1. NAME AND TITLE

RIBD-II: Radioisotope Buildup and Decay Code System.

RIBD was packaged in RSIC in 1969 and replaced by later technology in 1975. An abbreviated version of the early RIBD is built into CCC-79D/ISOSHLD.

AUXILIARY ROUTINE

ZIP: BCD-to-Binary Data Processing Code.

DATA LIBRARIES

RIBD Nuclear Data: Primarily ENDF/B-IV.

MASTERIB: Nuclear Data (non-ENDF/B).

2. CONTRIBUTORS

Battelle Memorial Institute, Pacific Northwest Laboratory, Richland, Washington (original RIBD).

Hanford Engineering Development Laboratory, Westinghouse Hanford Company (RIBD-II).

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; CDC 6600 (A) and IBM 360/370 (B).

4. NATURE OF PROBLEM SOLVED

RIBD is a radioisotope buildup and decay code designed to analyze the fission product content of irradiated reactor fuel in terms of potential biological hazards and heating effects accompanying radioactive decay.

RIBD-II is used to calculate inventories, activities, decay powers, and energy releases for the fission products generated in a fuel irradiation.

5. METHOD OF SOLUTION

RIBD is a grid processor which calculates isotopic concentrations resulting from two fission sources with normal down-chain decay by beta emission and isomeric transfer and inter-chain coupling resulting from n,gamma reactions. The calculations follow the irradiation history through an unlimited number of step changes of unrestricted duration and variability including shutdown periods, restarts at different power levels and/or any other level changes.

The nuclear data library has been generated to calculate fission product inventories and decay heat rates associated with fuels irradiated in fast reactor environments.

Changes from the earlier RIBD are: expansion to include up to 850 fission product isotopes, input in the user-oriented NAMELIST format, and run-time choice of fuels from an extensively enlarged library of nuclear data. MASTERIB and other data packaged contain yield data for 818 fission product isotopes for each of fourteen different fissionable isotopes, together with fission product transmutation cross sections for fast and thermal systems. Calculational algorithms are little changed from those in RIBD.

RIBD-II has the following advantages over the earlier RIBD: improved numerics for burst-type exposures, extended library allowing greater choice of fuel types and fissioning energies, library based on ENDF/B version 4, library updating and listing features, and NAMELIST input form and improved output format.

6. RESTRICTIONS OR LIMITATIONS

None noted.

7. TYPICAL RUNNING TIME

No study has been made by RSIC of typical running times for RIBD-II.

8. COMPUTER HARDWARE REQUIREMENTS

The original RIBD was designed to run on the UNIVAC 1108; RIBD-II is operable on CDC 6600 and IBM 360/370 computers.

9. COMPUTER SOFTWARE REQUIREMENTS

A FORTRAN IV compiler is required.

10. REFERENCES

a. Included in package:

L. D. O'Dell and W. L. Bunch, "Revised Fast Reactor Library for Use with RIBD," BNWL-962 (April 1969).

J. L. Rash, "Use of Computer Code RIBD for Fission Product Analysis," RL-NRD-610 (November 1965).

D. R. Muir, "A User's Manual for Computer Code RIBD-II, A Fission Product Inventory Code" (January 1975).

R. O. Gumprecht, "Mathematical Basis of Computer Code RIBD," DUN-4136 (June 1968).

b. Background information:

D. R. Muir and W. L. Bunch, "FTR Fission Product Decay Heat," HEDL-TME 71-27 (February 1971).

11. CONTENTS OF CODE PACKAGE

Included are the referenced documents (10.a) and one (1.2MB) DOS diskette which contains the source codes, data libraries, and sample problem input. plus sample problem output.

12. DATE OF ABSTRACT

February 1972; revised July 1982 and September 1991.