Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-29T09:52:20.775Z Has data issue: false hasContentIssue false
  • English
  • Français

Key Issues Influencing the Performance of Near-Field Barriers

Published online by Cambridge University Press:  01 January 1992

P.W. Tasker ,
S.J. Wisbey  and
C.B. Boyle
P.W. Tasker
Affiliation:
AEA Decommissioning & Radwaste, Harwell Laboratory, Didcot, Oxon., OXI1 ORA, UK
S.J. Wisbey
Affiliation:
AEA Decommissioning & Radwaste, Harwell Laboratory, Didcot, Oxon., OXI1 ORA, UK
C.B. Boyle
Affiliation:
AEA Decommissioning & Radwaste, Harwell Laboratory, Didcot, Oxon., OXI1 ORA, UK
Get access

Abstract

In developing a national strategy for the disposal of radioactive wastes, each country will consider isolation options that are appropriate to the types of waste that are produced. The options are developed in response to specific national regulatory requirements, and thus will focus on different aspects of performance. However, there are a number of technical concerns that are common to all programmes. The major issues concerning the behaviour of the chemical and physical barriers in the near field of a radioactive waste repository are discussed in this paper.

The description of key issues has been divided into the following categories: barrier design, barrier evolution, scientific understanding through modelling, and validation of performance. The near-field barriers are selected and designed to provide appropriate radionuclide containment and control. Factors affecting the evolution of these barriers, such as container degradation and gas generation, determine the subsequent release of radionuclides to the human environment. Modelling repository evolution is therefore an integral feature of performance assessments, and issues such as the treatment of inhomogeneities and non-equilibrium chemistry may need to be addressed. However, the use of mathematical and computer models implies a requirement for validation. The use of demonstration experiments and natural analogues builds confidence in the predictions of repository performance models, and provides a degree of validation for otherwise inaccessible timescales.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 294: Symposium V – Scientific Basis for Nuclear Waste Management XVI , 1992 , 697
Copyright
Copyright © Materials Research Society 1993

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.)

References

REFERENCES

1.NEA/IAEA/CEC, “Disposal of Radioactive Waste: Can Long-term Safety be Evaluated? An International Collective Opinion”, OECD, Paris (1991).Google Scholar
2.IAEA, “Radioactive Waste Management Glossary”, IAEA-TECDOC-447 (1988).Google Scholar
3. Greenfield, B.F., Spindler, M.W. and Woodwark, D.R. “Summary of the Effects of Organic Degradation Products on Near-field Radionuclide Chemistry”, UK Nirex Ltd. Report, NSS/R298 (In preparation), (1992).Google Scholar
4. Ramsay, J.D.F., Walters, W.S. and Nicholson, S., “Experimental Studies of Radionuclide Transport by Colloidal Species”, UK Nirex Ltd. Report, NSS/R232 (In preparation), (1992).Google Scholar
5. Bums, W.G., Henshaw, J. and Walters, W.S., “Radiolysis Effects in Repositories”, UK Nirex Ltd. Report, NSS/R191 (In preparation), (1992).Google Scholar
6. Cross, J.E. and Ewart, F.T., “HATCHES-A Thermodynamic Database and Management System”, UK Nirex Ltd. Report, NSS/R212 (1990).Google Scholar
7. Haworth, A., Brown, P.L., Sharland, S.M. and Tweed, C.J., “HARPHRQ-An Extended Version of the Geochemical Code PHREEQE”, UK Nirex Ltd. Report, NSS/R188 (1991).Google Scholar
8. Parkhurst, D.L., Thorstenson, D.C. and Plummer, L.N., U.S. GEOLOGICAL, Survey, Water-Resources Investigations, 80–96 (1985).Google Scholar
9. Haworth, A., Sharland, S.M., Tasker, P.W. and Tweed, C.J., “A Guide to the Coupled Chemical Equilibria and Migration Code CHEQMATE”, UK Nirex Ltd. Report, NSS/Rl113 (1988).Google Scholar
10. Ewart, F.T., Haworth, A. and Wisbey, S.J., “On the Derivation of a Sorption Data Base”, UK Nirex Ltd. Report, NSS/R270 (In preparation), (1992).Google Scholar
11. Agg, P.J. and Sumner, P.J., “Modelling of Gas Generation in Radioactive Waste Repositories”, Proceedings of a Workshop on Gas Generation and Release from Radioactive Waste Repositories (Aix-en-Provence, 1991) pp. 188–199., OECD Paris (1992).Google Scholar
12. Windsor, M.E., “STRAW: A Source-term Code for Burial of Radioactive Waste”, UK Nirex Ltd. Report, NSS/R158 (1989).Google Scholar
13. Jackson, C.P., Lever, D.A. and Sumner, P.J., “Validation of Transport Models for Use in Repository Performance Assessments: A View Illustrated for INTRAVAL Test Case lb.”, UK Nirex Ltd. Report, NSS/R259 (1991).Google Scholar
14. Biddle, P., Gale, M.D., Godfrey, J.G. and Woodwark, D.R., “Equilibrium Leach Testing of Low Level Waste - Part I - Effect of Backfill”, UK Nirex Ltd. Report, NSS/R130 (1989).Google Scholar
15. Alexander, R. (ed.), Jordan Analogue, First Year Report, NAGRA Report NTB-91-10 (In preparation), (1992).Google Scholar
16. National Radiological Protection Board, “Board Statement on Radiological Protection Objectives for the Land-based Disposal of Solid Radioactive Wastes”, Documents of the NRPB, Volume 3, No. 3 (1992).Google Scholar