Abstract
Data from a rock drillcore, taken perpendicular to a water-bearing fracture in crystalline rock, clearly indicate water-rock interactions in and around the fracture. Although there is evidence of microfracturing at some distance from the main fracture, and therefore potential advective flow across the entire shear zone, simple calculations indicate that transport of Ra-226 in the vicinity of the main fracture can be described simply by matrix diffusion. This is a useful simplification for safety assessment studies and the consequences to the estimated radionuclide retardation in the vicinity of the fracture are discussed with respect to the probably over-conservative assumptions made in Nagra’s safety assessment model base case.
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References
Nagra: Nagra Gewahr Report series, NGB 85-09, Nagra, Baden, Switzerland, 1985
Foster, S.S.D.: J. Hydrol., 25, 159, 1975
Neretnieks, I.: J. Geophys. Res. 85, 4379, 1980
Smellie, J.A.T., MacKenzie, A.B. and Scott, R.D.: Chem. Geol. 55, 233, 1986
Wadden, M.M. and Katsube, T.J.: Geol.Surv. Canada Rep. 8182-GP2, 1981
Bacon, M.P. and Rosholt, J.N.: Geochim. Cosmochim. Acta 46, 651, 1982
Meyer, J., Mazurek, M. and Alexander, W.R.: in M.H. Bradbury (ed.), PSI Bericht Nr 28, PSI, Villigen, Switzerland, 1989
Nagra: Nagra Technical Report series, NTB 81-07, Nagra, Baden, Switzerland, 1981
McKinley, I.G., Alexander, W.R., Bajo, C, Frick, U., Hadermann, J., Herzog F.A. and Hoehn, E.: Sci. Basis Nucl. Waste Manag. XI, 179, 1988
Alexander, W.R., MacKenzie, A.B., Scott, R.D. and McKinley, I.G.: Nagra Technical Report series, NTB 87-08, Nagra, Baden, Switzerland, 1990
Eyal, J. and Fleischer, R.L.: Geochim. Cosmochim. Acta 49, 1155, 1985
Baeyens, B., Aksoyoglu, S. and Bradbury, M.H.: in M.H. Bradbury (ed)., PSI Bericht Nr 28, PSI, Villigen, Switzerland, 1989
Ames, L.L., McGarrah, J.E. and Walker, B.A.: Clays Clay Min. 31, 343, 1983
Hadermann, J. and Roesel, F.: EIR Bericht Nr 551, PSI, Villigen, Switzerland, 1985
Gascoyne, M. and Schwarcz, H.P.: Chem. Geol. 59, 75, 1986
Vandergraf, T.T.: AECL Report TR-120, Pinawa, Canada, 1982
McKinley, I.G. and Hadermann, J.: Nagra Technical Report series, NTB 84-40, Nagra, Baden, Switzerland, 1985
Skagius, K. and Neretnieks, I.: Sci. Basis Nucl. Waste Manag. V, 509–518, 1982
Hadermann, J. and Jakob, A.: Nagra Technical Report series, NTB 87-07, Nagra, Baden, Switzerland, 1987
Shea, M.: Sci. Basis Nucl. Waste Manag. VII, 1984
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Alexander, W.R., McKinley, I.G., MacKenzie, A.B. et al. Verfication of matrix diffusion by means of natural decay series disequilibria in a profile across a water-conducting fracture in granitic rock. MRS Online Proceedings Library 176, 567 (1989). https://doi.org/10.1557/PROC-176-567
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DOI: https://doi.org/10.1557/PROC-176-567