1. NAME AND TITLE

GETOUT: A Computer Code System for Predicting One-Dimensional Radionuclide Decay Chain Transport through Geologic Media.

2. CONTRIBUTOR

Office of Nuclear Waste Isolation (ONWI), Battelle Project Management Division, Columbus, Ohio.

3. CODING LANGUAGE AND COMPUTER

Fortran IV; CDC CYBER 176.

4. NATURE OF PROBLEM SOLVED

GETOUT analyzes the convective-dispersive transport of radionuclides in groundwater. The output from the code consists of nuclide discharges at the biosphere.

GETOUT can be used as a site subsystem process code for estimating the nuclide discharges into biosphere points, following a leach incident at the repository. It is able to interface with NETFLO, a flow code, and PABLM, a dose-to-man code. The sequential operation of NETFLO, GETOUT, and PABLM may be used for the total site subsystem assessment.

5. METHOD OF SOLUTION

GETOUT evaluates the analytical solution presented by Lester, Cloninger, and Burkholder, employing the Laplace transform technique. The basic assumptions in the code are: 1) the flow is one-dimensional so lateral dispersion is neglected; 2) the solution is limited to straight chains; 3) the porous medium is homogeneous with respect to porosity, bulk density, dispersion coefficient, and retardation factors for each nuclide; 4) the fluid flow is steady-state and the velocity of water is constant throughout the column; 5) theoretically, the flow path is infinite; 6) the entire inventory is dissolved in water without regard to solubility limits.

6. RESTRICTIONS OR LIMITATIONS

(1) For single chain option, the present dimension limits restrict the output to 202 discrete points in the time coordinate; (2) neglects lateral dispersion; (3) limited to three nuclides per nuclide decay chain; (4) does not handle branched chains of nuclide decay; (5) some combinations of Peclet and decay numbers and retardation factors cannot be handled for two-member and three-member chains; (6) retardation factors for the different nuclides in a chain must be unequal; (7) flow is taken to be in steady-state; (8) interstitial velocity is taken to be the same throughout the path of travel of nuclides; and (9) retardation factor for a nuclide is taken to be constant over the path of travel of nuclides.

7. TYPICAL RUNNING TIME

No specific running time is given, but the author states that the strength of the code lies in the small computer time required in comparison to other numerical nuclide transport codes.

8. COMPUTER HARDWARE REQUIREMENTS

41 K decimal words of memory to load and run on the CDC CYBER 176.

9. COMPUTER SOFTWARE REQUIREMENTS

A Fortran IV compiler is required.

10. REFERENCE

"GETOUT: A Computer Code for One-Dimensional Analytical Solution for Radionuclide Transport," ONWI-433 (April 1983).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one (1.2MB) DOS diskette which contains the source codes, library, and sample problem input and output.

12. DATE OF ABSTRACT

September 1984.