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Stochastic Analysis of Groundwater Traveltime for Long-Term Repository Performance Assessment

Published online by Cambridge University Press:  25 February 2011

P.M. Clifton
Affiliation:
Rockwell Hanford Operations, P.O. Box 800, Richland WA 99352
R.G. Baca
Affiliation:
Rockwell Hanford Operations, P.O. Box 800, Richland WA 99352
R.C. Arnett
Affiliation:
Rockwell Hanford Operations, P.O. Box 800, Richland WA 99352
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Abstract

This paper describes a method of stochastically analyzing groundwater traveltime. The method uses a Monte Carlo technique to generate a suite of random spatial fields that are subsequently input to the groundwater flow and groundwater traveltime equations. Stochastic inputs to these equations can be (1) transmissivity (or hydraulic conductivity), (2) effective thickness (or effective porosity), or (3) boundary conditions. In a transient problem, storage coefficient (or specific storage) could also be stochastically treated. Spatial correlation in the random input fields is accounted for by means of a multivariate random-number generator, which requires the first two statistical moments of these fields to be specified. The output from the Monte Carlo analysis is a suite of groundwater traveltime realizations that can be used to derive exceedance probabilities. These probabilities provide a measure of the degree of confidence in meeting set criteria.

A preliminary application of this method using data from the deep basalts beneath the Hanford Site is also presented. The results illustrate how this method can be used to evaluate compliance with a technical criterion relating to groundwater traveltime.

Type
Research Article
Copyright
Copyright © Materials Research Society 1984

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References

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