1. NAME AND TITLE
RSYST: Integrated Modular Code System for Shielding and Reactor Physics Calculations.
RSYST (Reactor System) was developed on the base of state-of-the-art European and American computing technology with unique features in the systems concepts. It was originally packaged in RSIC in the early 1970's This current version is RSYST-80.
2. CONTRIBUTOR
Nuclear Research Institute (IKE), Stuttgart Technical University, Stuttgart, Federal Republic of Germany, via OECD NEA Data Bank, Gif-sur-Yvette, France.
3. CODING LANGUAGE AND COMPUTER
FORTRAN IV and Assembler language; IBM 360/370.(C00269I036000)
4. NATURE OF PROBLEM SOLVED
RSYST is a modular system for reactor physics and shielding calculations. It consists of a system nucleus, utility modules, general data manipulation modules, reactor statics, burn-up and shielding calculation modules, a data base and fast and thermal cross section libraries based on ENDF/B-IV. The computational path is defined in the card input using user control commands.
5. METHOD OF SOLUTION
The RSYST system consists of a data base, a control section, a data base monitoring system, as well as an unlimited number of modules. The data transfer between individual modules is done through the data base monitoring program by way of the central data base. Control words of the input permit the user to control the processing of any desired modules. Each module can have flexible data input from the data base. By use of special modules, logical branches and loops can be carried out.
The computational modules solve several reactor physics problems by the following methods:
zero-dimensional spectrum calculations in the fast energy range by the Bn or Pl method;
zero-dimensional spectrum calculations in the thermal energy range by the Bn method;
calculation of fluxes in the resonance domain by the Nordheim or NR approximation;
calculation of group constants by the gas model;
homogenization and collapsing of group constants;
one-dimensional and two-dimensional neutron diffusion;
one-dimensional transport problems by the Sn method;
one-dimensional transport by the collision probability method;
burn-up equations with given flux conditions.
6. RESTRICTIONS OR LIMITATIONS
No dynamic storage allocation is used. Some modules have fixed dimensions, some a unique data array, whose length is defined at compilation time and depends on the available storage in the computer used.
7. TYPICAL RUNNING TIME
No study has been made by RSIC of typical running times for RSYST. The sample problems, demonstrating the use of almost all modules, take about 400 seconds CPU time on the IBM 360/91.
8. COMPUTER HARDWARE REQUIREMENTS
RSYST was originally designed for the CDC-6600. RSYST-80 is operable on IBM 360/370 computers. 800 K bytes of fast core is the size necessary if the single modules are run without overlay. For small applications this size can be reduced considerably. Disk drives are necessary for random access files.
9. COMPUTER SOFTWARE REQUIREMENTS
A FORTRAN IV compiler is required. Two small Assembler language routines are used: LOC returns address of a variable or vector; another routine is used to simulate ENCODE/DECODE on IBM.
10. REFERENCES
I. A. Bestrich, W. Gulden, K. Kubler, and R. Ruehle, "Implementation of the Program System RSYST on the IBM 370/168 of the GFK at Karlsruhe," ORNL-tr-2970 (IKE R No 4-35) (December 1974).
R. Ruehle, "RSYST, An Integrated Modular System with a Data Base for Automated Calculation of Nuclear Reactors," ORNL-tr-2796 (IKE-BNR-4-12) (July 1973).
R. Ruehle, "RSYSTShort Description of the Modules," IKE Report No. 4-5 (ORNL-tr-4193) (April 1976).
11. CONTENTS OF CODE PACKAGE
Included are the referenced documents and one DS/HD 3.5-in. (1.44 MB) diskette in DOS format which contains the source codes and sample problem input, plus output from the sample problems written in list format and output from the data library generation in binary form.
12. DATE OF ABSTRACT
October 1978; updated January 1983, December 1983; revised January 1985.
KEYWORDS: CROSS SECTION PROCESSING; MONTE CARLO; MODULAR SYSTEM; DISCRETE ORDINATES; NEUTRON; GAMMA-RAY; TWO-DIMENSIONS