NEA-0160 COSTANZA-AX-CYL.

1. NAME OR DESIGNATION OF PROGRAM:  COSTANZA-CYL, COSTANZA-AX.

3. NATURE OF PHYSICAL PROBLEM SOLVED

Purpose of the programmes is to study reactor dynamics, considering the variation of the spatial flux distribution. The two programmes COSTANZA-CYL and COSTANZA-AX,  solve the kinetics diffusion equations in two groups and one dimension (plane geometry for COSTANZA-AX, radial geometry for COSTANZA-CYL). The neutronic calculation is coupled with the calculation of the heat transmission from the fuel to the cladding and to the coolant, and with the thermo-hydraulics of channels with  forced circulation of liquid coolant. The geometry of fuel element and channel may be cylindrical or slab. Up to ten groups of delayed  neutrons are allowed. Temperature feedback of fuel (Doppler) and coolant are considered independently and affect the nuclear constants. Control rod movement or diffused poison concentrations are simulated by externally imposed variations of the thermal absorption cross section in the different regions of the reactors. Inlet temperatures and mass flow in the coolant channels may be varied according to any externally given time table.

4. METHOD OF SOLUTION

The kinetic diffusion equations in two groups are solved by finite-difference method.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

   10 concentric regions
   10 coolant channels
   10 groups of delayed neutrons

6. TYPICAL RUNNING TIME

For average problems of 50 mesh-points one to two minutes will be required for every 1000 time steps.

7. UNUSUAL FEATURES OF THE PROGRAM

The thermal resistance of the gap between fuel and clad and the heat transfer coefficient at every axial level of the channel are variable functions of thermodynamics  parameters. In the initialization of each problem criticality may be searched for by varying poison insertion in any wanted zone. A free  test routine may be used to insert new specifications when any wanted conditions are reached during the transients.

8. RELATED OR AUXILIARY PROGRAMS: RELATED AND AUXILIARY PROGRAMS

10. REFERENCES

- A. Agazzi, G. Forti, E. Vincenzi:
  COSTANZA CYLINDRICAL A Cylindrical One-Dimensional Dynamics Code for Liquid-Cooled Multi-Channel Nuclear Reactors
  EUR. 3171E (1966).

- G. Forti and E. Vincenti:
  The codes COSTANZA for the Dynamics of Liquid-Cooled Nuclear
  Reactors.  EUR 3633e  (1967)
- G. Forti and E. Vincenti:
  The Codes COSTANZA for the Dynamics of Liquid-Cooled Nuclear
  Reactors.  EUR 3633e  (1967)

11. HARDWARE REQUIREMENTS: MACHINE REQUIREMENTS

13. OPERATING SYSTEM OR MONITOR UNDER WHICH PROGRAM IS EXECUTED:  IBM 360/65 Operating System.

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

ANY OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

15. NAME AND ESTABLISHMENT OF AUTHOR

     A. Agazzi, G. Forti, E. Vincenti
     Commission des Communautes Europeennes
     21020 - Ispra (Varese)
     Italy

File name	File description	Records
NEA0160_01.001	SOURCE & DATA 360/65	1352
NEA0160_01.002	OUTPUT	755

File name	File description	Records
NEA0160_02.001	Information file	32
NEA0160_02.002	COSTANZA-CYL source (FORTRAN) + input data	1281
NEA0160_02.003	COSTANZA-CYL printed output	535