NESC0156 EXTERMINATOR2

1. NAME OR DESIGNATION OF PROGRAM:  EXTERMINATOR2

3. DESCRIPTION OF PROBLEM OR FUNCTION

The multigroup,          two-
dimensional neutron diffusion equations are solved in x-y, r-z, or
r-theta geometry.

4. METHOD OF SOLUTION

The   EQUIPOISE  method   (reference  2)   is
employed to solve the finite-difference  analogs of the multigroup
neutron diffusion equations.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

Since  FORTRAN  IV
variable-dimensioning techniques  were used in  EXTERMINATOR2, the
only restriction  on problem size  is the available  core storage.
The code examines the problem size  and stores fluxes and equation
coefficients (except for scattering  matrix coefficients which are
recalculated at each iteration) according to the machine core size
in one of four ways -
   (1)  All fluxes and equation coefficients are contained in
        core and no I/O devices are used during the iterative
        part of the calculation.
   (2)  All equation coefficients are contained in core and I/O
        devices are used to store the fluxes.
   (3)  The fluxes are contained in core and I/O devices are used
        to store the equation coefficients.
   (4)  Both coefficients and fluxes are used from I/O devices.
   For a  problem with an I*J  mesh, K energy groups,  M different
materials, N nuclides, and L sets of specifications of composition
locations,  the core  storage  required  for variables,  when  all
fluxes and coefficients are used from I/O devices, is
        4*I + 24*J + 16*K + 2*M + 6*N + (2*M + N + 1)*K**2
        + 8*I*J + 14*J*K + 15*M*K + M*N + 4*N*K + 5*L + 8
words.  The core storage required to be able to contain the fluxes
and coefficients in core is
        4*I + 24*J + 16*K + 2*M + 6*N + (2*M + N + 1)*K**2 +
        8*I*J + 4*J*K + 15*M*K + M*N + 4*N*K + 5*L + 8*I*J*K + 10.
If all cross sections are macroscopic, N is 1 above.

6. TYPICAL RUNNING TIME

The running  time of a problem  will depend
upon  the size  of the  problem,  the computer,  the compiler  and
operating system being used, and the amount of I/O required during
the iterative part of the  calculation.  The following table gives
the running  times and rates of  some typical problems run  on the
IBM360/75 computer using the IBM FORTRAN  IV compiler with Level 2
optimization and  operating system/360.   The machine  has a  512K
byte core memory plus 1024K bytes of large capacity storage.
    ----------------------------------------------------------
     Mesh size  Groups  2311 disk  No.iter.  Time(min)  Rate
    ----------------------------------------------------------
      31 x 31      3       no         83          3    0.0007
      42 x 25      9       no        151         17    0.0007
      31 x 81      9       no         92         28    0.0008
      51 x 51     25       yes       149        255    0.0016
    ----------------------------------------------------------

7. UNUSUAL FEATURES OF THE PROGRAM

EXTERMINATOR2 -
(a) Three outer-boundary conditions may be imposed - zero  flux, zero normal derivative, or periodic. The logarithmic  boundary condition may also be specified, either along         boundaries or internal to the mesh.
(b) Neutron scattering is allowed from any group to any other.  (c) Eigenvalue problems, constant source problems, poison  search problems, and nuclide density search problems may be  solved by direct iteration with the unknown treated as the  eigenvalue of the problem. Indirect search by solution of  succeeding eigenvalue problems is also included. Special  neutron problems can be solved in which some of the fluxes         are negative.
(d) The effect on the multiplication factor and the fluxes due  to pointwise equilibrium xenon concentrations may be taken         into account.
(e) The code will calculate adjoint fluxes and do perturbation         calculations.
(f) Flux-weighted broad-group microscopic cross sections may         be calculated.
(g) Succeeding cases require only those input data which are         different from the input from the preceding case.
(h) Optional output includes point-group fluxes as neutrons per  cm**2 -second, point neutron density as neutrons per cm**3,  point source density as fissions per cm**3 -second or  neutron productions per cm**3 -second, nuclide reaction  rates, total and composition neutron balances, and         cumulative heating along defined coolant channels.

8. RELATED AND AUXILIARY PROGRAMS

The original  IBM7090 version  of
EXTERMINATOR was prepared by T. B. Fowler, M. L. Tobias, and D. R.
Vondy  of Oak  Ridge National  Laboratory,  Oak Ridge,  Tennessee.
EXTERMINATOR2 is  a FORTRAN  IV version  of the  code EXTERMINATOR
with  major improvements.   EXTERMINATOR  was  developed from  the
slower few-group diffusion code, 20GRAND.

10. REFERENCES

- M.L. Tobias and T.B. Fowler:
  The EQUIPOISE Method - A Simple Procedure for Group-diffusion
  Calculations in Two and Three Dimensions
  Nuclear Science and Engineering, Vol.  12, pp. 513-518 (1962).
- T.B. Fowler, M.L. Tobias, and D.R. Vondy:
  EXTERMINATOR - A Multigroup Code for Solving Neutron Diffusion
  Equations in One and Two Dimensions
  ORNL-TM-842 (July 1966).
- R.L. Brunnenmeyer and R.A. Mickle:
  EXTERMINATOR-2 GE-625 Version (NE573) Users Note,
  Bechtel Note (July 1968).

- T.B. Fowler, M.L. Tobias and D.R. Vondy:
  EXTERMINATOR-2 A FORTRAN IV Code for Solving Multigroup Neutron
  Diffusion Equations in Two Dimensions
  ORNL-4078 (April 1967).

11. MACHINE REQUIREMENTS

A machine with a minimum of about 64K words of core storage and 5 I/O devices for temporary storage in addition to those for input data and printed output. Some problems may require 4 additional I/O devices.

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:  OS/360
(IBM360), GECOS (GE625), and SCOPE (CDC6600).

NEA-DB compiled the source program on a PC/80386 compatible desktop computer running under MSDOS 4.01 and using the Microsoft FORTRAN 5.0 compiler and executed the test case included in this package.

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

EXTERMINATOR2 can be made to conform to machines of different core
sizes simply by adjusting the fixed dimension of only one variable
in a  short master program.   The code  as compiled under  the IBM
FORTRAN IV compiler  on the IBM360 computer is  about 35,000 words
long but can  be shortened by as  much as one-half this  length by
removing some of  the subroutines which do  optional calculations.
Using  the overlay  feature of  the IBM360  operating system,  the
storage  requirements  can  be  reduced  to  about  15,000  words.
Because of storage limitations the GE625 version was shortened and
the following five subroutines were deleted -
   (1)  group rebalancing subroutine,
   (2)  neutron balance and reaction rate print subroutine,
   (3)  neutron absorption and density calculation subroutine,
   (4)  adjoint flux calculation subroutine, and
   (5)  channel heating calculations subroutine.

15. NAME AND ESTABLISHMENT OF AUTHORS

   360           T. B. Fowler, M. L. Tobias, and D. R. Vondy
                 Oak Ridge National Laboratory
                 P. O. Box X
                 Oak Ridge, Tennessee  37830
   625           R. L. Brunnenmeyer and R. A. Mickle
                 Bechtel Corporation
                 50 Beale Street
                 San Francisco, California  94119
   6600          Sam Pacino
                 Combustion Engineering, Inc.
                 P. O. Box 500
                 Windsor, Connecticut  06095

File name	File description	Records
NESC0156_06.001	Information file	68
NESC0156_06.002	Part 1 of EXTERMINATOR Source	308
NESC0156_06.003	Part 2 of EXTERMINATOR Source	1111
NESC0156_06.004	Part 3 of EXTERMINATOR Source	831
NESC0156_06.005	Part 4 of EXTERMINATOR Source	1131
NESC0156_06.006	Part 5 of EXTERMINATOR Source	850
NESC0156_06.007	Part 6 of EXTERMINATOR Source	1073
NESC0156_06.008	Part 7 of EXTERMINATOR Source	1127
NESC0156_06.009	Executable file	0
NESC0156_06.010	Sample input	66
NESC0156_06.011	Sample ouput	1304
NESC0156_06.012	DOS file-names	11