CCC-0543: TORT, 2-D 3-D Discrete Ordinate Neutron and Photon Transport with Deep Penetration<br>DORT, 1-D 2-D Discrete Ordinate Neutron and Photon Transport with Deep Penetration

Program-name Package-ID Status TORT CCC-0543/01 Obsolete TORT CCC-0543/02 Obsolete TORT-DORT CCC-0543/03 Obsolete TORT-DORT CCC-0543/04 Obsolete TORT-DORT CCC-0543/05 Obsolete TORT-DORT CCC-0543/06 Tested TORT-DORT CCC-0543/07 Obsolete TORT-DORT-2.12.14 CCC-0543/08 Obsolete

Machines used: Package-ID Orig.Computer Test Computer CCC-0543/06 PC-80386 PC-80386

3. DESCRIPTION OF PROGRAM OR FUNCTION - TORT calculates the flux or fluence of particles due to particles incident upon the system from extraneous sources or generated internally as a result of interaction with the system. TORT is used in two- or three- dimensional geometric systems, and DORT is used in one- or two- dimensional geometric systems. The principle application is to the deep-penetration transport of neutrons and photons. Certain reactor eigenvalue problems can also be solved. Numerous printed edits of the results are available, and results can be transferred to output files for subsequent analysis. Note that the PC release is 2.7.3.

4. METHOD OF SOLUTION - The Boltzmann transport equation is solved using the method of discrete ordinates to treat the directional variable and finite-difference methods to treat spatial variables. Energy dependence is treated using a multigroup formulation. Time dependence is not treated. Starting in one corner of a mesh, at the highest energy, and with starting guesses for implicit sources, boundary conditions and recursion relationships are used to sweep into the mesh for each discrete direction independently. Integral quantities such as scalar flux are obtained from weighted sums over the directional results. The calculation then proceeds to lower energy groups, one at a time.
Iterations are used to resolve implicitness caused by scattering between directions within a single energy group, by scattering from an energy group to another group previously calculated, by fission, and by certain boundary conditions. Methods are available to accelerate convergence. Anisotropic scattering is represented by a Legendre expansion of arbitrary order, and methods are available to mitigate the effect of negative scattering estimates resulting from finite truncation of the expansion. Direction sets can be biased, concentrating work into directions of particular interest.
Fixed sources can be specified at either external or internal mesh boundaries, or distributed within mesh cells.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM - External forces and nonlinear physical effects cannot be treated. Penetration through large, non-scattering regions may become inaccurate due to ray effects. Problems with scattering ratios near unity or eigenvalue calculations with closely spaced eigenvalues may be quite time- consuming. Flexible dimensioning is used throughout so that fixed limits on group, problem size, etc., are applicable.

6. TYPICAL RUNNING TIME - Central processor unit (CPU) time used by the flux sweep is roughly proportional to the number of flux calculations:
space = mesh cells * directions * energy groups * iterations/group

CCC-0543/06:

NEA-DB implemented the package on an IBM/compatible 33-Mhz PC. The 21 test cases included in the package executed in 6.5 hours.

7. UNUSUAL FEATURES OF THE PROGRAM -

9. STATUS
CCC-0543/01: 25-JUN-1993 Obsolete
CCC-0543/02: 25-JUN-1993 Obsolete
CCC-0543/03: 02-JUL-1993 Obsolete
CCC-0543/04: 17-AUG-1993 Obsolete
CCC-0543/05: 20-MAY-1994 Obsolete
CCC-0543/06: 13-DEC-1993 Tested at NEADB
CCC-0543/07: 17-SEP-1998 Obsolete
CCC-0543/08: 17-SEP-1998 Obsolete

10. REFERENCES  -
- Alice F. Rice and Robert W. Roussin (Editors)
  Deterministic Methods in Radiation Transport
  A Compilation of Papers Presented February 4-5, 1992
  ORNL/RSIC-54
CCC-0543/06:
- W.A. Rhoades:
  Improved Mesh Checking
  Memo (January 11, 1993).
- W.A. Rhoades:
  TORT Version 2.5
  Memo (October 29 1992).
- W.A. Rhoades:
  TORT and DORT Abstracts
- W.A. Rhoades:
  README
  Informal Notes (1991).
- W.A. Rhoades:
  Documentation Extracted from Sources Files
  (January 1992).
- W.A. Rhoades:
  Alert Regarding Value of NTDSI
- W.A. Rhoades:
  The TORT Three-Dimensional Discrete Ordinates Neutron/Photon
  Transport Code
  ORNL-6268 (November 1987).
- W.A. Rhoades and R.L. Childs:
  An Updated Version of the DOT 4 One- and Two-Dimensional
  Neutron/Photon Transport Code
  ORNL-5851 (April 1982).
- W.A. Rhoades and M.B. Emmett:
  DOS - The Discrete Ordinates System
  ORNL/TM-8362 (September 1982).
- R.L. Childs:
  GRTUNCL - First Collision Source Program
  ORNL Informal Notes (1982).
- R.L. Childs and W.A. Rhoades:
  Theoretical Basis of the Linear Nodal and Linear Characteristic
  Methods in the TORT Computer Code
  ORNL-TM-12246 (January 1993).

11. MACHINE REQUIREMENTS - TORT runs on Cray computer, IBM RISC 6000, SUN, DEC Alpha and Hewlett-Packard workstation. The PC release runs on both 80386 and 80486 personal computers equipped with a math coprocessor and 8 Mbytes of fast memory. All sample problems were also run with only 4 Mbytes of memory with 4 Mbytes set aside for a ramdisk. Nominal hard disk requirements are around 25 Mbytes with another 25-5- Mbytes needed to run TORT sample problem number 6.

CCC-0543/06:

The package was implemented at NEA-DB on a DELL 486P/33MHz PC with 8 Mbytes of RAM.

12. PROGRAMMING LANGUAGE(S) USED -
CCC-0543/06: FORTRAN-77

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED - TORT can operate in a 100% FORTRAN configuration. On Cray, two optional assembler routines provide added speed. On IBM, two optional C routines provide time, data and location information. The Cray version runs under UNICOS version 5 or 6 using the CFT77 compiler version 4 or 5. Library calls are made to the standard UNICOS library to provide time, date, etc. On IBM, AIX version 3 was used with the XLF version 2 release 3 compiler and no library calls were made. The Sun F77 version 1.4 compiler was used under Sun Solaris 2.3. Codes were also tested on the DEC Alpha 3000 model 300 running OSF/1 (Rev. 250). Script files are included for installing on HP, in addition to the previously listed computers. The Fortran77 language standard is followed closely. An exception is the use of the traditional Hollerith data type as described in the CFT77 document. The PC executables were created using the Lahey F77L-EM/32 Fortran compiler, version 5.01, and the Phar Lap Dos Extender and virtual memory manager under DOS.

CCC-0543/06:

To implement the program and run the test cases, the PC ran under MS-DOS Version 5.0. The source code was compiled with the Lahey F77L-EM/32 Fortran-77 Version 5.11 compiler and linked with the 386LINK protected-mode linker version 5.1.

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.
developed by:
                Oak Ridge National Laboratory
                Oak Ridge, Tennessee, U. S. A.
                under:
                Defense Nuclear Agency Sponsorship

16. MATERIAL AVAILABLE -
CCC-0543/06:
CCC0543_06.001    TORTDORT.INF Information file                    1172 records
CCC0543_06.002    TORTDORT.EXE Self-extracting ZIP file               0 records
CCC0543_06.003    DOS file-names                                      2 records

17. CATEGORIES  -

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

Keywords: DISCRETE ORDINATE METHOD, NEUTRON TRANSPORT THEORY, ONE-DIMENSIONAL, PHOTON TRANSPORT, SHIELDING, THREE-DIMENSIONAL, TWO-DIMENSIONAL