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Creep Analyses of Titanium Drip Shield Subjected to Rockfall Static Loads in the Proposed Geologic Repository at Yucca Mountain

Published online by Cambridge University Press:  21 March 2011

Brett W. Neuberger ,
Charles A. Greene  and
G. Douglas Gute
Brett W. Neuberger
Affiliation:
Division of Waste Management, U.S. Nuclear Regulatory Commission, Mail Stop T-7C6, Washington DC 20555-0001, USA
Charles A. Greene
Affiliation:
Division of Waste Management, U.S. Nuclear Regulatory Commission, Mail Stop T-7C6, Washington DC 20555-0001, USA
G. Douglas Gute
Affiliation:
Center for Nuclear Waste Regulatory Analyses, Southwest Research Institute, 6220 Culebra Rd, San Antonio, TX 78238, USA
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Abstract

The U.S. Department of Energy (DOE) has included a drip shield (DS) as a principle component of the engineered barrier system (EBS) for the proposed high-level nuclear waste geologic repository at Yucca Mountain, Nevada. The current DS design consists of titanium grade 7 (Ti Gr 7) plates and Ti Gr 24 support beams and bulkheads. The intended functions of the DS are to divert dripping water around and prevent rockfall damage to the waste package (WP). Sustained static loading of the DS may occur as a result of rockfall or drift collapse. These static loads may cause residual stress that approaches the yield stresses of the different DS materials. This level of residual stress would enable various creep mechanisms to transpire. A preliminary assessment of the potential for DS creep after a dynamic rock block impact is presented in this paper by expressing the DS residual Von Mises stress levels as fractions of the Ti alloy yield stress (YS). It was determined, using creep data from similar alloys that the residual stress levels within a DS after a 2-tonne rock block impact per DS segment length could cause creep in both the Ti Gr 7 plates and Ti Gr 24 bulkheads and support beams. The results of this study will assist the U.S. Nuclear Regulatory Commission (NRC) in evaluating the risk significance of the expected DS performance characteristics under actual repository conditions.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 713: Symposium JJ – Scientific Basis for Nuclear Waste Management XXV , 2002 , JJ11.7
Copyright
Copyright © Materials Research Society 2002

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References

REFERENCES

1.office of Civilian Radioactive Waste Management, Yucca Mountain Science and Engineering Report, DOE/RW-0539, 2001.Google Scholar
2. Collings, E.W., The Physical Metallurgy of Titanium Alloys, ASM International, 1984.Google Scholar
3. Adenstedt, H., Creep of Titanium at Room Temperature, Metal Progress, Vol. 56, p. 658–660, 1949.Google Scholar
4. Thompson, A.W., Odegard, B.C., The Influence of Microstructure on Low Temperature Creep of Ti-5Al-2.5Sn, Metallurgical Transactions, Vol. 4, p. 899–908, 1973.Google Scholar
5. Odegard, B.C. and Thompson, A.W., Low Temperature Creep of Ti-6Al-4V, Vol. 5, p. 1207–1213, 1974.Google Scholar
6. Miller, W.H. Jr, Chen, R.T., and Starke, E.A. Jr, Microstructure, Creep, and Tensile Deformation in Ti-6Al-2Nb-1Ta-0.8Mo, Metallurgical Transactions A, Vol. 18A, p. 1451–1468, 1987.Google Scholar
7. Hatch, A.J., Partridge, J.M., Broadwell, R.G., Room-Temperature Creep and Fatigue Properties of Titanium Alloys, Journal of Materials, Vol. 2, No. 1, p.111–119, 1967.Google Scholar
8. Chu, H.P., Room Temperature Creep and Stress Relaxation of a Titanium Alloy, Journal of Materials, Vol. 5, No. 3, p. 633–642, 1970.Google Scholar
9. Zeyfang, R., Martin, R., Conrad, H., Low Temperature Creep of Titanium, Materials Science and Engineering, Vol. 8, p. 134–140, 1971.Google Scholar
10. Reimann, W.H., Room Temperature Creep in Ti-6Al-4V, Journal of Materials, JMLSA, Vol. 6, No. 4, p. 926–940, 1971.Google Scholar
11. Imam, M.A. and Gilmore, C.M., Room Temperature Creep of Ti-6Al-4V, Metallurgical Transactions A, Vol. 10A, p. 419–425, 1979.Google Scholar
12. Chadrabarti, A.K. and Nichols, E.S., Titanium '80, Science and Technology, AIME, Warrendale, PA, 1981, p. 1081–1096, 1980.Google Scholar
13. Greene, C.A. and Ankem, S., Ambient Temperature Tensile and Creep Deformation Behavior of Alpha and Beta Titanium Alloys, Beta Titanium Alloys in the 1990's, Edited by Eylon, D., Boyer, R.R., and Koss, D.A., p. 309–319, 1993.Google Scholar
14. Ankem, S., Greene, C.A., Singh, S., Time Dependent Twinning During Ambient Temperature Creep of Alpha Ti-Mn Alloy, Scripta Metallurgica et Materialia, Vol. 30, No. 6, p. 803–808, 1994.Google Scholar
15. Ankem, S., Greene, C.A., Singh, S., Sil, D., Recent Developments in Ambient Temperature Creep Deformation Behavior of Alpha, Alpha-Beta and Beta Titanium Alloys, Microstructure/Property Relationships of Titanium Alloys, Proceeding of the Harold Margolin Symposium, 1994.Google Scholar
16. Greene, C.A., Ankem, S., Singh, S., The Effect of Morphology and Alloying Elements on the Ambient Temperature Creep of Alpha-Beta Titanium Alloys, Titanium '95, Science and Technology, p. 1315–1322, 1995.Google Scholar
17. Ankem, S., Greene, C.A., Aiyangar, A.K., Recent Developments in Growth Kinetics of Deformation Twins in Bulk Metallic Materials, Proceedings of the Symposium on Advances in Twinning, Edited by Ankem, S. and Pande, C.S., TMS, Warrendale, PA, p. 127–143, 1999.Google Scholar
18. Neeraj, T., Hou, D.H., Daehn, G.S., Mills, M.J., Phenomenological and Microstructural Analysis of Room Temperature Creep in Titanium Alloys, Acta Materialia, Vol. 48, p. 1225–1238, 2000.Google Scholar
19. Teper, B., Activities Aimed at Qualification of a HLW Disposal Container, Proceedings of the Second Annual International Conference of High Level Radioactive Waste Management, American Nuclear Society, New York, 1991.Google Scholar
20.American Society for Testing and Materials, Standard Specification for Titanium and Titanium Alloy Strip, Sheet, and Plate, ASTM Designation: B 265–98, 1998.Google Scholar