1. NAME AND TITLE

REX2-87: A Code For Calculating Self-Shielded Multigroup Neutron Cross Sections and Self-Shielding Factors From Preprocessed ENDF/B Basic Data Files

2. CONTRIBUTOR

Indira Gandhi Center for Atomic Research, India, through NEA Data Bank, France.

3. CODING LANGUAGE AND COMPUTER

Fortran IV; VAX 8810.

4. NATURE OF PROBLEM SOLVED

REX2-87 is a computer code developed for the calculation of self-shielded multigroup average cross sections, and self-shielding factors for total, elastic, fission and capture processes from an ENDF/B formatted nuclear data file in which the tabulated cross sections follow linear interpolation throughout.

5. METHOD OF SOLUTION

The linearly interpolated tabulated cross sections are normally obtained with the preprocessing codes RECENT, LINEAR, SIGMA1 (see PSR-159). REX2-87 is applied on the output of the SIGMA1 code which gives the Doppler broadened point cross sections so that self-shielded average cross sections and the associated self-shielding factors can be obtained corresponding to the temperature to which the point cross sections refer. The code calculates by default the averages in the resolved resonance region.

6. RESTRICTIONS OR LIMITATIONS

The maximum number of energy groups is 620.

7. TYPICAL RUNNING TIME

The sample input problems were tested at NEA Data Bank on a Vax 8810 computer. The total time was 85 CPU seconds.

8. COMPUTER HARDWARE REQUIREMENTS

REX2-87 runs on the VAX 8810.

9. COMPUTER SOFTWARE REQUIREMENTS

The code was written in Fortran IV. The NEA Data Bank used the VAX Fortran (version 5.0) under the VAX/VMS operating system.

10. REFERENCE

V. Gopalakrishnan, and S. Ganesan, "REX2-87, A Code for Calculating Self-Shielded Multigroup Neutron Cross Sections and Self-Shielding Factors From Preprocessed ENDF/B Basic Data File," IGCAR/NDS-18 (IAEA 0935) (November 1988).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one DS/HD (1.2 MB) 5.25-inch diskette.

12. DATE OF ABSTRACT

November 1990.