Multicomponent mass transport model: a model for simulating migration of radionuclides in ground water

Abstract

PNL-3162 PATHS Groundwater Hydrologic Code-PATHS is a first-level (simplest), idealized, hybrid analytical/numerical code for two-dimensional, saturated groundwater flow and single component transport. The geology of the modeled region must be homogeneous. PNL-3160 VTT (Variable Thickness Transient) Groundwater Hydrologic Code-VTT is a second-level (intermediate complexity) twodimensional saturated groundwater flow code, using the Boussinesq approximation, finite difference approach. It has two-dimensional (quasi three-dimensional) multiaquifer capability. Heterogeneous geology is considered. PNL-2939 FE3DGW (Finite-Element, Three-Dimensional Groundwater) Hydrologic Code-FE3DGW is a third-level (high complexity) three-dimensional, finite-element approach (Galerkin formulation) to solve for saturated groundwater flow. Heterogeneous geology is considered .

Hanford Site National Evnironmental Policy Act (NEPA) characterization

“…MMT has undergone several developmental changes, and documentation exists for both one-dimensional (Washburn et al 1980) and two-dimensional • When velocity distributions are calculatedbefore transport simulation, it is assumed that the advection patterns are not dependent on the chemical composition or temperature of the solution (i.e., momentum, mass, and energy transport processes are…”

Particle-Tracking Technique for Nuclide Decay Chain Transport in Fractured Porous Media

“…( 5) ( 6) As the boundary conditions, a band release for the nuclide release mode at the fracture entrance (x=O) is introduced. The assumptions of band release are< 9 l :…”

Hanford Site National Environmental Policy Act (NEPA) characterization

“…MMT has undergone several developmentalchanges, and documentationexistsfor both one-dimensional (Washburn et al 1980) MMT is a direct simulation type of transport analog adapted from an earlier thermal transport model (Eliasonand Foote 1972). The advantages of using a directsimulation model versus the "model equation" approach include (1) the direct simulationmodel is always mass conservative, (2) there is no cumulativenumerical dispersion,(3) the directsimulationmodel has greater numericalstability, and (4)it facilitatesthe handling of multicomponentsystems.…”