Hostname: page-component-77c89778f8-7drxs Total loading time: 0 Render date: 2024-07-20T05:24:57.239Z Has data issue: false hasContentIssue false

The Importance of Thermal Loading Conditions to Waste Package Performance at Yucca Mountain

Published online by Cambridge University Press:  15 February 2011

Thomas A. Buscheck
Affiliation:
Earth Sciences Division, L–206, Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94551
John J. Nitao
Affiliation:
Earth Sciences Division, L–206, Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94551
Get access

Abstract

Temperature and relative humidity are primary environmental factors affecting waste package corrosion rates for the potential repository in the unsaturated zone at Yucca Mountain, Nevada. Under ambient conditions, the repository environment is quite humid. If relative humidity is low enough (<70%), corrosion will be minimal. Under humid conditions, corrosion is reduced if the temperature is low (<60°C). Using the V-TOUGH code, we model thermo-hydrological flow to investigate the effect of repository heat on temperature and relative humidity in the repository for a wide range of thermal loads. These calculations indicate that repository heat may substantially reduce relative humidity on the waste package, over hundreds of years for low thermal loads and over tens of thousands of years for high thermal loads. Temperatures associated with a given relative humidity decrease with increasing thermal load. Thermal load distributions can be optimized to yield a more uniform reduction in relative humidity during the boiling period.

Type
Research Article
Copyright
Copyright © Materials Research Society 1995

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. Stahl, D., McCoy, J.K., and McCright, R.D., “Impact of Thermal Loading on Waste Package Material Performance,” Material Research Society, Pittsburgh, PA, Proceedings Material Research Society XVIII Symposium on the Scientific Basis for Nuclear Waste Management, Oct. 2327 (1994).Google Scholar
2. Buscheck, T.A., Nitao, J.J., and Saterlie, S.F., “Evaluation of Thermo-Hydrological Performance in Support of the Thermal Loading Systems Study,” American Nuclear Society, La Grange Park, IL, Proceedings Fifth International High-Level Radioactive Waste Management Conference, Las Vegas, NV, May 1994. Also, Lawrence Livermore National Laboratory, Livermore, CA, UCRL–JC–115352 (1994).Google Scholar
3. Buscheck, T.A., and Nitao, J.J., “The Impact of Buoyant Gas-Phase Flow and Heterogeneity on Thermo-Hydrological Behavior at Yucca Mountain,” American Nuclear Society, La Grange Park, IL, Proceedings Fifth International High-Level Radioactive Waste Management Conference, Las Vegas, NV, May 1994. Also, Lawrence Livermore National Laboratory, Livermore, CA, UCRL–JC–115351 (1994).Google Scholar
4. Buscheck, T.A., and Nitao, J.J., “Repository-Heat-Driven Hydrothermal Flow at Yucca Mountain, Part I: Modeling and Analysis,”Nuclear Technology 104 (3), 418448 (1993).Google Scholar
5. Nitao, J.J., “V-TOUGH - An Enhanced Version of the TOUGH Code for the Thermal and Hydrologic Simulation of Large-Scale Problems in Nuclear Waste Isolation,” Lawrence Livermore National Laboratory, Livermore, CA, UCID–21954 (1989).Google Scholar
6. Pruess, K., “TOUGH User℉s Guide,” Nuclear Regulatory Commission, Washington, DC, NUREG/CR-4645 (1987).Google Scholar
7. Buscheck, T.A., Wilder, D.G., and Nitao, J.J., “Repository-Heat-Driven Hydrothermal Flow at Yucca Mountain, Part II: Large-Scale In Situ Heater Tests,” Nuclear Technology 104 (3), 449471 (1993).Google Scholar