1. NAME AND TITLE

COLUMN2: Calculation of Effects of Physicochemical Processes on Migration.

2. CONTRIBUTOR

Riso National Laboratory, Roskilde, Denmark, through the NEA Data Bank, Gif-sur-Yvette, France.

3. CODING LANGUAGE AND COMPUTER

Fortran 77; IBM 3090 and VAX 11/780 (C00534ALLMF00)

4. NATURE OF PROBLEM SOLVED

COLUMN2 is designed for studies of the effects of various physicochemical processes on radionuclide migration in one dimension. It solves the solute transport equation and can take into account dispersion, sorption, ion exchange, first and second order homogeneous chemical reactions. Spacial variations of input pulses and retention factors are possible.

5. METHOD OF SOLUTION

The solution is based on a finite difference method followed by the application of the method of characteristics on two separate grid systems.

6. RESTRICTIONS OR LIMITATIONS

For computational reasons the number of components has been limited to 5 and the maximum number of second order reactions is 10. However, a redimensioning of all relevant arrays will allow for any number of components and reactions. The maximum number of grid points, default value 801, may be enlarged to redimension all relevant arrays.

7. TYPICAL RUNNING TIME

Test cases 3A through 3E have a typical CPU-time of 1 minute. NEA-DB ran the test cases included in this package on the IBM 3090 and the VAX 11/780 computers. Execution times varied between 11 seconds and 6 minutes on the VAX; the variation was between 1 second and 2.5 minutes on the IBM.

8. COMPUTER HARDWARE REQUIREMENTS

An IBM 3090 or a VAX 11/780 computer is required. Main storage requirements for running the test cases are: 400 K bytes (IBM 3090).

9. COMPUTER SOFTWARE REQUIREMENTS

A Fortran 77 compiler is required. The operating system for testing on the IBM 3090 was MVS-XA and on the VAX was VMS 4.6. The Risoe Interactive Graphics System (RIGS) was used for plotting.

10. REFERENCES

O. J. Nielsen, P. Bo, and L. Carlsen, "COLUMN2--A Computer Program for Simulating Migration," RISO-R-514 (October 1985).

S. Rahbek, S. Frederiksen, and E. Hansen, "RISO Interactive Graphics System," RISO-M-2605 (October 1986).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one (1.2MB) DOS diskette which contains the source codes, an information file, interface routines (VAX only), JCL, and sample problem input and output.

12. DATE OF ABSTRACT

December 1988.