NESC0374 1-DX.

1. NAME OR DESIGNATION OF PROGRAM:  1DX

3. DESCRIPTION OF PROBLEM OR FUNCTION

1DX is a multipurpose, one-dimensional diffusion code for generating cross sections to be used in fast reactor analyses. The code is designed to
(a) compute and punch resonance shielded cross sections using data in the Russian (see reference 2) format,
(b) compute and punch group-collapsed microscopic and/or macroscopic cross sections averaged over the spectrum in any specified zone, and
(c) compute keff and perform criticality searches on time absorption, material concentrations, zone dimensions, and buckling using either a flux or an adjoint model.

4. METHOD OF SOLUTION

Resonance shielded cross sections are calculated using data (infinite dilution cross sections and resonance shielding factors) in the Russian format. Interpolation schemes are used to compute shielding factors applicable to specific compositions. A flux iteration option for computing the elastic removal cross section is also included. Group-collapsed cross sections by reactor zone are calculated using flux weighting. The eigenvalue and spatial flux profiles are computed using standard source-iteration techniques. Convergence is accelerated using fission source overrelaxation. 1DX will also accept input cross sections in the DTF format (i.e., resonance shielded cross sections).

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

1DX uses variable dimensioning to make maximum use of existing core storage. All subscripted variables are stored in one array dimensioned to 35,000 on the UNIVAC1108. Allocation is dynamic in the IBM version.

6. TYPICAL RUNNING TIME

A representative 26-group problem with 30 spatial intervals using data in the Russian format requires about 50 seconds on a UNIVAC1108. If the cross section data is already in the DTF format, the same problem would require about 5 seconds. The sample problem requires 12 seconds of CPU time on an IBM370/195.

7. UNUSUAL FEATURES OF THE PROGRAM:

8. RELATED AND AUXILIARY PROGRAMS

The format of the input data (e.g., flux dumps, geometry and composition specifications, etc.) is compatible with Los Alamos one- and two-dimensional transport codes DTF4 (NESC Abstract 209) and 2DF (NESC Abstract 173), the BNW two-dimensional burnup code 2DB (NESC Abstract 325), and the BNW perturbation code PERT4 (NESC Abstract 304). The computer code ETOX will prepare cross section data in the Russian format from the ENDF/B data tape. PUPX is an auxiliary program that prints, updates, and punches cross section data in the Russian format using a binary tape.

10. REFERENCES

- I.I. Bondarenko, et al.,
Group Constants for Nuclear Reactor Calculations, Consultants Bureau, New York, 1964.
- K.D. Lathrop,
DTF-IV, A FORTRAN-IV Program for Solving the Multigroup Transport
Equatio with Anisotropic Scattering LA-3373, July 15, 1965.
- 2DF, A Two-dimensional Transport Code from the Los Alamos Scientific Laboratory (unpublished).
- R.W. Hardie and W.W. Little, Jr.,
PERT-IV, A Two-dimensional Perturbation Code in FORTRAN-IV BNWL-409, April 1967.
- R.E. Schenter, J.L. Baker, and R.B. Kidman,
ETOX, A Code to Calculate Group Constants for Nuclear Reactor Calculations BNWL-1002, May 1969.

- R.W. Hardie and W.W. Little, Jr.:
  1-DX, A One-dimensional Diffusion Code for Generating Effective
  Nuclear Cross Sections
  BNWL-954 (March 1969).
- W.W. Little, Jr. and R.W. Hardie:
  2DB User's Manual, Revision 1
  BNWL-831, Rev.1 (February 1969).
- R.W. Hardie and W.W. Little, Jr.:
  1-DX, A One-dimensional Diffusion Code for Generating Effective
  Nuclear Cross Sections
  BNWL-954 (March 1969).
- W.W. Little, Jr. and R.W. Hardie:
  2DB User's Manual, Revision 1
  BNWL-831, Rev.1 (February 1969).

11. MACHINE REQUIREMENTS

65K memory and 7 peripheral storage devices (UNIVAC1108), 145K and maximum of 8 storage devices (IBM360,370).

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:  OS/360,370 (IBM360,370).

15. NAME AND ESTABLISHMENT OF AUTHORS

   1108          R. W. Hardie
                 Pacific Northwest Laboratories
                 Battelle
                 P. O. Box 999
                 Richland, Washington  99352
   360,370       H. Henryson, II
                 Applied Physics Division
                 Argonne National Laboratory
                 9700 South Cass Avenue
                 Argonne, Illinois  60439

File name	File description	Records
NESC0374_03.001	1-DX SOURCE PROGRAMME	3018
NESC0374_03.002	DD,OVERLAY CARDS+SAMPLE INPUT	452
NESC0374_03.003	AUXILIARY ROUTINE PUPX SOURCE	216
NESC0374_03.004	SAMPLE OUTPUT OF 1-DX	1177

File name	File description	Records
NESC0374_04.001	SOURCE PROGRAM (FORTRAN) + SAMPLE INPUT	1208
NESC0374_04.002	SAMPLE OUTPUT	1110