1. NAME AND TITLE

FPIC: Fission Product Inventory Code

2. CONTRIBUTOR

Nuclear Analysis Department, Lockheed-Georgia Company, Marietta, Georgia

FPIC is retained by RSIC as an early version of a family of similar codes. Newer technology is available During 19661979, it was distributed by RSIC 16 times.

3. CODING LANGUAGE AND COMPUTER

FORTRAN; IBM 360/370

4. NATURE OF PROBLEM SOLVED

Fission product gamma-ray sources in reactors are computed for any later heating or shielding calculation.

FPIC computes, as a function of reactor operation and shutdown time, the total decay rate, the total average beta energy release rate, total gamma energy release rate, and gamma energy release rate for each of seven energy groups from fission products generated in a U-235 thermal reactor. In addition, the program calculates the decay rate in curies and the lifetime (70 year) dose (resulting from total inhalation) in rem to twelve body organs as a function of decay time for each individual isotope and sums the inhalation dose over all isotopes for each organ and decay time.

5. METHOD OF SOLUTION

The program treats a doubly cyclic reactor operating schedule which may easily be specialized to the simpler case of a single operation period including instantaneous operation. The basic system of differential equations which describe the decay-buildup process for each mass chain was modified to treat the various possibilities considered in this treatment and rewritten in a form suitable for direct solution.

Efforts were made in this code version to compile input data from the best available decay schemes for all fission product nuclides with half-lives greater than 10 seconds and fission yields greater than 0001%. Data were compiled for 190 isotopes including metastable states

6. RESTRICTIONS OR LIMITATIONS

The packaged nuclear data library will handle up to 200 nuclides but may be extended to a larger number. Up to 55 decay times may be handled.

7. TYPICAL RUNNING TIME

Running time per case is less than ten seconds if no individual isotope data are requested; including this request for the entire isotope library lengthens the running time to about two minutes.

8. COMPUTER HARDWARE REQUIREMENTS

Designed for an IBM 7090 or 7094 computer, FPIC runs on the IBM 360/370 The code uses three tape units.

9. COMPUTER SOFTWARE REQUIREMENTS

FPIC was written for the IBM FORTRAN II Monitor System and now runs on FORTRAN IV systems. Only input, output, and system tape assignments are made.

10. REFERENCE

K. O. Koebberling, W. E. Krull, J. H. Wilson, Lockheed Fission Product Inventory Code, ER-6906 (May 1964).

11. CONTENTS OF CODE PACKAGE

The package contains the referenced document, a reel of magnetic tape on which is written in separate files: the BCD source card deck, input for a sample problem, and output from the problem; total records 2462.

12. DATE OF ABSTRACT

January 1966; updated July 1981, February 1985.

KEYWORDS: FISSION PRODUCTS; GAMMA-RAY; FISSION PRODUCT INVENTORY