated in the Salt 
Processing SEIS. In parallel, DOE will evaluate implementation of any 
of the other salt processing alternatives for specific waste portions 
for which processing could be accelerated or that could not be 
processed in the Solvent Extraction facility. These evaluations and 
potential operations would be undertaken to maintain operational 
capacity and flexibility in the HLW system, and to meet commitments for 
closure of high-level waste tanks.
    The analysis in the Salt Processing SEIS shows that the 
environmental impacts of the construction and operation of a full-scale 
Solvent Extraction facility would be generally small and similar to 
those of the other processing alternatives. DOE determined that any of 
the alternatives evaluated could be implemented with only small and 
acceptable environmental impacts. The EIS estimates that the radiation 
doses for any of the alternatives would result in a small increase in 
latent cancer fatalities in the worker population and the offsite 
public, but would be well below applicable standards for both 
populations. The Solvent Extraction alternative would generate up to 
900,000 gallons per year of radioactive liquid waste. Most of this 
volume consists of water that would be evaporated, and the remainder 
would be treated at the SRS Effluent Treatment Facility to remove 
radioactive substances and discharged as water meeting drinking water 
standards. The long term (after mission completion and facility 
decommissioning) effect on groundwater quality from residual 
radionuclides released from the saltstone vaults would be small and 
similar for the cesium separation alternatives, and greater, but still 
small, for the Direct Disposal alternative.

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. Construction and operation of the 
salt processing facility will be conducted in accordance with good 
engineering practice that includes measures to minimize the risks 
associated with the construction and operation of any industrial 
facility. DOE considers these to be standard operating procedures that 
do not require a mitigation action plan (under 10 CFR 1021.331(a)).

    Issued at Washington, DC, October 9, 2001.
Jessie Hill Roberson,
Assistant Secretary for Environmental Management.
[FR Doc. 01-26082 Filed 10-16-01; 8:45 am]
BILLING CODE 6450-01-P