RSICC CODE PACKAGE PSR-505

1. NAME AND TITLE

MOSRA-LIGHT 98.7: High Speed Three-Dimensional Nodal Diffusion Code System.

2. CONTRIBUTORS

Department of Nuclear Energy System, Japan Atomic Energy Research Institute, Tokai-mura, Japan, through the OECD NEA Data Bank, Issy-les-Moulineaux, France.

3. CODING LANGUAGE AND COMPUTER

FORTRAN-77/FORTRAN-90, UNIX workstations, and Linux PC (P00505MNYWS00).

4. NATURE OF THE PROBLEM SOLVED

MOSRA-Light is a three-dimensional diffusion calculation code for X-Y-Z geometry. It can be used in: validation of discontinuity factor for adjoint problem; benchmark on discontinuity factor (forward & adjoint cal.); DVP BWR Benchmark (2D,2G calculation); and void reactivity effect benchmark; etc. A utility code called More-MOSRA provides many useful functions with the file produced by MOSRA-Light.

5. METHOD OF SOLUTION

MOSRA-Light is based on the 4th order polynomial nodal expansion method (NEM). As the 4th order NEM is not sensitive to mesh sizes, accurate calculation is possible by the use of coarse meshes of about 20 cm. The drastic decrease of number of unknowns in a 3-dimensional problem results in very fast computation. Furthermore, it employs newly developed computation algorithm "boundary separated checkerboard sweep method" appropriate to vector computers. This method is very efficient because the speedup factor by vectorization increases, as a scale of problem becomes lager. Speed-up factor compared to the scalar calculation is from 20 to 40 in the case of PWR core calculation. Considering both effects by the vectorization and the coarse mesh method, total speedup factor is more than 1000 as compared with conventional scalar code with the finite difference method. The general theory of NEM, the fast computation algorithm, benchmark calculation results and detailed information for usage of this code including input data instruction and sample input data is described in the documentation.

6. RESTRICTIONS OR LIMITATIONS

None noted.

7. TYPICAL RUNNING TIME

Both MOSRA-Light and its utility More-MOSRA were installed and tested on SUN Solaris Workstation. It takes about 10 sec to run the test sample Test.sh file for MOSRA_Light. (Test.sh is an IAEA3D benchmark problem (2-group eigenvalue problem), where, Mesh size = 20cm (1*1/Fuel Assembly) with diagonal symmetric option.) Less than 10 sec is required to run Detector.sh for More-MOSRA utility, the Detector.sh is for determining Detector Reaction Rate in IAEA3D benchmark problem.

8. COMPUTER HARDWARE REQUIREMENTS

MOSRA-Light can be installed on most of the machines whose OS type is UNIX or similar ones (Linux, FreeBSD) with FORTRAN compilers (FORTARAN77 / FORTAN90).

9. COMPUTER SOFTWARE REQUIREMENTS

MOSRA-Light has been tested on several computers running Unix and RedHat Linux 4.2. All source programs of MOSRA-Light are written by FORTRAN77 except for some miner subroutines for personal computers. A Fortoran comiler is required on all systems. A C compiler is used to get date, time, and CPU time. As these functions are not essential for MOSRA-Light calculation, a C compiler is not indispensable. No executables are included in this package. RSICC tested MOSRA-Light on a SUN UltraSparc 60 under SunOS 5.6 with f77 version 5 and C version 5.0 compilers. The code was tested at JAERI on the following systems:

HP 9000/735 : HP-UX9.07

SUN Sparc 20 : SunOS 4.1.3 (Sparc 3.0, Sola.1.1)

IBM AIX RS/6000 : AIX

HITACHI SR-2201 : HI-UX/MPP (FORTRAN77/FORTRAN90)

FACOM AP-3000 : UltarSPARC (Solaris 2.5.1)

FACOM VPP500/42 : UXP/M

FACOM VPP300 : UXP/V

Monte4(NEC SX3) : SUPER-UX

SX4 (NEC) : SUPER-UX

CRAY/T94 : UNICOS Ver 9.0 (FORTRAN77/FORTRAN90)

Pentium-II Linux(redhatV4.2) (f2c + gcc)

Pentium-II Linux(redhatV4.2) (f2c + g77)

10. REFERENCES

a) Included in document:

K. Okumura, "MOSRA-Light: High Speed Three-Dimensional Nodal Diffusion Code for Vector Computers," JAERI-Data/Code 98-025 (September 7, 1998).

Readme.txt by RSICC (March 2001).

b) Background information:

K. S. Smith, "Assembly Homogenization Techniques for Light Water Reactor," Progress in Nuclear Energy, Vol.3, pp303-335 (1986).

11. CONTENTS OF CODE PACKAGE

Included are the referenced documents in (10.a) and a diskette which contains a GNU compressed tar file, which is about 0.25 MB. The required disk space for MOSRA-Light after installation is about 3.5 MB including the utility code More-MOSRA. The distribution includes source, an installer, 2 test cases, and electronic help files.

12. DATE OF ABSTRACT

March 2001.

KEYWORDS: COMPLEX GEOMETRY; DIFFUSION THEORY; LWR.