1. NAME AND TITLE

PREMOR: A Point Reactor Exposure Code System for Survey Nuclear Analysis of Power Plant Performance.

2. CONTRIBUTOR

Oak Ridge National Laboratory, Oak Ridge, Tennessee.

3. CODING LANGUAGE AND COMPUTER

Fortran IV; IBM 360/370.

4. NATURE OF PROBLEM SOLVED

PREMOR is a point reactor exposure model code for survey nuclear analysis of power plant performance. It was written to exploit a simple, two-group point nuclear reactor power plant model for survey analysis. Up to thirteen actinides, fourteen fission products, and one lumped absorber nuclide densities are followed over a reactor history. Successive feed batches are accounted for with provision for from one to twenty batches resident. The effect of exposure of each of the batches to the same neutron flux is determined.

The code has been used extensively for analysis of the graphite moderated, gas-cooled reactor concept.

5. METHOD OF SOLUTION

The requirements for a critical system and desired power level are satisfied by a direct iteration procedure that adjusts the actinide feed composition as necessary. Elaborate edits report such results as the neutron absorption distribution, nuclide concentrations, fuel cost and ore requirements, and such integral information as the simple fuel conversion ratio and doubling time, fuel consumption rate, effective neutron production per absorption and reactivity importance of the nuclides, at selected points in the history. Nested loops are used to follow the reactor history with delayed recycle and direct iteration to required feed conditions to satisfy the critical state. Only the essential amount of calculation is done to produce adequate results for parameter studies at a low cost of computation. Iteration may be done to an optimum fuel cost, or succeeding problems solved to vary the neutron loss fraction.

6. RESTRICTIONS OR LIMITATIONS

None noted.

7. TYPICAL RUNNING TIME

Reactor histories are done in a few seconds of IBM 360/91 computer time.

8. COMPUTER HARDWARE REQUIREMENTS

PREMOR is operable on the IBM 360/370 computers. A 68,000 short word memory is needed for the compile step.

9. COMPUTER SOFTWARE REQUIREMENTS

A Fortran H level compiler version 21.8 is required. The operating system used is the IBM OS-360 under HASP.

10. REFERENCE

D. R. Vondy, "PREMOR: A Point Reactor Exposure Model Computer Code for Survey Analysis of Power Plant Performance," ORNL-5580 (October 1979).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one (1.2MB) DOS diskette which contains the source codes and sample problem input and output.

12. DATE OF ABSTRACT

February 1982.