Hostname: page-component-f554764f5-c4bhq Total loading time: 0 Render date: 2025-04-17T06:11:30.302Z Has data issue: false hasContentIssue false
  • English
  • Français

Radioisotope Fractionation and Secular Disequilibrium in Performance Assessment for Geologic Disposal of Nuclear Waste

Published online by Cambridge University Press:  21 March 2011

William M. Murphy  and
David A. Pickett
William M. Murphy
Affiliation:
Department of Geosciences, California State University, Chico, CA 95929-0205
David A. Pickett
Affiliation:
Center for Nuclear Waste Regulatory Analyses (CNWRA), Southwest Research Institute, San Antonio, TX 78238-5166
Get access

Abstract

Two potential applications of radioisotope fractionation and decay-series secular disequilibrium in performance assessment for geologic repositories for nuclear waste are preferential radionuclide release in source term analysis and characterization of system closure as a measure of the capacity of the geologic system to isolate waste. A primary mechanism of radioisotope fractionation is selective release and mobility of alpha decay products because of nuclear recoil effects, which is evident in natural system data. Preferential release of radioisotopes from nuclear waste forms or solubility limiting solid phases could affect repository performance; however, consequences of differential radioisotope releases are neglected in performance assessments. Decay-series disequilibria are useful also to characterize open/closedsystem behavior in natural systems. Systems that are closed on time scales that are long relative to the half-lives of decay chain nuclides achieve secular equilibrium characterized by unit activity ratios among series nuclides. For geologic disposal of nuclear waste, measures focused on chemical system closure could capture the essential characteristics of the natural system with respect to radionuclide isolation and could be based quantitatively on uranium and thorium decay series secular equilibria/disequilibria.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 713: Symposium JJ – Scientific Basis for Nuclear Waste Management XXV , 2002 , JJ8.7
Copyright
Copyright © Materials Research Society 2002

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable

References

REFERENCES

1. Osmond, J.K. and Cowart, J.B., Atom. Ener. Rev. 14, 621 (1976).Google Scholar
2. Murphy, W.M. and Pickett, D.A., in Geotrap 5 Proceedings, (OECD/Nuclear Energy Agency, Paris, in press, 2001).Google Scholar
3. Duerden, P. editor, International Intraval Project Phase 1, Case 8, The Alligator Rivers Natural Analogue. (Swedish Nuclear Power Inspectorate and OECD/Nuclear Energy Agency, Paris, 1992).Google Scholar
4. Gascoyne, M. and Miller, N.H., in Proceedings of the 9th International High-Level Radioactive Waste Management Conference, (American Nuclear Society, La Grange Park, Ill., 2001), CD-ROM file 06_04.pdf.Google Scholar
5. Ildefonse, P. Muller, J.-P., Clozel, B. and Calas, G. Eng. Geol. 29, 413 (1990).Google Scholar
6. Murphy, W.M. and Pearcy, E.C., in Scientific Basis for Nuclear Waste Management XV, edited by Sombret, C.G., (Mat. Res. Soc. Proc. 257, Pittsburgh, PA, 1992) pp. 521–527.Google Scholar
7. Pearcy, E.C., Prikryl, J.D., Murphy, W.M., and Leslie, B.W., Appl. Geochem. 9, 713 (1994).Google Scholar
8. Pearcy, E.C., Prikryl, J.D., and Leslie, B.W., Appl. Geochem. 10, 685 (1995).Google Scholar
9. Prikryl, J.D., Pickett, D.A., Murphy, W.M., and Pearcy, E.C., J. Contam. Hydrol. 26, 61 (1997).Google Scholar
10. CRWMS M&O, Natural Analogues for the Unsaturated Zone, ANL-NBS-HS-000007 REV 00 (Civilian Radioactive Waste Management System Management and Operating Contractor, Las Vegas, NV, 2000).Google Scholar
11. CRWMS M&O, Natural-Analogue Investigations in Support of Performance Assessment of the Potential Yucca Mountain Radioactive-Waste Repository, TDR-WIS-PA-000001 REV 00 ICN 01 (Civilian Radioactive Waste Management System Management and Operating Contractor, Las Vegas, NV, 2000), Appendix C.Google Scholar
12. Pickett, D.A. and Murphy, W.M., in Eighth EC Natural Analogue Working Group Meeting Proceedings (European Commission, Luxembourg, in press, 2001).Google Scholar
13. Pickett, D.A. and Murphy, W.M., in Scientific Basis for Nuclear Waste Management XXII, edited by Wronkiewicz, D.J. and Lee, J.H. (Mat. Res. Soc. Proc. 556, Warrendale, PA, 1999) pp. 809–816.Google Scholar
14. Pickett, D.A., Murphy, W.M., and Leslie, B.W., in 8th International Conference on the Behaviour of Actinides and Fission Products in the Geosphere. Migration '01. Abstracts (Bregenz, Austria, September, 2001) p. 103.Google Scholar
15. CNWRA, Total-System Performance Assessment (TPA) Version 4.0 Code: Module Descriptions and User's Guide, (Center for Nuclear Waste Regulatory Analyses, San Antonio, TX, 2000).Google Scholar
16. CRWMS M&O, Total System Performance Assessment for Site Recommendation, TDRWIS-PA-000001 REV 00 ICN 01 (Civilian Radioactive Waste Management System Management and Operating Contractor, Las Vegas, NV, 2001).Google Scholar
17. Eyal, Y. and Ewing, R.C., in Proceedings 1993 International Conference on Nuclear Waste Management and Environmental Remediation, (American Society of Mechanical Engineering, New York, 1993) pp. 191–196.Google Scholar
18. Weber, W.J. and Ewing, R.C., in Scientific Basis for Nuclear Waster Mannagement XXV, edited by McGrail, B.P. and Cragnolino, G.A. (this volume).Google Scholar
19. Bibler, N.E., Fellinger, T.L., Crawford, C.L., and Schumacher, R.F., in Scientific Basis for Nuclear Waster Mannagement XXV, edited by McGrail, B.P. and Cragnolino, G.A. (this volume).Google Scholar
20. CRWMS M&O, Miscellaneous Waste-Form FEPs, ANL-WIS-MD-000009 REV 00 ICN 01, (Civilian Radioactive Waste Management System Management and Operating Contractor, Las Vegas, NV, 2000).Google Scholar
21. BSC, FY 01 Supplemental Science and Performance Analyses, TDR-MGR-MD-000007 REV 00, (Bechtel SAIC Company, LLC, Las Vegas, NV, 2001).Google Scholar
22. Kaplan, P. Klavetter, E. and Peters, R. Approaches to Groundwater Travel Time, Sand88-2868C (Sandia National Laboratories, Albuquerque, NM, 1989).Google Scholar
23. Davies, P.B., Pickens, J.F., and Hunter, R.L., Complexity in the Validation of Ground-water Travel Time in Fractured Flow and Transport Systems, Sand89-2379 (Sandia National Laboratories, Albuquerque, NM, 1991).Google Scholar