RSICC CODE PACKAGE CCC-686

1. NAME AND TITLE

SWIFT2: Code System to Calculate Waste-Isolation Flow & Transport.

2. CONTRIBUTORS

Sandia National Laboratories, Albuquerque, NM, through the Energy Science and Technology Software Center, Oak Ridge, Tennessee.

3. CODING LANGUAGE AND COMPUTER

Fortran 77; DEC VAX and Fortran IV; CDC Cyber 180 (C00686MNYCP00).

4. NATURE OF PROBLEM SOLVED

SWIFT2 (Sandia Waste Isolation Flow and Transport) is a fully transient, three-dimensional code that solves the coupled equations for transport in geologic media. The processes considered are fluid flow, heat transport, brine migration, and radionuclide-chain transport. Flow, heat and brine transport are coupled via fluid density, fluid viscosity, and porosity. Together they provide the velocity field on which the radionuclide transport depends. Both porous and fractured media are considered. SWIFT2 was developed for use in the analysis of deep geologic nuclear waste-disposal facilities. However, it may be used in other areas such as waste injection into saline aquifers and heat storage in aquifers. Both dual-porosity and discrete-fracture conceptualizations may be considered for the fractured zones. A variable density is included throughout, and a variety of options are available to facilitate the various uses of the code.

5. METHOD OF SOLUTION

Finite differencing is used to discretize the partial differential equations in space and time. The user may choose second-order correct central or first-order correct backward spatial differencing. The matrix equations may be solved iteratively (two-line successive over-relaxation) or directly (matrix banding and Gaussian elimination).

6. RESTRICTIONS OR LIMITATIONS

Only one-dimensional migration is permitted within the rock matrix. It is assumed that heat-transport is a transient process.

7. TYPICAL RUNNING TIME

Execution time is dependent on problem characteristics. The sample problems required from 0.2 to 7 CPU minutes on a DEC VAX6220. The sample problems required from 2 to 125 CP seconds on a CDC Cyber 176.

8. COMPUTER HARDWARE REQUIREMENTS

The DEC VAX version requires 1.5 Mbytes of memory. The CDC version requires 200,000 (octal) words for compilation and 172,000 (octal) words of small cone.

9. COMPUTER SOFTWARE REQUIREMENTS

SWIFT 2 ran under VMS 5.3 and NOS 2.5.1 operating systems. A Fortran compiler is required.

10. REFERENCES

M. Reeves, D. S. Ward, N. D. Johns, R. M. Cranwell, "Theory and Implementation for SWIFT II The Sandia Waste-Isolation Flow and Transport Model for Fractured Media," NUREG/CR-3328, SAND83-1159 (August 1986).

M. Reeves, D. S. Ward, N. D. Johns, R. M. Cranwell, "Data Input Guide for SWIFT II The Sandia Waste-Isolation Flow and Transport Model for Fractured Media Release 4.84," NUREG/CR-3162, SAND83-0242 (April 1986).

M. Reeves, D. S. Ward, "SWIFT II Self-Teaching Curriculum," NUREG/CR-3925, SAND84-1586 (revised January 1987).

11. CONTENTS OF CODE PACKAGE

Included in the package are the referenced documents and a DOS formatted 3.5" diskette containing a self-extracting compressed file. No executables are included with the package.

12. DATE OF ABSTRACT

January 2001.

KEYWORDS: HYDRODYNAMICS; WASTE MANAGEMENT