1. NAME AND TITLE

GABAS: A Code System for Generating Composite Time-Dependent Fission Produce Spectra.

AUXILIARY ROUTINES

ISPEC: Reads fission product spectral data and writes a binary file for input to GABAS.

2. CONTRIBUTORS

Instrumentation Research Technology, San Diego, California.

Sandia National Laboratories, Albuquerque, New Mexico.

3. CODING LANGUAGE AND COMPUTER

Fortran IV; UNIVAC 1100/81.

4. NATURE OF PROBLEM SOLVED

GABAS calculates time-dependent beta- and/or gamma-ray spectra from decaying fission products.

5. METHOD OF SOLUTION

GABAS calculates composite fission-product beta and/or gamma-ray spectra based on the technique used by England, et al., in conjunction with the CINDER family of fission product codes. Multigroup beta and gamma-ray spectra for individual nuclides are folded with their corresponding time-dependent activities (usually generated by a fission product inventory code) to produce a composite time-dependent fission product spectrum. GABAS was intended to interface with the fission product inventory code RIBD-IRT; however, other codes like ORIGEN or CINDER could be utilized with appropriate modifications to their output format.

6. RESTRICTIONS OR LIMITATIONS

None noted.

7. TYPICAL RUNNING TIME

For 34 time steps and 180 fission products, the approximate CPU time was 10 seconds.

8. COMPUTER HARDWARE REQUIREMENTS

GABAS is operable on the UNIVAC 1100/81 computer. Two mass storage files, either tapes or discs, and a printer are needed.

9. COMPUTER SOFTWARE REQUIREMENTS

A Fortran IV compiler is required.

10. REFERENCES

a. Included in documentation:

D. D. Thayer and N. A. Lurie, "A User's Manual for the GABAS Spectrum Computer Code," IRT 6406-004, January 1982.

b. Background information:

M. G. Stamatelatos and T. R. England, "FPDCYS and FPSPEC: Computer Programs for Calculating Fission-Product Beta and Gamma Multigroup Spectra from ENDF/B-IV Data," LA-NUREG-6818-MS (May 1977).

D. D. Thayer and N. A. Lurie, "A User's Manual for Computer Code RIBD/IRT," IRT 6406-003, SAND 82-7013, NUREG/CR-2393 (January 1982).

T. R. England and M. G. Stamatelatos, "Multigroup Beta and Gamma Spectra of Individual ENDF/B-IV Fission Product Nuclides," LA-NUREG-6622-MS (December 1976).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document (10.a) and one (1.2MB) DOS diskette which contains the source program and sample problem input.

12. DATE OF ABSTRACT

February 1982; August 1984.