NESC0325 2DB

1. NAME OR DESIGNATION OF PROGRAM:  2DB

3. DESCRIPTION OF PROBLEM OR FUNCTION

2DB is   a   flexible,   two-
dimensional (x-y, r-z,  r-theta, hex geometry) diffusion  code for
use in fast reactor analyses.  The code can be used to:
   (a)  Compute fuel burnup using a flexible material shuffling
        scheme.
   (b)  Perform criticality searches on time absorption (alpha),
        material concentrations, and region dimensions using a
        regular or adjoint model.  Criticality searches can be
        performed during burnup to compensate for fuel depletion.
   (c)  Compute flux distributions for an arbitrary extraneous
        source.

4. METHOD OF SOLUTION

Standard   source-iteration  techniques   are
used.  Group  rebalancing and successive overrelaxation  with line
inversion are used to accelerate  convergence.  Material burnup is
by reactor  zone.  The burnup rate  is determined by the  zone and
energy (group) averaged cross sections  which are recomputed after
each time-step.  The isotopic chains, which can contain any number
of isotopes,  are formed by the  user.  The code does  not contain
built-in or internal chains.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

Since     variable
dimensioning is  employed, no  simple bounds  can be  stated.  The
current  1108 version,  however,  is  nominally restricted  to  50
energy groups  in a  65K memory.   In the  6600 version  the power
fraction, average burnup rate, and breeding ratio calculations are
limited to reactors with a maximum of 50 zones.

6. TYPICAL RUNNING TIME

A keff calculation with a  30x30 mesh and 4
energy groups requires approximately one minute.  A typical burnup
calculation  requires roughly  twice the  machine time  of a  keff
calculation.

7. UNUSUAL FEATURES OF THE PROGRAM

The input  data are  arranged so
the  code can  be easily  used  for keff  and search  calculations
without burdening the user with burnup parameters.

8. RELATED AND AUXILIARY PROGRAMS

The  input   data  (e.g.,   cross
sections, flux  dumps, geometry,  and composition  specifications)
are  compatible  with  the Los  Alamos  one-  and  two-dimensional
transport  codes,  DTF4  (NESC  Abstract 209)  and  2DF,  and  the
Battelle perturbation code,  PERT4 (NESC Abstract 304).   All four
codes  use the  same input  module.  The  logical flow  of 2DB  is
patterned after the 2DF code.

10. REFERENCES

- W.W. Little, Jr. and R.W. Hardie,
  2DB, A Two-dimensional Diffusion-Burnup Code for Fast Reactor
  Analysis,
  BNWL-640, January 1968, Addendum and Errata, April 12, 1968.
- T.J. Hirons and R.D. O'Dell,
  CDC-6600 Version of 2DB, A Two-dimensional Diffusion-burnup Code
  for Fast Reactor Analyses,
  LASL Note K-1-l-776, February 5, 1969.
- 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.

- W.W. Little, Jr. and R.W. Hardie:
  2DB Users Manual, Revision 1
  BNWL-831, Rev. 1, (February 1969).

11. MACHINE REQUIREMENTS:  65K  memory  and three  peripheral  storage
devices.

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:

15. NAME AND ESTABLISHMENT OF AUTHORS

   1108          W. W. Little, Jr. and R. W. Hardie
                 Pacific Northwest Laboratories
                 Battelle
                 P. O. Box 999
                 Richland, Washington  99352
   6600          T. J. Hirons and R. D. O'Dell
                 Los Alamos Scientific Laboratory
                 P. O. Box 1663
                 Los Alamos, New Mexico  87544

File name	File description	Records
NESC0325_02.001	SOURCE 360/65	2804
NESC0325_02.002	SUBROUTINES ETIME,NTRAN & DATA INPUT	130
NESC0325_02.003	OUTPUT	1663