Alternatives for High-Level Waste Salt Processing at the Savannah River Site (2000) / Chapter Skim
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Appendix B: Interim Report
Appendix B: Interim Report
Pages 102-129
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From page 102... ...
Appendix B Interim Report 102
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From page 103... ...
.. ~ (.\ .C,,, o-Board on Radioactive Waste Management National Research Council October 14, 1999 The National Research Council empaneled a committee' at your requests to provide an independent technical review of alternatives for processing the high-level radioactive waste salt solutions at the Savannah River Site3.
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From page 104... ...
These processes were grouped into an "initial list" of 18 alternative processing options, which were subsequently screened using a multi-attribute analysis to obtain a Short list" of four alternative processing options: small tank tetraphenylborate (TPB) precipitation, caustic side solvent extraction, direct disposal in grout, and crystalline silicotitanate (CST)
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From page 105... ...
For the small tank TPB precipitation, caustic side solvent extraction, and CST ion exchange processing options, the remaining hurdles are both scientific and technical in nature and include the need for obtaining a better understanding of basic chemical processes. The direct disposal in grout option appears to be technically mature but faces significant regulatory hurdles.
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From page 106... ...
The committee believes that WSRC must obtain a better understanding of the chemistry of the TPB decomposition process before this option could be selected and deployed to treat the cesium-bearing salt solutions at Savannah River. The extreme complexity of the chemical system in the alkaline tank waste at Savannah River which consists of more than 35 elements in a variety of phases and chemical compounds, including solid and liquid complexesincreases the likelihood that significant and unanticipated technical problems will be encountered unless benzene generation and release processes are better understood'°.
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From page 107... ...
Second, CST appears to react with constituents in the alkaline tank waste to produce new solid phases that may be capable of plugging the ion exchange columns. Because either of these problems could lead to extended and costly shutdowns of tank waste processing operations at the site if this processing option were to be implemented, these problems must be resolved before this process can be deployed.
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From page 108... ...
As noted in Attachment C, the four cesium removal options discussed above are designed to process waste streams that have been treated to remove actinides and strontium. Savannah River plans to remove these radionuclides at the "front end" of processing operations by treating the waste with monosodium titanate (MST)
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From page 109... ...
In FY99, R&D funding for the four alternative processing options totaled about $11 million about $4.4 million for small tank TPB, $6.0 million for CST ion exchange, $0.3 million for caustic side solvent extraction, and $0.3 million for direct disposal in grout. Funding for the R&D work on solvent extraction was provided not by WSRC, but through DOE's Office of Science and Technology.
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From page 110... ...
As noted previously, DOE plans to release a draft EIS in October 1999 that will be used as a basis for a spring 2000 ROD that selects a single processing option WSRC is now in the process of preparing the draft EIS, and the committee was told by WSRC staff that the draft EIS would likely recommend the selection of small tank TPB precipitation as the preferred processing option. Based on the committee's initial review of the processing options, it is not clear that the small tank TPB precipitation option favored by WSRC will necessarily be the committee's preferred choice after the committee's detailed review is completed.
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From page 111... ...
A vigorous, well planned, and adequately funded R&D effort should be undertaken to address the remaining scientific and technical hurdles with the caustic side solvent extraction option. This R&D should address, at a minimum, the stability of the solvent system in radiation fields, the ability to scrub and recycle the solvents, the ability to mitigate contaminant formation during processing, and the ability to produce the chelating agent in quantities necessary for this application.
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From page 112... ...
, Downers Grove, Illinois NRC Staff KEVIN CROWLEY, Study Director DOUGLAS RABER, Director, Board on Chemical Sciences and Technology ROBERT ANDREWS, Senior Staff Officer, Board on Radioactive Waste Management JOHN WILEY, Senior Staff Officer, Board on Radioactive Waste Management LATRICIA BAIL KY, Project Assistant MATTHEW BAXTER-PARRO11, Project Assistant
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From page 113... ...
About 90 percent ofthis volume is comprised of salts and salt solutions Blat contain high lends of radioactive cesium, which was to be removed by the ITP process prior to treatment and immobilization. A systems engineenag evaluation of all highlevel waste salt separation prom was ~ completed as a reset ofthe problem myth the IllP process.
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From page 114... ...
I would like this review to address the following points: Was an appropnate}y comprehensive set of cesium partitioning alternatives identified and are there other alternatives that should be explored? Was the process used to screen the alternatives technically sound and did its application result in the selection of appropriate preferred alternatives?
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From page 115... ...
Ralph Erickson and his staff are the Department's principal points of contact for this work. The Environmental Management Program will fiend this project under the cooperative agreement with the Councit's Board on Radioactive Waste Management (DE-FCO1-99EW59049)
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From page 116... ...
has the responsibility for waste management at the Savannah River Site and has implemented a program to stabilize this high-level waste and close the tank farms. The information used in this attachment is taken from the documents cited in Attachment E and from copies of the presentations provided at the committee's first information-gathering meeting.
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From page 117... ...
~ ~ A - Administration Area i Savannah River Technology Center B - Securirv and Engineenng Area C - Reactor Area 1:~- Heavy Water Facility and Power House E- Burial Grounds F - Separations Area ~ F-Tank Fann H - Separations Area / H-TanI; Farrn K - Reactor Area L- Reactor Area M - Materials Area ~ ~~` North \_ ~ Carolina \ South \ \ Carolina >I Augusta Hi; /< ~ SRS ~ Georgia \~; Savannah N - Central Shops Area P - Reactor Area R- Reactor Area S - Defense Waste Processing Facilirv T - Large Scale Test Facilirv Z - Saltstone Area RR- RailRoad Yard SR Forest Station PAR Pond - Manmade cooling pond for P and R reactors L Lake- Manmade cooling pond for L reactors FIGURE C.1. Map showing location of the Savannah River Site 117
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From page 118... ...
1999 Page 16 EXTENDED SLUDGE PROCESSING r ~ jot/ TANK FARMS SALT PROCESSING I i I Process To Be Determined MST Process _ If/ book' _ Glass to Storage and Disposal DWPF (VITRIFICATION) Residual Salt .
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From page 119... ...
The residual solutions are classified as "incidental waste" from the processing of high-level waste. Saltstone is created by mixing the residual salt solutions with fly ash, slag, and Portland cement to create a grout slurry.
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From page 120... ...
The removal of cesium from the salt solutions is potentially feasible through a number of processes, for example, precipitation reactions, ion exchange, or solvent extraction. In the 1 980's, Savannah River developed a process for removing cesium from salt solutions through a precipitation reaction involving sodium tetraphenylborate (TPB)
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From page 121... ...
Although ion exchange for cesium removal has been used in the nuclear industry, CST ion exchange has never been used in a large-scale waste application, and CST has never been manufactured in commercialscale quantities. Caustic side solvent extraction also is based on conventional solvent extraction concepts, such as those used in the widely known PUREX process to separate U and Pu from dissolved irradiated targets.
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From page 122... ...
Savannah River performed a flowsheet analysis, risk analysis, and lifecycle cost analysis of the four alternatives in late 1998. Based on this analysis, WSRC recommended small tank TPB as the preferred alternative and CST ion exchange as the backup alternative.
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From page 123... ...
We wish to thank the following individuals for their participation in the review of this report: Andrew Campbell, U.S. Nuclear Regulatory Commission Rodney Ewing, University of Michigan Mary Good, Venture Capital Investors, LLC Michael Kavanaugh, Malcoim-Pirnie, Inc.
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From page 124... ...
1998. Independent Assessment of the Savannah River Site High-Level Waste Salt Disposition Alternatives Evaluation.
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From page 125... ...
Savannah River Site, High Level Waste Salt Disposition Systems Engineering Team.
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Savannah River Site, High Level Waste Salt Disposition Systems Engineering Team.
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From page 127... ...
Draft High Level Waste Salt Disposition Interface Requirements. Revision C
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From page 128... ...
Doug Walker, SRTC Roy Jacobs, WSRC John Harbour, SRTC Dan Lambert, SRTC Bill Wilmarth, SRTC Caustic Side Solvent Extraction Option. Ken Rueter, WSRC Ralph Leonard, Argonne National Laboratory Bruce Moyer, ORNL Reid Peterson, SRTC John Fowler, WSRC Direct Disposal in Grout Option.
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From page 129... ...
This review will address the following points: Was an appropriately comprehensive set of cesium partitioning alternatives identified, and are there other alternatives that should be explored? Was the process used to screen the alternatives technically sound and did its application result in the selection of appropriate preferred alternatives?
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