1. NAME AND TITLE

DIFMOD: A Computer Program To Calculate The Leaching Of Radionuclides And The Corrosion Of Cemented Waste Forms in Water or Brine.

2. CONTRIBUTOR

Institüt fÜr Nukleare Entsorgungstechnik, KFK, Karlsruhe, Germany, through the NEA Data Bank Gif-sur-Yvette, Cedex, France.

3. CODING LANGUAGE AND COMPUTER

Fortran 77; IBM 3083.

4. NATURE OF PROBLEM SOLVED

DIFMOD calculates the leaching of radionuclides and the corrosion of cemented waste forms in contact with water or brine.

5. METHOD OF SOLUTION

DIFMOD computes both the behavior of specimens in the laboratory-scale experiments and provides a forecast of the behavior of waste forms in the case of an accidental drowning of a repository. The mathematical formalism describes leaching and corrosion on the basis of diffusion and dissolution processes and of the chemical reactions by corrosion.

6. RESTRICTIONS OR LIMITATIONS

A total of 1000 spatial increments is allowed.

7. TYPICAL RUNNING TIME

On the IBM 3083 at NEA Data Bank, the CPU time required for the different cases varied between 2.5 to 222 seconds.

8. COMPUTER HARDWARE REQUIREMENTS

DIFMOD runs on the IBM 3083.

9. COMPUTER SOFTWARE REQUIREMENTS

The code was written in Fortran 77. On the IBM 3083, the compiler used was VS Fortran under the MVS/XA operating system.

10. REFERENCE

a. Included in the documentation:

B. Kienzler. Mathematical Modelling Of The Corrosion and Leaching Behavior Of Cemented Waste Forms, KFK-3905, (May 1985), Karlsruhe, Germany (in German).

b. Background information:

B. Kienzler and R. H. Koester, ``Experimental and Theoretical Investigations Of Corrosion Mechanisms In Cemented Waste Forms,'' Nuclear Technology, Vol. 71, No. 12 (1985), 590--596.

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one DS/HD (1.2 MB) 5.25 inch diskette.

12. DATE OF ABSTRACT

December 1990.