1. NAME AND TITLE

FPZD: Code System for Multigroup Neutron Diffusion/Depletion Calculations.

2. CONTRIBUTOR

Marshall Space Flight Center, NASA, Huntsville, Alabama.

3. CODING LANGUAGE AND COMPUTER

FORTRAN 77; PC 386 and PC 486.

4. NATURE OF PROBLEM SOLVED

FPZD calculates the spatial power and neutron flux distributions of a nuclear reactor along with its effective multiplication factor and time-dependent material compositions.

5. METHOD OF SOLUTION

The depletion subroutines permit a very generalized nuclide depletion scheme to be used in which the materials may be distributed into a number of burnup subregions each containing a different atom density set. Depletion of the nuclides is calculated separately for each burnup subregion assuming exposure to the average flux of the spatial region. The macroscopic properties of a spatial region are calculated by giving the appropriate volume fraction weighting factors to the cross sections of the burnup subregions.

6. RESTRICTIONS OR LIMITATIONS

Non noted.

7. TYPICAL RUNNING TIME

On a 20 megahertz PC 386 with a math co-processor, the following times were noted: FPZDIN.INI took 45 minutes; FPZDIN.KIC took 25 minutes; FPZDIN.IC took 35 minutes; FPZDIN.KRL took 45 minutes; FPZDIN.RL took 40 minutes.

8. COMPUTER HARDWARE REQUIREMENTS

FPZD runs on the PC 386 or PC 486 under the DOS 5.0 operating system; a math co-processor is required.

9. COMPUTER SOFTWARE REQUIREMENTS

The code was written in FORTRAN 77 and was tested using the Microsoft Version 5.01 compiler.

10. REFERENCES

B. Emmrich, "A One-Dimensional Multigroup Neutron Diffusion/Depletion Code for Performing Control and Fuel Loading Searches and for Determining the Fuel and Poison Distributions Required to Achieve Burnup Independent Power Distributions with Optional Thermal-Fluid Feedback," NASA informal document, Marshall Flight Center, Huntsville, Alabama.

11. CONTENTS OF CODE PACKAGE

Included are the referenced documents and 3 5.25-inch DS/HD (1.2MB) diskettes which include source and executable codes, sample input and output.

12. DATE OF ABSTRACT

June 1992.