Aquifer analysis and modeling in a fractured, heterogeneous medium

Journal Article · · Ground Water; (United States)

DOI:https://doi.org/10.1111/j.1745-6584.1992.tb01535.x· OSTI ID:7249017

Lee, R R; Ketelle, R H; Bownds, J M ^[1]; Rizk, T A ^[2]

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1. Oak Ridge National Lab., TN (United States). Energy Div.
2. Tennessee Valley Authority Engineering Lab., Norris, TN (United States)

A ground-water flow and contaminant transport modeling study was performed at a proposed low-level radioactive waste disposal site on the Department of Energy's Oak Ridge Reservation to assess the accuracy of a computer simulation of the flow field in the shallow water-table aquifer. The migration of a ground-water tracer, under controlled field conditions, was used as a comparative benchmark of solute transport simulations assuming different aquifer characteristics. A conventional approach to aquifer analysis and modeling, which assumed the domain to be homogeneous with low anisotropy, resulted in an inaccurate simulation of tracer migration. Alternative conceptual models were formulated which considered the effects of geologic heterogeneities on tracer migration which could be verified by additional data acquisition and analysis. Application of the alternative concepts in numerical modeling resulted in more accurate simulations of tracer migration. These results suggested that local geology created discrete flow pathways oriented oblique to the maximum gradient which were unresolved in conventional aquifer analysis. Results of the study showed that standard approaches to aquifer analysis and computer modeling are crudely representative of the flow field and provide nonconservative estimates of contaminant transport at the scale of a waste disposal unit. By adopting an iterative approach to site characterization, conceptual model formulation, and numerical modeling, the level of resolution provided by a ground-water tracer was accurately simulated.

• OSTI ID: 7249017
• Journal Information: Ground Water; (United States), Journal Name: Ground Water; (United States) Vol. 30:4; ISSN GRWAAP; ISSN 0017-467X
• Country of Publication: United States
• Language: English

Related Subjects

053002* -- Nuclear Fuels-- Environmental Aspects-- Radioactive Effluents-- (1992-)
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
54 ENVIRONMENTAL SCIENCES
540230 -- Environment
Terrestrial-- Radioactive Materials Monitoring & Transport-- (1990-)
ENVIRONMENTAL TRANSPORT
GROUND WATER
HYDROGEN COMPOUNDS
LOW-LEVEL RADIOACTIVE WASTES
MASS TRANSFER
MATERIALS
MATHEMATICAL MODELS
NATIONAL ORGANIZATIONS
OAK RIDGE RESERVATION
OXYGEN COMPOUNDS
POLLUTION
RADIOACTIVE MATERIALS
RADIOACTIVE WASTES
RADIONUCLIDE MIGRATION
US DOE
US ERDA
US ORGANIZATIONS
WASTES
WATER
WATER POLLUTION