RSICC CODE PACKAGE PSR-374

 

1.   NAME AND TITLE

MICROX-2:     Code System to Create Broad-Group Cross Sections with Resonance Interference and Self-Shielding from Fine-Group and Pointwise Cross Sections.

 

AUXILIARY PROGRAM

MICROR:         Reformatting program to produce cross sections from NJOY output files for use with MICROX-2 postprocessor codes.

 

2.   CONTRIBUTOR

Paul Scherrer Institut, Switzerland, through the Nuclear Energy Agency Data Bank, Issy-les-Moulineaux, France.

 

3.   CODING LANGUAGE AND COMPUTER

Fortran 95; PC Linux & Windows (P00374/MNYCP/02).

 

4.   NATURE OF PROBLEM SOLVED

RSICC received MICROX‑2 through the NEADB (identifier is NEA‑1562/02.) This is an improved version of the original MICROX-2 two-region spectrum code, which was developed at General Atomic, to prepare broad group neutron cross sections for use in diffusion-and/or transport theory codes from an input library of fine group and pointwise cross sections.  The MICROX-2 code can explicitly account for the overlap and interference effects between resonances in both the resonance and thermal neutron energy ranges and allows the simulta­neous treatment of leakage and resonance self-shielding in doubly heterogeneous lattice cells. 

MICROR runs as a module of NJOY 89.62; the NJOY calling module is included in the package. This release has been changed in that the MODER module from NJOY 94.0, too, has been included as subprogramm of NJOY 89.62, so as to make the code system completely selfconsistent, i.e. without requiring the use of some NJOY version to convert pendf and gendf from coded to binary.

Using data from pointwise and groupwise NJOY tapes, the stand-alone MICROR reformatting program produces files containing basic nuclear data to be used by MICROX-2. MICROR edits PENDF and GENDF data files from NJOY to create FDTAP­E, GGTA­PE and GARTA­PE input files for MICROX-2.  NJOY is not included in this package. Some data libraries are included for example cases; these data were generated from data in 193 groups as well as from point-wise cross sections from NJOY (Edition 89.62).

 

5.   METHOD OF SOLUTION

The neutron weighting spectrum is obtained by solving the B1 neutron balance equations at about 10000 energies in a one-dimensional (planar, spherical, or cylindrical), two-region unit cell.  Regions are coupled by collision probabilities based upon spatially flat neutron emission. Energy dependent Dancoff factors and bucklings correct the one-dimensional cell calculations for multi-dimensional lattice effects. A critical buckling search option is also included. The inner region may include two different types of fuel particles (grains). 

 

6.   RESTRICTIONS OR LIMITATIONS

The previous release was developed on 64-bit computers, but this release was adapted to 32-bit.

 

7.   TYPICAL RUNNING TIME

The codes were tested at the NEA Data Bank and at RSICC. Utility test cases ran in a few seconds, but gendf_to_bin and pendf_to_bin may require tens of seconds; MICROR1 and MICROR2 test cases: less than 1 minute; MICROX-2 cases: few seconds.

 

8.   COMPUTER HARDWARE REQUIREMENTS

The codes run on 32-bit personal computers.

 

9.   COMPUTER SOFTWARE REQUIREMENTS

MICROX-2 runs on PC Intel under Linux or Windows operating systems. The NEADB tested on these systems under WINDOWS XP Professional with Lahey/Fujitsu Fortran 95 Compiler Release 5.50d (lf95) and under SuSE linux 7.2 kernel 2.4.4 with Lahey/Fujitsu Fortran 95 Compiler Release 6.10a (lf95). RSICC tested under WindowsXP and Windows Vista with lf95 (versions 5.50d) and under RedHat Linux 7.3 with Lahey-Fujitsu lf95 vL6.10a. All programs must be compiled with the Lahey/Fujitsu options -long -dbl option. No executables are included in the package, so a Fortran compiler is required.

 

10. REFERENCES

D. Mathews, “An Improved Version of the MICROX-2 Code,” PSI Bericht Nr. 97-11 (November 1997).

D. Mathews, “Appendices B to E of PSI-Report No. 97-11: ‘An Improved Version of the MICROX-2 Code,’” TM-41-97-17 (November 1997).

D. Mathews, J. Stepanek, S. Pelloni, and C.E. Higgs, “The NJOY Nuclear Data Processing System: The MICROR Module,” EIR-Beiricht Nr. 539 (December 1984).

 

11. CONTENTS OF CODE PACKAGE

Included are the referenced documents, Fortran source codes, makefiles, data files, sample problem input and output. The package is transmitted on CD-ROM in a Linux compressed tar file, which can be extracted with WinZIP on Windows.

 

12. DATE OF ABSTRACT

January 1999, revised September 2002, October 2007.

 

KEYWORDS:   CROSS SECTION PROCESSING; ENDF FORMAT; REACTOR PHYSICS; WORKSTATION; MICROCOMPUTER