Software

REBUS-3 (Fuel Cycle / Depletion Codes)

Standard Code Description

1. Name of Program:
   REBUS-3
2. Computer for Which Program is Designed and Other Machine Version Packages Available:
   Unix Workstations (SUN SparcStation, IBM RS6000), CRAY X-MP & IBM 30xx
3. Description of Problem Solved:
   REBUS-3 is a system of codes designed for the analysis of reactor fuel cycles. Two basic types of problems are solved: 1) the infinite-time, or equilibrium, conditions of a reactor operating under a fixed fuel management scheme, or, 2) the explicit cycle-by-cycle, or nonequilibrium operation of a reactor under a specified periodic or non-periodic fuel management program. For the equilibrium type problems, the code uses specified external fuel supplies to load the reactor. Optionally, reprocessing may be included in the specification of the external fuel cycle and discharged fuel may be recycled back into the reactor. For non-equilibrium cases, the initial composition of the reactor core may be explicitly specified or the core may be loaded from external feeds and discharged fuel may be recycled back into the reactor as in equilibrium problems.
   Four types of search procedures may be carried out in order to satisfy user-supplied constraints: 1) adjustment of the reactor burn cycle time to achieve a specified discharge burnup, 2) adjustment of the fresh fuel enrichment to achieve a specified multiplication constant at a specified point during the burn cycle, 3) adjustment of the control poison density to maintain a specified value of the multiplication constant throughout the reactor burn cycle, and 4) adjustment of the reactor burn cycle time to achieve a specified value of the multiplication constant at the end of the burn step.
4. Method of Solution:
   The total reactor burn cycle time is divided into one or more subintervals, the number of which is specified by the user. An explicit nuclide depletion computation is performed in each region of the reactor over each of these subintervals using the average reaction rates over the subinterval. These average reaction rates are based on fluxes obtained from an explicit 1-, 2-, or 3-dimensional diffusion theory neutronics solution computed at both the beginning and end of the subinterval. The nuclide transmutation equations are solved by the matrix-exponential technique. The isotopes to be considered in the burnup equations, as well as their transmutation reactions, are specified by the user.
5. Restrictions on the Complexity of the Problems:
   Flux calculations are performed for homogenized nodes or mesh cells using one of the solution options available in the DIF3D neutronics module. Microscopic cross sections within each depletion zone can depend on the density of at most one active nuclide within that zone. No thermal-hydraulic feedback effects are represented.
6. Typical Running Time:
   3-30 minutes or longer depending on size and complexity of problem and machine utilized.
7. Unusual Features of the Program:
   Will handle both equilibrium and non-equilibrium problems using a number of different core geometries including triangular and hexagonal mesh. The neutronics solution may be obtained using finite difference or nodal diffusion-theory methods for a variety of multidimensional Cartesian, hexagonal or curvilinear geometry options. Fuel management is completely general for nonequilibrium problems. Microscopic cross sections are permitted to vary as a function of the atom density of designated reference isotopes in the problem. The user may specify control rod positions at each time node in the problem. A number of relational database datasets containing various types of summary results are available for use in tailoring reports. Additional features include (a) fully automatic restart capability; (b) no restrictions on number of neutron energy groups; and (c} general external cycle with no restrictions on number of external feeds, reprocessing plants, etc.
8. Related and Auxiliary Programs:
   REBUS-3 (Refs. 1, 2) is fully compatible with the CCCC (Ref. 3) coding standards and interface data sets. It utilizes the DIF3D code (Ref. 4, 5) to obtain the neutronics solution. DIF3D (with finite difference and hexagonal nodal option) is included in the code package.
9. Status:
   The modular version of the code is in production use at Argonne National Laboratory. A standalone version has been exported to the Radiation Safety Information Computational Center (RSICC) at Oak Ridge National Laboratory.
10. References:
    1. B. J. Toppel, "The Fuel Cycle Analysis Capability REBUS-3," Argonne-83-2 Argonne National Laboratory (March 1983).
    2. R. P. Hosteny, "The ARC System Fuel Cycle Analysis Capability, REBUS-2," Argonne-7721 Argonne National Laboratory (October 1978).
    3. R. Douglas O'Dell, "Standard Interface Files and Procedures for Reactor Physics Codes, Version IV," UC-32 Los Alamos Scientific Laboratory (September 1977).
    4. K. L. Derstine, "DIF3D: A Code to Solve One-, Two-, and Three-Dimensional Finite-Difference Diffusion Theory Problems," Argonne-82-64, Argonne National Laboratory (April 1984).
    5. R. D. Lawrence, "The DIF3D Nodal Neutronics Option for Two- and Three-Dimensional Diffusion Theory Calculations in Hexagonal Geometry," Argonne-83-1 Argonne National Laboratory (March 1983).
11. Machine Requirements:
    At least 16 M bytes of RAM are recommended for program and file buffer storage on a Unix workstation. External data storage must be available for approximately 40 scratch and interface files. Fourteen of these files are random access scratch files (grouped into 6 file groups) and the remainder are sequential access files with formatted or unformatted record types.
12. Programming Languages Used:
    FORTRAN '77 is used. The program can be executed entirely in FORTRAN. Optional dynamic memory allocation and timing routines supplied from host machine libraries or code in "C" may be used on Unix workstations and the CRAY XMP.
13. Operating System:
    No special requirements are made on the operating system. SunOS 4.1.3x and SOLARIS 2.5 (for SPARCstations), AIX 3.2 on the IBM RS6000, the XMP UNICOS operating system segmentation loader (segldr) and the IBM (MVS/JES3) linkage editor overlay facilities may be used.
14. Other Programming or Operating Information or Restrictions:
    The standalone source code contains approximately 178000 FORTRAN statements.
15. Name and Establishment of Author or Contributor:
    • B. J. Toppel
      Nuclear Engineering Division
      Argonne National Laboratory
      9700 South Cass Avenue
      Argonne, Illinois 60439
16. Materials Available: Restricted distribution.
    
    • Implementation Instructions
    • Electronic Media UNIX "Tar" File including,
        - Source Code
        - 16 Sample Input and Output Listings
        - REBUS-3 Documentation (updated version of Argonne-83-2 [Ref. 1] )
17. Sponsor:
    U.S. Department of Energy, Office of Nuclear Energy, Science, and Technology.

Last Modified: Tue, September 20, 2011 11:13 AM