NEA-0684 SSYST-3.

1. NAME OR DESIGNATION OF PROGRAM:  SSYST-3

3. DESCRIPTION OF PROBLEM OR FUNCTION

SSYST is a code system for analyzing transient fuel rod behaviour under off-normal conditions,  developed jointly by the Institut fuer Kernenergetik und Energie- systeme (IKE), Stuttgart, and Kernforschungszentrum Karlsruhe (KfK)  under contract for the Projekt Nukleare Sicherheit (PNS) at KfK. Main differences versus codes with similar applications are:

   (1) an open-ended modular code organisation
   (2) a preference for simple models, wherever possible.

While feature (1) makes SSYST a very flexible tool, easily adapted to changing requirements, feature (2) leads to short execution times. The analysis of transient rod behaviour under LOCA boundary conditions takes 2 minutes CPU time on IBM 3033, so that extensive parametric studies are feasible.

Main differences between SSYST-3 and previous versions are related to a general clean-up of the code system, which reduces the implementation effort:
- advanced modules for cladding deformation and oxidation and   reflooding conditions are included;
- an input processor thoroughly checks all input data.

4. METHOD OF SOLUTION:

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM:

6. TYPICAL RUNNING TIME

The analysis of transient rod behaviour under LOCA conditions takes 2 minutes of CPU time on IBM 3081.

The sample problems supplied with the package each take under 9 seconds of CPU time on IBM 3084.

7. UNUSUAL FEATURES OF THE PROGRAM:

8. RELATED AND AUXILIARY PROGRAMS:

10. REFERENCES

- S. Raff: Report KfK 3184 (1982)
- S. Raff, R. Meyder:
  "NORA-2, A Model for Creep Deformation and Rupture of Zircaloy at
   High Temperatures"
  in:
  J. Grittus, Ed.
  "Water Reactor Fuel Element Performance Computer Modelling"
  Applied Science Publ., Barking 1983
- "A Probabilistic SSYST-3 Analysis of a PWR Large Break LOCA"
  KfK 3873 (to be published). In German
- E.J. Kersting:
  "Code REFLOS, A Program for Refill and Reflood Calculations"
  GRS-A-163 (September 1978) In German

- R. Meyder:
  "SSYST-3, Input Description and Handling"
  KfK 3654 (December 1983). In German
- H. Borgwaldt, W. Gulden:
  "SSYST, A Code System for Analysing Transient LWR Fuel Rod
  Behaviour Under Off-Normal Conditions"
  KfK 3359 (June 1982)
- H. Borgwaldt, et al.:
  "The Code System SSYST, Present Status and Current Development"
  Paper submitted to the Technical Committee/Workshop on the IAEA
  Programme in the Use of Computer Codes for Safety Analysis,
  Varna, Bulgaria, 28 May - 1 June 1984
- H. Borgwaldt:
  "PREPRO, A Preprocessor Code for SSYST Input"
  KfK 3537 (May 1983)
- W. Sengpiel:
  "SSYST-3 Module DESIGN"
  PNS-Nr. 605/81 (July 1981). In German
- W. Sengpiel:
  "SSYST-3 Module REGRES"
  PNS-Nr. 606/81 (July 1981). In German
- W. Sengpiel:
  "SSYST-3 Module MOCA"
  PNS-Nr. 607/81 (July 1981). In German
- S. Malang:
  "Code MULTRAN to Calculate High-Temperature Water-Vapour Zircaloy
  in Fuel Cladding of Water-Cooled Reactors"
  PNS-Nr. 750/83 (July 1983). In German
- J. Linek:
  Modelling of WWER Type Fuel Rods with the SSYST Code.
  Reprint from "Kernenergie", 30(1987)5, 189-192

11. MACHINE REQUIREMENTS:

Main storage requirements for running the test cases included in the package are less than 500K bytes on IBM 3084Q.

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED

MVS-SP (IBM 3084).
Compilers: FORTRAN-H-EXTENDED Version 2.3.0
           ASSEMBLER-H Version 0.5
           PL/I.

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:

15. NAME AND ESTABLISHMENT OF AUTHOR

W. Gulden, Projekt Nukleare Sicherheit
R. Meyder, Institut fuer Reaktorentwicklung
H. Borgwaldt, Institut fuer Neutronenphysik und Reaktortechnik
Kernforschungszentrum Karlsruhe GmbH
Postfach 3640
D-7500 KARLSRUHE, F.R. of Germany

File name	File description	Records
NEA0684_06.001	Information File	165
NEA0684_06.002	JCL to generate PDS files	44
NEA0684_06.003	NUCLEUS source program (FORTRAN-IV)	4405
NEA0684_06.004	SERVICE source program (FORTRAN-IV)	5631
NEA0684_06.005	PHYSICS source program (FORTRAN-IV)	26787
NEA0684_06.006	Control JCL & data	415
NEA0684_06.007	PREPRO source program (PL/I)	2736
NEA0684_06.008	MATPRO material properties lib (bin)	5
NEA0684_06.009	Test case JCL & data	1741
NEA0684_06.010	NEWBASIS test case printed output	437
NEA0684_06.011	COMPLETE test case printed output	55
NEA0684_06.012	SAMPLE1 test case printed output	160
NEA0684_06.013	SAMPLE2 test case printed output	119
NEA0684_06.014	SAMPLE3 test case printed output	702
NEA0684_06.015	SAMPLE4 test case printed output	1615
NEA0684_06.016	PREPROA test case printed output	283
NEA0684_06.017	PREPROB test case printed output	95