1. NAME AND TITLE

TIBSO: Code System to Calculate Production and Migration of Radionuclides in Nuclear Reactor Systems.

2. CONTRIBUTOR

KFKI Atomic Energy Research Institute, Budapest, Hungary.

3. CODING LANGUAGE AND COMPUTER

Fortran -77; PC DOS, VAX/VMS, RISC/6000 (C00512/MNYCP/00).

4. NATURE OF PROBLEM SOLVED

TIBSO follows the nuclear transition and the spatial migration of radioactive models. The modeling of such processes is established in a very flexible way enabling the user to investigate a wide range of problems. Nuclear data libraries from CCC-371/ORIGEN2 are included. Libraries for structural, fission product, and actinide materials are provided as part of the package. Coupling with thermohydraulic codes like RELAP and CONTAIN, it can be used for calculation of radioactive release in the case of nuclear accidents. Its output can be used to environmental codes like CRAC2.

5. METHOD OF SOLUTION

The spatial migration is modeled by transition between nodes. The system of first order linear differential equations describing the nuclear decay and activation process and the transitions between nodes is solved by step-wise numerical integration.

6. RESTRICTIONS OR LIMITATIONS

Due to dynamic programming techniques only the available storage can restrict the number of isotopes and nodes.

7. TYPICAL RUNNING TIME

Running times are highly dependent on the complexity of the system being modeled. Depending on the complexity (number of nodes, number of isotopes, length of the process), from some minutes up to two hours on a 486/33MHz PC.

8. COMPUTER HARDWARE REQUIREMENTS

TIBSO has run on PC-386, Vax, and IBM RS/6000 workstations.

9. COMPUTER SOFTWARE REQUIREMENTS

TIBSO runs under AIX, VMS, or DOS. A Fortran 77 compiler is required. It was tested at RSIC on a Northgate 486/66 running MS-DOS v6.2 using MS Fortran v5.0.

10. REFERENCES

a. Included in documentation:

P. Vertes, Informal Report, "Code for Calculation of Spreading of Radioactive Materials in Complicated Systems (TIBSO code)," (1994).

P. Vertes, Informal Report, "Some Problems of Activity Migration Solved with TIBSO," (1994).

b. Background information:

P. Vertes, "Code for Calculation of Spreading of Radioactivity in Reactor Containment Systems, (TIBSO code)," KFKI-1992-27/G (September 1992).

11. CONTENTS OF CODE PACKAGE

Included are the referenced documents and 1 (1.44 MB) DOS diskette in self-extracting compressed DOS files which contains the source code, data libraries, sample problem input, plus output from the sample problem.

12. DATE OF ABSTRACT

July 1987, revised January 1991, March 1995.