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Fundamental
understanding of coupled hydro-mechanical processes in a single
fracture.
The
relationship between flow and stress across a fracture with
variable apertures was studied at a time when the prevailing
conceptual model for a fracture was a pair of parallel plates
(Journal references 17, 18, 20).
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Flow
channeling in fractured rocks.
The
concept, which I first discussed over ten years ago and studied
in a series of papers, that flow is limited to a few least resistive
flow paths in a heterogeneous fracture formation has now become
very well accepted in the research community. (Journal
references 22, 24-25, 29, 32-34).
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Stochastic
modeling of tracer tests in heterogeneous media.
I
have developed a 3D stochastic hydrological model which has
the characteristics of both the continuum and discrete fractures,
which are traditionally two conceptual extremes. I have also
developed methodology to quantify the uncertainty in predictive
modeling. (Journal references 26,
36-39).
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Modeling
of thermohydrological processes related to High Level Nuclear
Waste Repository.
The
study of the coupled processes (Journal
references 23, 27, 28, 50). has since been extended to field
measurements (in situ thermal tests) at Yucca Mountain. Significant
advances have been made in the iterative approach of close integration
of measurements and numerical modeling (Journal
references 42, 45, 46, 48, 49).
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Transient
flow and transport of radon into house basements.
Contrary
to prevailing understanding that radon transport was controlled
only by steady state flow, I demonstrated by numerical modeling
(Journal references 30, 35) the
importance of transient flow and transport processes for radon
entry into house basements. The modeled results were since verified
by field observations.
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Application
of fundamental understanding of transport processes to the safety
analysis for WIPP (Waste isolation Pilot Project).Tracer recovery
test results are subject to non-unique interpretation, which
constitute a great challenge in the site characterization effort
for the safety analysis of the WIPP site. The key question is
to ascertain the presence or absence of the retardation mechanism
by diffusion into the rock matrix. Based on analysis of field
tracer test results and numerical modeling, I conclusively demonstrated
that matrix diffusion must be in operation for the transport
in Culebra Dolomite at the WIPP site.
