1
Introduction
In the fall of 1998, the Committee on Electrometallurgical Techniques for DOE Spent Fuel Treatment entered its last year as an operating body. The committee, appointed by the National Research Council (NRC), has functioned since January 1995 to evaluate Argonne National Laboratory 's (ANL's) spent fuel demonstration project for the Department of Energy. Over this period, the committee has released eight reports detailing various aspects of the demonstration project as it has proceeded. The present report is the ninth in this series and will be followed by a tenth, and final, report to be released following the completion of ANL's demonstration project.
This ninth report, as with the preceding eight reports, is a result of a request to the NRC made by the U.S. Department of Energy's Office of Nuclear Energy, Science, and Technology (DOE-NE). As a result, the committee's evaluation of ANL's demonstration project, including its findings and recommendations, is a response to this request. This report is technical in nature and contains abbreviations and acronyms related to the demonstration project, although the report is available to the public. For clarity, a list of abbreviations and acronyms is included in Appendix F. References to previous committee reports are noted in the report.
The committee has operated in three phases, each of which had a different charge. The charges to the committee for Phases 1 and 2 of its work are given in Appendix A. Phase 3, which began in 1998 and will continue through 1999, has three parts to the committee's charge:
-
Continue its ongoing evaluation of ANL's demonstration project, and issue a final report at the end of the demonstration;
-
Review the viability of electrometallurgical technology in light of technical progress in other possible treatment technologies; and
-
Evaluate the criteria developed by ANL and DOE to determine the success of the demonstration project.
The committee in its seventh report1 addressed the second and third aspects of its charge. The committee 's eighth report,2 the present report, and the committee's final report all have addressed and will address the first aspect of the committee's charge for phase 3.
As the committee began its final year, representatives from DOE and the National Research Council discussed plans for reports for the committee's final year of operation. In addition to a status report on the demonstration project (which addressed the first part of the committee's charge for phase 3) and a final report covering all aspects of this project (scheduled for release in late 1999), the DOE requested that the committee produce a report addressing aspects of waste form testing and evaluation as they relate to
|
1 |
National Research Council, Electrometallurgical Techniques for DOE Spent Fuel Treatment: Spring 1998 Status Report on Argonne National Laboratory's R&D Activity, National Academy Press, Washington, D.C., 1998. |
|
2 |
National Research Council, Electrometallurgical Techniques for DOE Spent Fuel Treatment: Status Report on Argonne National Laboratory's R&D Activity as of Fall 1998, National Academy Press, Washington, D.C., 1999. |
ANL's demonstration. The committee's previous report3 was focused on the chemical and electrometallurgical process steps of electrometallurgical technology (EMT) and on ANL's progress in the EBR-II demonstration project. The committee stated in that report that it would defer the part of its charge involving assessment of the waste forms being developed by ANL for disposition of the products of the EMT treatment. This report addresses that aspect of the committee 's overall charge. Over the course of the committee's existence, it has from time to time discussed waste form issues in its reports. The present report discusses these waste forms issues as they relate to the completion of the demonstration project, as well as postdemonstration testing that will be necessary for placement of these waste forms in a geologic repository.
ANL has developed a waste qualification program for its EMT demonstration project that is patterned after the protocols used for the waste qualification of Defense Program high-level waste (DHLW) borosilicate glass.4 The early phases of waste-form acceptance modeling and data collection activities by the EMT program are being conducted to provide quality assurance characterization data during a demonstration project for the EMT process. To support a final waste-acceptance decision, however, major qualification/characterization activities will be necessary beyond the end of the demonstration project.
ANL's demonstration project for the electrometallurgical treatment of SNF produces two waste forms: a metallic waste form (MWF) and a ceramic waste form (CWF). In addition to these two waste forms, a third product stream, metallic uranium, is produced by EMT. At the present time, DOE has made no decisions about the disposition of this material, and it is the committee's understanding that there are no plans for disposing of it as a waste. Consequently, the committee has not attempted to evaluate the suitability of the uranium product as a possible waste form.
PRIOR COMMITTEE FINDINGS AND RECOMMENDATIONS ON WASTE FORMS
From its inception, the committee has produced recommendations regarding these waste forms. In a preliminary assessment report,5 the committee noted that ANL was conducting research and development on both the CWF and the MWF. The qualification of the forms would be conducted in accordance with a waste form qualification plan to be issued in fiscal year 1995.
In its first report,6 the committee noted:
|
3 |
National Research Council, Electrometallurgical Techniques for DOE Spent Fuel Treatment: Status Report on Argonne National Laboratory's R&D Activity as of Fall 1998, National Academy Press, Washington, D.C., 1999. |
|
4 |
DWPF Waste Acceptance Reference Manual (U), WSRC-IM-93-45, Westinghouse Savannah River Company, Savannah River Site, Aiken, SC, 1993. |
|
5 |
National Research Council, A Preliminary Assessment of the Promise of Continued R&D into an Electrometallurgical Approach for Treating DOE Spent Fuel, National Academy Press, Washington, D.C., 1995. |
|
6 |
National Research Council, An Assessment of Continued R&D into an Electrometallurgical Approach for Treating DOE Spent Nuclear Fuel, National Academy Press, Washington, D.C., 1995, p. 39. |
The electrometallurgical technology would generate new waste forms. The fate of the cladding-metal waste form is a major open question, and qualifying the zeolite waste form for burial could present major challenges.
In the July 1996 report,7 the committee concluded:
Greater priority should be given to the development of a strategy and a relevant test protocol to demonstrate acceptability of waste forms. This activity is of the highest importance relative to all other aspects in the development of the electrometallurgical techniques for weapons plutonium disposition.
As a result, the following recommendations were made:
A schedule should be developed and implemented for demonstrating waste form performance over a time period commensurate with DOE' s plans for treatment of spent nuclear fuel and conversion of weapons plutonium to a form suitable for ultimate disposal. Evaluation of waste form performance is of equal concern for application of the electrometallurgical techniques to treatment of DOE spent nuclear fuel, although the latter application is governed by a different schedule.
Waste-form testing should be conducted on the “as-produced” zeolite host phase for radionuclides, as well as on the glass-bonded zeolite waste form.
Continued concern about DOE's acceptability of the waste forms as qualified by the ANL R&D program led to the following recommendations in the status report of the committee in 1996:8
The committee recommends that ANL's ongoing studies be extended to include efforts aimed at defining the phase changes in the salt-loaded zeolite during hot isostatic pressing and determining the fate of the salt, which would no longer be as well isolated from the environment.
The committee recommends that attention be given to establishing the performance of both the zeolite and metal waste forms under conditions relevant to their disposal in a geological repository.
The committee recommends that the several aspects of ANL's substantial effort in waste form development be integrated into a formal, comprehensive program plan.
|
7 |
National Research Council, An Evaluation of the Electrometallurgical Approach for Treatment of Excess Weapons Plutonium, National Academy Press, Washington, D.C., 1996, pp. 28-31. |
|
8 |
National Research Council, Electrometallurgical Techniques for DOE Spent Fuel Treatment: A Status Report on Argonne National Laboratory's R&D Activity, National Academy Press, Washington, D.C., 1996, pp. 8-9. |
Overall concerns about the fate of the waste forms after the end of the demonstration project were described in 1997:9
The planned development schedule for waste forms pushes strategically important parts of the work beyond the end of the demonstration programs; the effect of such delays on the research schedules needs to be carefully evaluated by ANL and DOE. ANL should develop and implement immediately an overall strategic plan that defines the following:
-
the planned state of waste form development at the end of the demonstration phase and the objectives that will remain to be addressed; and
-
the methods for ensuring optimal, synergistic use of all ANL resources for ceramic waste form development and evaluation.
The recommendation for an overall plan for acceptance criteria for the waste forms, agreed upon by DOE and ANL, was repeated in report 6 (1997).10 In report 7 (1998)11 the recommendation and finding were as follows:
Confirmation that the waste forms produced by EMT are acceptable within the DOE's Office of Radioactive Waste (DOE-RW) Office of Civilian Radioactive Waste Management (OCRWM) program for final geological disposal must be a key component in a full qualification of the EMT process.
The committee finds that the criteria established by DOE are reasonable for judging the success of the EBR-II spent fuel treatment demonstration.
The issue of final disposition of the waste forms produced by the electrometallurgical process is essential to determining the usability of this process for the treatment of SNF. The present report reviews the waste forms produced by this process and examines this subject in light of DOE requirements for acceptability of waste forms for placement in a geologic repository.
|
9 |
National Research Council, Electrometallurgical Techniques for DOE Spent Fuel Treatment: Fall 1996 Status Report on Argonne National Laboratory's R&D Activity, National Academy Press, Washington, D.C., 1997, p. 11. |
|
10 |
National Research Council, Electrometallurgical Techniques for DOE Spent Fuel Treatment: Status Report on Argonne National Laboratory's R&D Activity Through Spring 1997, National Academy Press, Washington, D.C., 1997, p. 10. |
|
11 |
Electrometallurgical Techniques for DOE Spent Fuel Treatment: Spring 1998 Status Report on Argonne National Laboratory's R&D Activity, National Academy Press, Washington, D.C., 1998, pp. 24-25. |
