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Excavation Disturbed Zone: Assessment of Its Hydraulic Properties Based on Surface Investigations

Published online by Cambridge University Press:  10 February 2011

S. Vomvoris ,
P. Blomling ,
G. W. Lanyon  and
C. R. Watson
S. Vomvoris
Affiliation:
Nagra, Swiss National Cooperative for the Disposal of Radioactive Waste, Hardstrasse 73, CH-5430 Wettingen, Switzerland, vomvoris@nagra.ch
P. Blomling
Affiliation:
Nagra, Swiss National Cooperative for the Disposal of Radioactive Waste, Hardstrasse 73, CH-5430 Wettingen, Switzerland
G. W. Lanyon
Affiliation:
GeoScience Ltd, The Falmouth Business Park, Bickland Water Road, FALMOUTH Cornwall TR11 4SZ, United Kingdom
C. R. Watson
Affiliation:
GeoScience Ltd, The Falmouth Business Park, Bickland Water Road, FALMOUTH Cornwall TR11 4SZ, United Kingdom
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Abstract

The approach followed by Nagra for the assessment of the hydraulic properties of the excavation disturbed zone (EDZ) around a potential future underground repository site for low-level and medium-level short-lived radioactive wastes is presented. In the approach particular emphasis was placed on assessing, under realistic-conservative assumptions1, an appropriate way to represent the EDZ within the context of performance assessment (PA). Calculated stress changes due to the openings were mapped onto changes of the mechanical aperture of the rock fractures. The resulting changes of hydraulic properties of the EDZ were then computed, with analytical (simple, continuum-type approximation) and numerical (fracture network representation) methods. The results of both computations were used as the basis to: i) provide hydraulic properties for the EDZ used in PA models; ii) assess whether these properties are conservative, i.e., higher values than expected, or not.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 506: Symposium – Scientific Basis for Nuclear Waste Management XXI , 1997 , 873
Copyright
Copyright © Materials Research Society 1998

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References

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