Modeling heterogeneous unsaturated flow systems
- Center for Nuclear Waste Regulatory Analyses, San Antonio, TX (United States)
To adequately model large-scale flow and radionuclide transport in naturally heterogeneous unsaturated rock formations, the inherently three-dimensional spatial variability, stratification, and fracturation of porous geologic media must be accounted for. In particular, it is now increasingly recognized that accurate modeling of radionuclide transport over large space-time scales depends on an adequate representation, in the simulated flow system, of a hierarchy of natural heterogeneities and/or fractures of many sizes and shapes. Moreover, in the case of unsaturated flow, the spatial features of geologic media must be represented through nonlinear matrix/fracture hydrodynamic properties. In what follows, some possible approaches towards realistic large-scale unsaturated flow modeling will be discussed, and some initial results and analyses will be presented. We focus here on the solution of the flow problem as a prerequisite to reliable solute transport simulation. To summarize, one of the main difficulties in large-scale subsurface modeling of flow and transport is the existence of a complex three-dimensional hierarchy of natural geologic heterogeneities. Moreover, in the case of partially saturated or unsaturated flow, this difficulty is compounded by the nonlinear nature of the governing equations owing to the nonlinear pressure-dependence of water retention and hydraulic conductivity.
- Research Organization:
- US Nuclear Regulatory Commission (NRC), Washington, DC (United States). Div. of Regulatory Applications; Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses; Arizona Univ., Tucson, AZ (United States). Dept. of Hydrology and Water Resources
- OSTI ID:
- 139517
- Report Number(s):
- NUREG/CP-0040; CONF-9101106-; ON: TI93016989; TRN: 94:007181
- Resource Relation:
- Conference: 5. flow and transport through unsaturated fractured rock related to high-level radioactive waste disposal, Tucson, AZ (United States), 7-10 Jan 1991; Other Information: PBD: Jun 1993; Related Information: Is Part Of Proceedings of workshop 5: Flow and transport through unsaturated fractured rock -- related to high-level radioactive waste disposal; Evans, D.D. [ed.] [Arizona Univ., Tucson, AZ (United States). Dept. of Hydrology and Water Resources]; Nicholson, T.J. [ed.] [Nuclear Regulatory Commission, Washington, DC (United States). Div. of Regulatory Applications]; PB: 238 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
The Influence of Repository Thermal Load on Multiphase Flow and Heat Transfer in the Unsaturated Zone of Yucca Mountain
Nonlinear dynamics in flow through unsaturated fractured-porous media: Status and perspectives