7. UNUSUAL FEATURES OF THE PROGRAM
Options are available which permit simulation of any one of the individual processes or coupled combinations of the processes. A special option is available to treat steady-state fluid flow with transient radionuclide transport. SWENT offers a wide choice in the specification of boundary conditions.
To provide control of numerical diffusion and overshoot or undershoot, the model permits the choice of backward or central difference approximations in the time-integration scheme and in the convective terms of the transport processes. Either direct or iterative techniques may be selected for the solution of matrix equations, as appropriate, from considerations of storage and time requirements.
The three-dimensional simulation capability of the model can be adapted to a simulation of the fractured medium in one and two dimensions. The capability to link SWENT to PABLM (NESC Abstract 926), a dose-to-man code, is incorporated.
The program can be used in a wide variety of ground-water applications. When operated sequentially with PABLM it can be used to address the complete assessment of the site subsystem, and since it models coupled processes, it is suitable for various repository assessments.