Research Reactor Aluminum Spent Fuel Treatment Options for Disposal (1998) / Chapter Skim
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Appendix D. Consultant Reports
Appendix D. Consultant Reports
Pages 129-210
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From page 129... ...
Most significantly, none of the consultants had access to the predecisional draft of the Highly Ennched Uranium Task Force report (DOE, 1992b) discussed in Chapter 5.
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From page 130... ...
With the USSR 'Russia starting to renege on its sale of 500 metric tons of HEU235 (approximately ten times the amount of research reactor fuel) the question of final form for spent aluminum clad or alloyed research reactor Mel is moot.
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From page 131... ...
However, several of the options appear to include separation of the uranium, at least at one or another stage In He process. For example, In the electrometallurgical treatment, which some have recommended be retained as "a secondary and diverse backup" (Technical Strategy for the Treatment, Packaging, and Disposal of Aluminum-Based Spent Nuclear Fuel: A Report of the Research Reactor Spent Nuclear Fuel Task Team, Vol.
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From page 132... ...
so that if the spent fuel is in storage for many decades, the self-protection is weakened, increasing the need for safeguards. Compared with commercial spent fuel, this filet presents greater proliferation risks because of the HEU.
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From page 133... ...
b. "Alternative Aluminum Spent Nuclear Fuel Treatment Technology Development Status Report (U)
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From page 134... ...
the work claims to have completed only two of Tree phases for the canister if the codisposal waste option is assumed; and 3. it is obvious that some of this work must be repeated since both Me Peter Gottlieb presentation and the Savannah River status report talk of investigations in progress to select an appropriate neutron poison material for the codisposal canister.
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From page 135... ...
To these ends, DOE must assure that canisters are acceptable not for only the repository, but also for interim storage as well as for transportation. The Savannah River status report (2.b above)
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From page 136... ...
In my opinion, required use of a neutron poison material with both the direct disposal and the codisposal alternatives represents a significant criticality hazard for the repository a hazard that can be eliminated by use of the melt-dilute alternative. The dilute-melt will pose additional consideration for criticality during processing; however, the processing system can be designed with positive and monitored control.
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From page 137... ...
APPENDIX D Consultant Reports 137 than melt and dilute. Press and dilute would probably be preferred to either direct disposal or codisposal because it could be calTied forward without need of a neutron poison.
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From page 138... ...
M., Savannah River Site Aluminum-CIadt Spent Nuclear Fuel Alternative Cost Study, Rev.
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From page 139... ...
The schedule estimates are based upon assumptions as to delivery of alum~num-based SNF shipping casks and aluminum-based SNF assemblies to Savannah River; upon projected dates at which the venous technologies could be available using a privatization approach (which to date has not been successfi~) for the transfer, storage, and treannent facility costs; and upon the date on which the repository will be ready to accept shipments.
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From page 140... ...
M., Savannah River Site Aluminum-CIadF Spent Nuclear Fuel Alternative Cost Study, Rev.
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From page 141... ...
an examination of the waste-package performance criteria developed by DOE to meet anticipated waste acceptance criteria for disposal of aluminum-based spent fuel and identification of other factors that DOE might consider; and (3) to the extent possible given the schedule for this project, an assessment of the cost and timing aspects associated with implementation of each spent nuclear fuel disposition technology.
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From page 142... ...
Instead of that standard, Section 801 of the Act directed EPA to promulgate standards to ensure protection of public health from high-level radioactive wastes in a deep geologic repository that might be built under Yucca Mountain in Nevada. By this provision, EPA must set
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From page 143... ...
It is assumed here that disposal of the aluminum-based spent fuel would be in Yucca Mountain, co-disposed with glass logs from defense high-level wastes. Therefore, the regulatory approach and waste acceptance basis for aluminum-based spent nuclear filet are the same as those for Yucca Mo~nD~in.
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From page 144... ...
In addition, if the candidate waste, like spent nuclear fuel, contains fissile matenal, the performance assessment must include a criticality safety analysis. The December workshop on this project was
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From page 145... ...
Evaluation of DOE Aluminum-Based Spent Fuel Alternatives The evaluation of the alternatives being considered by DOE for management of aluminum-based spent nuclear fuel began with four questions: · Has DOE-Savannah River identified the appropriate criteria for alum~num-based spent filet from the draft waste acceptance criteria document that has been prepared by the Yucca Mountain program? · Which of the waste forms is likely to be the most acceptable for disposal In a repository relative to commercial spent fuel and vitrified logs?
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From page 146... ...
Direct co-disposal is also the evident limiting case for waste acceptance since it brings the unmodified corrosion characteristics and the higher nuclear reactivity of this spent fuel directly into the repository. The approach seems to be that if the direct co-disposal option yields an acceptable waste form, there is no need for further consideration of waste acceptance in weighing alternatives.
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From page 147... ...
Summary DOE-Savannah River is following a reasonable regulatory approach for establishing the acceptability of waste disposal forms for aluminum-based spent nuclear fuel. It has nearly completed substantial analysis to demonstrate the waste acceptability of the bounding and most promising option, direct co-disposal.
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From page 148... ...
All eight of the non-reprocessing options were discussed including reviews of waste forms, waste containers, and handling/process~ng issues. Results of the studies for metallurgy and corrosion issues and disposal criticality analysis were presented and discussed.
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From page 149... ...
3. Do the inner container designs appear adequate to contain the waste forms resultingirom the various processing options?
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From page 150... ...
Significant remote handling problems are anticipated for the Plasma Arc Treatment option. More design information would need to be available before remote handling assessments could be made.
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From page 151... ...
151 5. Are the technical requirements of the various alternative processing options sufficiently well defined so that reasonable judgments can be made about the likelihood of success of implementing them?
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From page 152... ...
Unknown international "perceptions" appear to be serious concerns, although the research reactors' SNF handling, processing, and disposal are only the "tip of the iceberg" of the national waste problems. This appears to be a very small nonprofliferation issue compared with the overall nonproliferation issues in total waste management, waste disposal, and waste storage.
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From page 153... ...
3. Savannah River Site: FY97 Spent Nuclear Fuel Interim Management Plan.
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From page 154... ...
dry storage of fuel and achievement of a road-ready status for the fuel package, (b) processing and preparation of optional waste forms and corresponding waste form properties, (c)
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From page 155... ...
. T have taken the cue from the Research Reactor Spent Nuclear Fuel Task Team who indicate in reference 3, Sec 6.2, that Direct/Co-Disposal may be regarded as the primary approach with Press and Dilute or Melt and Dilute as backup.
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From page 156... ...
and place it with other waste forms in an efficient array within a container. After outgass~ng to 4.6 torr to remove free water, the container is sealed for placement with other waste forms (e.g., glass logs in a canisters for eventual shipment to the repository.
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From page 157... ...
For evaluation of these test procedures the test matrix proposed by Savannah River is needed (3, Sec 6.0-6.25~. · Press-Dilute Treatment (5, App F)
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From page 158... ...
Question 4: Will any waste forms resulting from any of the alternative processing options be likely to increase internal corrosion of a standard repository container compared to spent commercial file! or vitrified glass logs?
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From page 159... ...
Electrometallurgical Processing This process also involves melting of the waste form and negligible likelihood of introducing water or corrosive species to the container environment. Question 5: What is the status of R&D activities at Savannah River on the Melt-and-Dilute and Co-Disposal options?
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From page 160... ...
The corrosion models and the range over which they apply are examined later at the conclusion of question responses. There are several items which have not been treated explicitly in the literature handouts that may deserve some consideration: · Question 4 above points up the lack of information concerning the choice of material for the waste container and its interactions with the waste form.
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From page 161... ...
Savannah River has not looked for this particular type of relationship. However ~ found it very interesting that specimens in high temperature vapor, corroding in the rapid linear breakaway corrosion mode, continued to corrode by the same breakaway mechanism when transferred to a lower temperature vapor environment.
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From page 162... ...
~ found no significant deficiencies in the Savannah River corrosion program. The water basin corrosion effects have been thoroughly studied.
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From page 163... ...
Tyer, and M.R. Louthan, "Acceptance Criteria for Intenm Dry Storage of Alm'~num-Alloy Clad Spent Nuclear Fuels," WSRC-TR-95-0347 (U)
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From page 164... ...
The cost data contained in the report of the Research Reactor Spent Nuclear Fuel Task Team, Technical Strategy for the Treatment, Packaging, and Disposal of Aluminum-Based Spent Nuclear Fuel, Vols.
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From page 165... ...
Accordingly, there appears to be a reasonable basis to proceed with the refinement of three technologies currently being pursued in detail. The Transfer Facility Project was not included in the FY98 program as listed in the Savannah River Site FY97 Spent Nuclear Fuel Interim Management Plan6 on which the Task Force Report schedule was based.
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From page 166... ...
Are the cost and schedule estimates developed by DOE for the alternative processing options suitable for budget planning purposes? Response.
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From page 167... ...
Are the cost and schedule estimates for implementing the alternative processing options consistent with DOE procedures and systems? If not, has DOE identified what changes must be made to achieve its cost and schedule targets?
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From page 168... ...
It has been confirmed that options involving reprocessing addressed in the report can be accommodated in the overall workload consistent with DOE procedures.25 The December 1997 cost estimates also show a $240 million life cycle cost saving for the reprocess/codisposal option.26 This appears to be an attractive option, but the policy issue on whether to exercise it must be decided by DOE. The Research Reactor Task Force Report recommends a project approach to the program.27 If the line item project route is chosen, DOE procedures provide that cntical milestone decisions for projects under $500 million are made by the local DOE site office.28 Both a project approach and local decision making authority are essential to timely execution of the program (personal opinion)
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From page 169... ...
Department of Energy (DOE) by the Research Reactor Spent Nuclear Fuel Task Team, June 1996, Vol.
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From page 170... ...
Also Krupa, I.F., Savannah River Site Aluminum-CIad Spent Nuclear Fuel Alternative Cost Study Rev ~ (U9, December 12, 1997, Table D-If. 20 Bnefing at Augusta, Georgia meeting, December 2, 1997 (Kar!
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From page 171... ...
58. 28 Breakout session at Augusta, Georgia meeting, December 3, 1997 2(Randy Polnick, DOE-SK)
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From page 172... ...
In addition to the reports and handouts received on the first day of the meeting, we met with a number of technical personnel involved in the program on the second day. These personnel included program participants from Savannah River Site, Argonne, Idaho National Engineering and Environmental Laboratory, and interested members of the public.
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From page 173... ...
In the case of plasma arc treatment, feeding fuel elements, remote maintenance of the rotating fumace, control of the ceramic waste form composition, arid off-gas processing will be significant development concerns. Q: Are there other processing options that should be considered by DOE for disposition of alum~num-based spent fuel?
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From page 174... ...
If direct co-disposal is selected, rNEEL will have the packaging facilities required, based on its role with stainless steel and zircalloy-ciad fi~els.4 Q: Do inner container designs appear adequate to contain the waste forms resulting from the various processing options? A: Although ~ did not examine this In great depth, ~ see no reason why the designs would not be adequate.
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From page 175... ...
For example, if all SNF HEU must be diluted to less than 20 percent before going to the repository, then direct disposal and direct co-disposal are eliminated. Also, if separation of fission products Tom fissile material is forbidden, then all canyon processing options and electrometallurg~cal treahnent are eliminated.
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From page 176... ...
Based on my judgment and the information in the technical strategy document, ~ would rank them as follows (highest likelihood of success at top of list)
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From page 177... ...
"Alternative Aluminum Spent Nuclear Fuel :~ Treatment Technology Development Status Report (U) ," WSRC-TR97-00345, October 1997.
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From page 178... ...
Al-SNF is therefore considered to be a greater criticality safety concern throughout treatment, interim storage, transport, and final storage than Spent Nuclear Fuel (SNF) from commercial power plants.
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From page 179... ...
Although few, if any, specific criticality safety evaluations are complete, scoping work indicates sufficient safety can be provided by standard means such as limiting Missile quantity, including neutron absorbers, and for the near-term, limiting configurations. In addition, information from in-progress and planned tests will be used to determine if additional criticality safety resources are needed.
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From page 180... ...
Criticality Safety at Savannah River Site (SRS) Many proposed activities with Al-SNF at SRS are similar to past activities, there and elsewhere, with aluminum-based nuclear fuels.
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From page 181... ...
The problem is usually one of adequately balancing criticality safety with process efficiency during process development. Criticality safety methodology at SRS is well developed due to its many years of nuclear experience with reactor operations, fuel storage, fuel processing via chemical reactions, and associated fissile material handling.
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From page 182... ...
Neither SRS nor Yucca Mountain criticality safety personnel typically perform many transportation evaluations. However, cask vendors, license holders, and several DOE contractor sites have well established criticality safety methodology to satisfy transportation criticality safety evaluation requirements.
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From page 183... ...
Of SRS favored options, this one is judged to be most vulnerable to a criticality accident because the waste form is repackaged fuel assemblies, still qualifying as highly enriched uranium in which each assembly, if flooded, is nearly optimally moderated. If adequate criticality safety can be assured for this option, adequate safety can be assured, perhaps with different strategies, for other favored but less wInerable options.
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From page 184... ...
For example, if a condition's calculated Go iS 0.3, it iS more Vapors to demonstrate that the condition's actual Go satisfies the required margin, in this case does not exceed 0.95, than to demonstrate that the calculated An iS within a few percent of the actual luff. Intact Canisters and A1-SNF, Initial Repository Conditions Traditional cnticality safety requirements, concerns, and issues apply to the final repository initially because workers could be at risk if a criticality accident were to occur and because evaluations and corrective actions could be undertaken in a reasonable manner if problems develop.
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From page 185... ...
If ORR fuel with fixed neutron absorbers is acceptable, it should be possible to qualify canisters of the more reactive Al-SNFs, possibly with fewer fuel assemblies and the same neutron absorber or with the same number of filet assemblies and more effective neutron absorbers (for example, thicker metal plates or higher concentrations in metal)
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From page 186... ...
This reviewer believes that, if critical excursion prevention continues to be a very high priority for this phase, Al-SNF treatmentts) that significantly dilute 235u and/or which introduce significant neutron absorbers in the filet matrix should be selected to better assure continued · mlxmg.
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From page 187... ...
Of SRS favored options, this one will result in the most reactive permanent storage configuration. If adequate criticality safety can be assured for this configuration and waste form, then staff should be able to assure adequate criticality safety for less reactive configurations and waste forms.
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From page 188... ...
1997. "Use of Bias, Uncertainty, and Subcritical Margins at the Savannah River Site." In Proceedings, Criticality Safety Challenges in the Next Decade, Chelan, Washington, September 7-} I, 1997.
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From page 189... ...
1997. "Instruction to the Technical Experts, Draft." Memoranda for Technical Options for Disposition of Al-Based Spent Nuclear Fuel.
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From page 190... ...
2. Research Reactor Spent Nuclear Fuel Task Team (June 1996~.
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From page 191... ...
1995. "Preliminary Requirements for the Disposition of DOE Spent Nuclear Fuel in a Deep Geologic Repository," A00000000-00811-1708-00006, Rev0.
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From page 192... ...
Proliferation Assessment United States is a Weapons State Safeguards Capability in the United States is internationally accepted. The Task Team Report included proliferation resistance for 5 percent of its Kepner-Tregoe evaluation.
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From page 193... ...
It might even force the choice to the meTt-dilute alternative, even if other considerations point elsewhere. In theory, it would be fine if all fissionable material were in forms or storage that meet either the "Spent Fuel Standard" or the "Stored Weapons Standard" described by the NAS report Management and Disposition of Excess Weapons Material.
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From page 194... ...
DOE has said that it will be conservative and wait 100 years. These DOE containers will be surrounded by thousands of containers of spent fuel or HEW in the repository.
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From page 195... ...
The final environmental impact statement summary on policy conceding foreign research reactor spent fuel (DOE/ElS-0218F Feb. 1996, referred to as FElS-96S)
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From page 196... ...
to Support this Contention be Provided for Assessment? As noted above, the ROD on FRRFM and the FETS-96S call for an "independent study on the nonproliferation and other implications of reprocessing of spent fuel from foreign research reactors." This statement makes it obvious that a study should include processing options among the alternatives.
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From page 197... ...
Use of Processing for Waste Management Processing has been used and will continue to be used as long as it is needed and facilities to do it are available for damaged or corroded spent fuel that might leak or cause contamination. However, DOE has taken the position that unless it is a health and safety matter, processing should not be used as a step In radioactive waste management.
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From page 198... ...
International Implications It is not credible to say that the choice of technology the United States makes for managing this spent fuel will have any effect on nonproliferation decisions other nations will make. Independence It is difficult to accept a report done by the nuclear nonproliferation of DOE as independent In such a controversial area.
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From page 199... ...
However, the return of fuel from research reactors could stretch on into the future until long after it would be economical to maintain the canyons in operation and then some other process like D-D or M-D would need to be used. Processing Direct Disposal.
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From page 200... ...
Aluminum forms a protective oxide film under these conditions and there would be virtually no measurable reaction of the waste form with the atmosphere or the canister for the years or decades that the waste may wait for placement in Yucca Mountain. The formation and stability of this oxide on various aluniinum alloys is well established in the technical literature for temperatures near room temperature [4]
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From page 201... ...
Yes, for the two processes under serious study, namely Direct Disposal and Melt Dilute. However, WSRC is not trying to prepare a basis for all of the processes considered in the report of the Research Reactor Task Team Study (lack DeVine, Chairman)
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From page 202... ...
2. "Alternative Aluminum Spent Nuclear Fuel Treatment Technology Development Status Report," October 1997, WSRC-TR-9700345(U)
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From page 203... ...
established the Research Reactor Spent Nuclear Fuel Task Team to assist In developing a technical strategy for ~ntenm management and ultimate disposition of the foreign and domestic aluminum-based research reactor spent nuclear fuel In DOE's junsdiction, including both current inventory and expected receipts. The Task Team developed a two-volume report titled Technical Strategy for the Treatment, Packaging, and Disposal of Aluminum-Based Spent Nuclear Fuel [DeVine et al., 19961, issued in June of 1996.
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From page 204... ...
In a subsequent report [Kmpa 1997] , several strategies have been devised that include reprocessing of the current inventory of spent fuel through about 2010 and applying some other treatment process to those fuels that enter the inventory in later years.
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From page 205... ...
Question 2: Are the cost and schedule estimates developed by DOE for the alternative processing options suitable as a basis for comparison and selection of one or more preferred alternatives? Response: Yes and No.
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From page 206... ...
needed to deal with satisfying Nuclear Regulatory Commission reviews and possible licensing of any new facilities or processes. At {east several years would be added to Me schedules outlined in the Task Team report, and extending the period during which the wet basins are needed for storage and handling of spent fuel will also add significantly to the overall project life-cycle cost.
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From page 207... ...
Any technical difficulties in proving out a selected treatment process could result in additional schedule delays. Question 5: Are the cost and schedule estimates for implementing the alternative processing options consistent with DOE procedures anal systems?
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From page 208... ...
The schedule for alternative selection in the Task Team report called for a decision late in 1999. Some winnowing of the alternatives originally recommended for further study has already occurred In that development activities on the press and dilute option have essentially been suspended for lack of funding.
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From page 209... ...
As a result of such premature shutdowns at INEEL and at Hanford, DOE now has a large inventory of residual aluminum-based spent fuel stored at INEEL and a large inventory (about 2,300 tons) of spent metallic uranium fuel from the final years of N-Reactor operation stored at Hanford in wet pools where it is slowly corroding into sludge.
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From page 210... ...
DeVine, I C., et al., Technical Strategy for the Treatment, Packaging, and Disposal of Alum~num-Based Spent Nuclear Fuel, a report of the Research Reactor Spent Nuclear Fuel Task Team.
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