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
  Equation 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