Hostname: page-component-77c89778f8-n9wrp Total loading time: 0 Render date: 2024-07-17T04:13:39.563Z Has data issue: false hasContentIssue false

Direct Determination of Transport Parameters in Repository Materials

Published online by Cambridge University Press:  01 January 1992

J. L. Conca
Affiliation:
Washington State University Tri-Cities, Richland, WA 99352
M.J. Apted
Affiliation:
Intera Sciences, 3609 South Wadsworth Blvd., Denver, CO 80235
R.C. Arthur
Affiliation:
Intera Sciences, 3609 South Wadsworth Blvd., Denver, CO 80235
Get access

Abstract

A new flow technology has been developed that significantly decreases the time required to obtain transport data on saturated and unsaturated porous/fractured media. This technique is based on open-flow centrifugation and was developed to measure steady-state transport properties in most geologic materials within a matter of hours. Centripetal acceleration does not induce artificial effects in samples i.e., fracturing, collapse of interlayer structures, structural dewatering, compaction, chemical changes, etc., that occur with high-pressure methods. Using this technique, hydraulic conductivities (K) and diffusion coefficients (D) for compacted bentonite and four host rocks have been measured and re-interpreted. Based on these new data, K for compacted bentonite is less than 10−14 m/s, a factor of 1000 lower than previous pressure-gradient measurements, providing further assurance that radionuclide transport through bentonite backfill will be diffusion limited. Measured K for mudstone (1.8 × 10−12 m/s) indicates diffusion-limited far-field transport, while advective transport should occur for granite, basalt, and tuff, with expected matrix diffusion coefficients (correlated to measured D values) of 8.3 × 10−13 and 2.5 × 10−12 m2/s for fractured granite and basalt, respectively.

Type
Research Article
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] Pusch, R., Ranhagen, L., and Nilsson., K., Gas Migration through MX-80 Bentonite, Nagra NTB Technical Report 85–36, Nagra, Baden (1985).Google Scholar
[2] T. Pigford and P. Chambrd in Scientific Basis for Nuclear Waste Management XI, edited by M. Apted and R. Westerman (Mater. Res. Soc., Pittsburgh, PA, 1988), pp. 125141.Google Scholar
[3] Conca, J. L. and Wright, J. V., Water Resources Research 26, 1055 (1990).Google Scholar
[4] Nitao, J.J., Buscheck, T.A. and Chesnut, D.A., in Third Annual International Conference on High-Level Radioactive Waste Management ; Vol. 1 (American Nuclear Society, La Grange Park, IL, 1992) 279.Google Scholar
[5] Conca, J.L., Apted, M.J. and Arthur, R.C., this volume.Google Scholar
[6] Arthur, R.C., Apted, M.J. and Conca, J.L., this volume.Google Scholar
[7] Nimmo, J.R., Ribin, J., and Hammermeister, D., Water Resour. Res., 23, 124 (1987).Google Scholar
[8] Conca, J. and Wright, J., in Scientific Basis for Nuclear Waste Management XIV, edited by M. Apted and R. Westerman (Mater. Res. Soc., Pittsburgh, PA, 1991) pp. 879884.Google Scholar
[9] Nimmo, J.R. and Akstin, K.C., Soil Sci. Soc. Am. Jour., 52, 303 (1988).Google Scholar
[10] Pusch, R., Permeability of Highly Compacted Bentonite. SKBF/KBS Technical Report 80–16, Swedish Nuclear Fuel and Waste Management Company, Stockholm (1980).Google Scholar
[11] Neretnieks, I., Some Aspects of the Use of Iron Canisters in Deep Lying Repositories for Nuclear Waste. Nagra NTB Technical Report 85–35, Nagra, Baden (1985).Google Scholar
[12] Dixon, D.A., Ranjan, R.S. and Graham, J., 48th Canadian Geotechnical Society Meeting, Toronto, Ontario (1992).Google Scholar
[13] Park, P.K., Kester, D. R., Duedall, I. W., and Ketchum, B. H., Wastes in the Ocean. Volume 3. (John Wiley & Sons, New York, 1983).Google Scholar
[14] Chapman, N. A. and McKinley, I., The Geological Disposal of Nuclear Waste. (John Wiley & Sons, New York, 1987).Google Scholar
[15] Roxburgh, I. S., Geology of High-Level Nuclear Waste Disposal: An Introduction. (Chapman and Hall, London/ New York, 1987).Google Scholar
[16] Swedish Nuclear Fuel and Waste Management Company, SKB-91, Stockholm (1992).Google Scholar
[17] Neretnieks, I., J. Geophys. Res., 85, 4379 (1980).Google Scholar
[18] Alexander, W.R. and McKinley, I.G., in Fourth Natural Analogue Working Group Meeting (Commis. Europ. Communit. EUR-13014EN, Brussels, 1991) pp. 119151..Google Scholar