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Permeability, Swelling and Radionuclide Retardation Properties of Candidate Backfill Materials*

Published online by Cambridge University Press:  15 February 2011

J. H. Westsik JR.
Affiliation:
Pacific Northwest Laboratory**, P. O. Box 999, Richland, Washington 99352
L. A. Bray
Affiliation:
Pacific Northwest Laboratory**, P. O. Box 999, Richland, Washington 99352
F. N. Hodges
Affiliation:
Pacific Northwest Laboratory**, P. O. Box 999, Richland, Washington 99352
E. J. Wheelwright
Affiliation:
Pacific Northwest Laboratory**, P. O. Box 999, Richland, Washington 99352
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Abstract

A backfill placed between a nuclear waste canister and the host geology of a nuclear waste repository can impede the migration of water through the waste package and retard the movement of radionuclides into the geologic formation. Hydraulic conductivities and swelling pressures are being determined as functions of the density of the compacted backfill, temperature, radiation dose, hydraulic head and the chemical composition of the permeating fluid. Bentonite clays and bentonite/sand mixtures have received initial emphasis. Sodium bentonite and calcium bentonite samples compacted to a dry density of 2.1 g/cm3 had hydraulic conductivities in the range of 10−12 to 10−13 cm/s. In addition, batch distribution ratios (Rd) for Sr, Cs, Am, Np, I, U and Tc have been measured for a number of candidatebackfill materials. Both initial permeability and sorption studies have used a synthetic basaltic ground water.

Type
Research Article
Copyright
Copyright © Materials Research Society 1982

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Footnotes

**

Operated for the U. S. Department of Energy by Battelle Memorial Institute.

*

Work performed for the U. S. Department of Energy under Contract DE-AC06-76RLO 1830.

References

REFERENCES

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