FRACFLO, 2-D Radionuclide Groundwater Transport in Fracture System

1 - Description of program or function: FRACFLO computes the two- dimensional, space-time-dependent, convective dispersive transport of a single radionuclide in an unbounded single or multiple parallel fracture system with constant aperture. It calculates the one-dimensional diffusive transport into the rock matrix as well as the mass flux and cumulative mass flux at any point in the fracture. Steady-state isothermal ground-water flow and parallel streamlines are assumed in the fracture, and the rock matrix is considered to be fully saturated with immobile water. The model can treat a single or multiple finite patch source or a Gaussian distributed source subject to a step- or band-release mode. 2 - Method of solution: Analytical solutions for the transient advective-dispersive Transport of a single radionuclide through fractures (two-dimensional analysis) and rock (one-dimensional analysis) are based on Laplace and Fourier transformation techniques and a Gauss-Legendre integration scheme. 3 - Restrictions on the complexity of the problem: The flow field is assumed to be semi-infinite in the horizontal direction normal to the source, and of either finite or infinite extent in the vertical direction orthogonal to the source. The initial concentration in both the fracture and the rock is assumed to be zero