CCC-0320: DOT-4.2, 2-D Neutron Transport, Gamma Transport with Space Dependent Mesh and Quadrature

Program-name Package-ID Status DOT-4.2 CCC-0320/01 Obsolete DOT-4.2 CCC-0320/02 Obsolete DOT-4.2 CCC-0320/03 Obsolete DOT-4.2 CCC-0320/04 Tested DOT-4/VE CCC-0320/05 Obsolete DOT-4.2 CCC-0320/06 Obsolete

Machines used: Package-ID Orig.Computer Test Computer CCC-0320/04 IBM 3033 IBM 3081

3. DESCRIPTION OF PROGRAM OR FUNCTION - DOT-4 determines the flux or fluence of particles throughout a two-dimensional geometric system due to sources either generated as a result of particle interaction with the medium, or incident upon the system from independent sources. The principal application is to the deep penetration transport of neutrons and photons. Criticality (k-type and search) problems can be solved. Numerous printed edits of the results are available, and results can be transferred to output files for subsequent analysis.

4. METHOD OF SOLUTION - The Boltzmann transport equation is solved using the method of discrete ordinates, diffusion theory, or a special "combined P1" solution. In the discrete ordinates method, the primary mode of operation, balance equations are solved for the flow of particles moving in a set of discrete directions in each cell of a space mesh, and in each group of a multigroup energy mesh. Iterations are performed until all implicitness in the coupling of cells, directions, groups, and source regeneration has been resolved. Methods are available to accelerate convergence by space- dependent rebalance and by successive over-relaxation. Anisotropic cross sections can be expressed in a Legendre expansion of arbitrary order. Output data sets can be used to provide an accurate restart of a previous problem.
Special techniques are available to remove the effects of negative fluxes caused by the finite space and direction meshes, and of negative scattering due to truncation of the cross-section expansion. The space mesh can be described such that the number of first-dimension (I) intervals varies with the second dimension (J). The number of discrete directions can vary across the space mesh and with energy. The order of Legendre expansion can vary with cross- section set and with energy group.
Provision is made to treat sources resulting from the first collision of particles from a point source. In this case, flux due to uncollided particles is included in the output edits.
Direction sets can be biased, with more discrete direction segments per unit solid angle in some directions than in others.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM - External force fields or non linear effects cannot be treated. Flexible dimensioning is used throughout, so that no restrictions are imposed on individual problem parameters. Certain options, especially diffusion and P1 theories, are not compatible with variable mesh and quadrature problems.
DOT-4/VE: The vectorized algorithm is not used with variable mesh and quadrature problems.

6. TYPICAL RUNNING TIME - Running time is roughly proportional to:
Flux work units (FWU) = number of space mesh cells x number of
directions x number of energy groups x
number of iterations per group.
Depending on the options chosen, a rate of 1.3 to 2.3 million FWU per minute on the IBM 360/195 is typical. Thus, a very large problem with 5000 space cells, 48 directions, 50 energy groups, and 10 iterations per group would require roughly 1 to 1.5 hours fo 360/195 CPU time.

7. UNUSUAL FEATURES OF THE PROGRAM -
In DOT-4/VE, the algorithm used in the calculation is partially vectorized. Problems with large number of spatial meshes and of discrete ordinates and with highly anisotropic scattering take maximum benefit from this feature.

9. STATUS
CCC-0320/01: 23-JUL-1984 Obsolete
CCC-0320/02: 24-OCT-1996 Obsolete
CCC-0320/03: 24-OCT-1996 Obsolete
CCC-0320/04: 20-JUL-1984 Tested at NEADB
CCC-0320/05: 09-MAR-2000 Obsolete
CCC-0320/06: 25-NOV-1998 Obsolete

10. REFERENCES  -
- W.A. Rhoades and F.R. Mynatt:
  The DOT-III Two-Dimensional Discrete Ordinates Transport Code
  ORNL-TM-4280 (September 1973)
- F.R. Mynatt, F.J. Muckenthaler and P.N. Stevens:
  Development of a Two-Dimensional Discrete Ordinates Transport
  Theory for Radiation Shielding
  CTC-INF-952 (August 1969)
- R. Douglas O'Dell and Raymond E. Alcouffe:
  Transport Calculations for Nuclear Analyses: Theory and
  Guidelines for Effective Use of Transport Codes
  LA-10983-MS and UC-32 (September 1987)
- B. Barbucci, G. Mariotti:
  Development of a Vectorized Version of the DOT Code for an
  IBM 2090/200 VF Computer.
  Proc. of 7th Int. Conf on Radiation Shielding,
  Bournemouth (UK), 1988
CCC-0320/04:
- W.A. Rhoades:
  Informal Notes  (October 1979)
- W.A. Rhoades, D.B. Simpson, R.L. Childs and W.W. Engle Jr.:
  The DOT-4 Two Dimensional, Discrete-Ordinates Transport Code with
  Space-Dependent Mesh and Quadrature.
  ORNL/TM-6529  (August 1978)
- DOT-4 Problem Set Descriptions
  (April 1978)
- W.A. Rhoades:
  RTFLUM - A Module for Converting, Expanding, and Editing
  Standard Flux Files.
  (April 1978)
- W.A. Rhoades:
  The GIP Program for Preparation of Group-Organized
  Cross Sections Libraries
  (April 1978)
- ITOM - A Module to Convert ISOTXS Files to MATXS Format
  (April 1978)
- W.A. Rhoades:
  The FBSAM Data Transmission Package for IBM 360/370 Computers.
  ORNL/TM-5199  (January 1976)
- D.B. Simpson and W.A. Rhoades:
  The CFLAG Code
  (April 1978)
- W.A. Rhoades:
  The DOT-IV Variable Mesh Discrete Ordinates Transport Code.
  Preprint of Paper 5 of Session P2 to be Included in Proceedings
  of 5th International Conference on Reactor Shielding, Knoxville
  (April 18-22, 1977)
- W.A. Rhoades:
  Discrete Ordinates System Note 5 on "Space-Dependent
  Rebalance Parameters  (September 1978)
- W.A. Rhoades, R.L. Childs and W.W. Engle, Jr.:
  Comparison of Rebalance Stabilization Methods for Two-Dimensional
  Transport Calculations.

11. MACHINE REQUIREMENTS - Memory must be approximately 50,000 words for a small problem, expanding wht problem size. External data storage must be provided for 8 scratch files, of which 4 must be direct (random) access. User-supplied input and output data files must be supplied on sequential-access devices, e.g. tapes or equivalent.
CCC-320/02: Main storage requirements to execute the test case on CDC CYBER 170/740 are 220,600 (octal) words.

12. PROGRAMMING LANGUAGE(S) USED -
CCC-0320/04: FORTRAN+ASSEMBLER

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED - The IBM version uses OS version 21. No special requirements are made of the operating system. Two types of overlay facility can be used if available.
CCC-320/02: The test case has been executed by NEA-DB on CDC CYBER 170/740 under the NOS 4.1 operating system.

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS -

15. NAME AND ESTABLISHMENT OF AUTHORS -
     Contributed by:
                     Radiation Shielding Information Center
                     Oak Ridge National Laboratory
                     Oak Ridge, Tennessee, U. S. A.
     DOT-4/VE:       P. Barbucci and G. Mariotti
                     ENEL
                     Thermal and Nuclear Research Center
                     PISA, Italy

16. MATERIAL AVAILABLE -
CCC-0320/04:
CCC0320_04.003    DOT-4.2 INFORMATION FILE                           46 records
CCC0320_04.004    DOT-4.2 SOURCE (FORTRAN-4)                      11897 records
CCC0320_04.005    DOT-4.2 SOURCE (ASSEMBLER)                       4094 records
CCC0320_04.006    GIP SOURCE (FORTRAN-4)                           2464 records
CCC0320_04.007    RTFLUM SOURCE (FORTRAN-4)                        2369 records
CCC0320_04.008    ROUTINES NEEDED BY GIP, RTFLUM (ASSEMBLER)        372 records
CCC0320_04.009    JCL FOR JOB COMPILE,LINK,RUN                     1737 records
CCC0320_04.010    DOT-4.2 PRINTED OUTPUT OF TEST CASES            13720 records

17. CATEGORIES  -

- C.  Static Design Studies
- J.  Gamma Heating and Shield Design

Keywords: ANISOTROPIC SCATTERING, DISCRETE ORDINATE METHOD, LEGENDRE POLYNOMIALS, NEUTRON TRANSPORT THEORY, SHIELDING, TWO-DIMENSIONAL