CCC-0532 DORT-PC.

1. NAME OR DESIGNATION OF PROGRAM:  Two-Dimensional Discrete Ordinates
Transport Code System.

3. DESCRIPTION OF PROGRAM OR FUNCTION

This version of DORT (ORNL Mod  5, 12 Oct 89, INEL Ver 2.1) was derived from the Cray UNICOS version distributed in CCC-543/TORT, which was developed at ORNL under Defense Nuclear Agency sponsorship. DORT is directly based on the earlier DOT codes. DORT-PC determines the fluence of particles throughout one- or two-dimensional geometric systems due to sources  either generated as a result of particle interaction with the medium or incident upon the system from extraneous sources. The principal application is to the deep-penetration transport of neutrons and photons. Criticality (k-type and search) problems can also 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 either the method of discrete ordinates or diffusion theory approximation. 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 structure. Iterations are performed until all implicitness in the coupling of cells, directions, groups, and source regeneration has been resolved. Several methods are available to accelerate convergence. 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 or to deliver information to other codes. Several techniques are available to remove the effects of negative fluxes caused by the finite difference approximation and of negative scattering sources due to truncation of the cross-section expansion. The space mesh can be described such that the number of first-dimensional (i) intervals varies with the second dimension (j). The number of discrete directions can vary across the space mesh and with energy. Direction sets can be biased, with discrete directions concentrated such as to give fine detail to streaming phenomena.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

External force fields or nonlinear effects cannot be treated. Flexible dimensioning is used throughout so that no restrictions are imposed on individual problem parameters. Certain options, especially diffusion theory, are not compatible with variable mesh and quadrature problems.

6. TYPICAL RUNNING TIME

Running time varies from a few minutes to many hours depending on the complexity of the problem and whether or not extended memory is available. The extended memory version typically runs about three times faster than the 640K version for a  given application.

7. UNUSUAL FEATURES OF THE PROGRAM:

8. RELATED AND AUXILIARY PROGRAMS

GIP: Prepares required macroscopic  cross sections for DORT-PC.

10. REFERENCES:

- Dave Nigg:
  READ.ME
  Informal Notes (August 1991).
- 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, pp. 33-46 (September 1982).

11. MACHINE REQUIREMENTS

DORT-PC runs on IBM PC or PS/2 computers with at least 640K RAM, a math co-processor and 40 Mb of fixed disk. With minor changes, the same source has been compiled and run on IBM RISC workstations.

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED

The extended memory version was manufactured using the Lahey F77L-EM32 Fortran compiler Version 4.01, the Eclipse Linker Version 2.1.05 and the Eclipse Binder Version 1.3.0. (Linker and Binder are also distributed by Lahey.) The 640K version was manufactured using the Lahey F77L Fortran compiler Version 2.22 and the Phoenix PLINK86 Overlay Linker Version 1.48 (DORT-PC) and the Microsoft DOS Linker Version 2.30 (GIP).

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:

15. NAME AND ESTABLISHMENT OF AUTHORS

Idaho National Engineering
Laboratory, Idaho Falls, Idaho.

File name	File description	Records
CCC0532_01.001	Information file	34
CCC0532_01.002	PC installation instructions	23
CCC0532_01.003	Author's information	144
CCC0532_01.004	Source,data,output (compressed)	0
CCC0532_01.005	Executables (compressed)	0
CCC0532_01.006	DOS file-names	5