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Porosities of and Diffusivities in Crystalline Rock and Fissure Coating Materials

Published online by Cambridge University Press:  25 February 2011

Kristina Skagius  and
Ivars Neretnieks
Kristina Skagius
Affiliation:
Department of Chemical EngineeringRoyal Institute of TechnologyS-100 44 STOCKHOLM, Sweden
Ivars Neretnieks
Affiliation:
Department of Chemical EngineeringRoyal Institute of TechnologyS-100 44 STOCKHOLM, Sweden
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Abstract

The diffusion of non-sorbing species in different rock materials and fissure coating materials have been studied. The results show that the effective diffusivity of iodide in granites with fissure coating materials is of the same magnitude or higher as the effective diffusivity for iodide in granites without fissure coating material. Also the porosities of the granites with fissure coating material were higher. The effective diffusivity for iodide in rock materials without fissure coating material was determined to be from 1.i0-14 m2/s to about 7.10-13 m2/s.To simulate the stress that exists in the bedrock at large depths diffusion experiments with iodide in rock materials under mechanical stress, and electrical resistivity measurements in salt-water-saturated rock cores under stress have been started. Electrical resistivity measurements is an indirect method to determine the diffusivity.Results from some initial measurements show that the effective diffusivity is reduced to about 40 % of the value for unstressed samples at pressures of 230-280 bar. This is the expected stress at repository depths.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 26: Symposium D – Scientific Basis for Nuclear Waste Management VII , 1983 , 835
Copyright
Copyright © Materials Research Society 1984

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References

REFERENCES

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