NESC0310 GAKIN2

1. NAME OR DESIGNATION OF PROGRAM:  GAKIN2

3. DESCRIPTION OF PROBLEM OR FUNCTION

GAKIN2 solves    the    time-
dependent  multigroup neutron  diffusion  equations  in one  space
dimension.

4. METHOD OF SOLUTION

The  space  dimension is  treated  using  the
conventional finite difference approximation.  Time integration is
accomplished using an exponential transformation and semi-implicit
differencing.   The  resulting  equations   are  solved  by  first
predicting  the frequency  for the  time  transformation and  then
correcting the solution by solving the full set of equations.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

Variable
dimensioning permits accommodation of any number of energy groups,
space points, and material regions, within the limits of available
storage.  The  number of delayed neutron  groups is limited  to 6.
The number  of bytes allocated for  data storage is a  function of
the dimension of COMMON block A.  The size of A, which is also the
value of the variable MAX, must be greater than
           8(P(G+D) + 2GD + 10G + G(G+1) + 25R
            + 19RG + RG**2 + 11P + 4PG + 2N + 50)
where
   R is the number of regions,
   G is the number of neutron energy groups,
   D is the number of delayed neutron groups,
   P is the number of space points, and
   N is the number of test points for testing convergence and
     predicting transformation frequencies (recommended value is
     one or two times the number of material regions, R).

6. TYPICAL RUNNING TIME

Computation time  per problem  time-step is
roughly approximated by  (2 * 10**(-4)) * (P(G +  0.3D)), where P,
G,  and D  are defined  as in  item  5 above.   NESC compiled  and
executed the sample problems in less than 2 minutes of CPU time on
an IBM370/195.

7. UNUSUAL FEATURES OF THE PROGRAM

GAKIN2  permits  an  arbitrarily
large number of neutron energy groups.

8. RELATED AND AUXILIARY PROGRAMS

GAKIN2 is a revision of the GAKIN
code  with  improved  temporal  treatment.   The  original  IBM370
version  of GAKIN2  was submitted  by John  W. Mason  and Kent  F.
Hansen of the Massachusetts Institute of Technology.

10. REFERENCES

J. H.  Mason  and K.  F.  Hansen,  GAKIN II,  A  One-
dimensional  Multigroup Diffusion  Theory  Reactor Kinetics  Code,
MITNE-151, August 1973.
             E.  T.  Dugan,  Errata  MITNE-151,  NESC  Note  79-9,
GAKIN2, December 6, 1978.
             K. F.  Hansen  and  S.  R.  Johnson,  GAKIN,  A  One-
dimensional Multigroup Kinetics Code, GAMD-7543, August 1967.

  - J. H. Mason, and K. F. Nansen;
    GAKIN II: A One-Dimensional Multigroup Diffusion Theory Reactor
    Kinetics Code. COO-2262-3 MITNE-151 (August 1973).
  - K. F. Hansen, and S. R. Johnson;
    GAKIN: A One-Dimensional Multigroup Kinetics Code. GA-7543
    (August 24, 1967).

11. MACHINE REQUIREMENTS:  275K bytes of storage on an IBM370/195

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:  OS/370.

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:

15. NAME AND ESTABLISHMENT OF AUTHOR

   Contact       E. T. Dugan
                 Department of Nuclear Engineering Sciences
                 University of Florida
                 202 Nuclear Sciences Center
                 Gainesville, Florida  32611

File name	File description	Records
NESC0310_03.002	SOURCE PROGRAM (F4,EBCDIC)	2579
NESC0310_03.003	SAMPLE PROBLEM INPUT DATA (CASE 1)	60
NESC0310_03.004	SAMPLE PROBLEM INPUT DATA (CASE 2)	62
NESC0310_03.005	SAMPLE PROBLEM PRINTED OUTPUT (CASE 1)	617
NESC0310_03.006	SAMPLE PROBLEM PRINTED OUTPUT (CASE 2)	908