1. NAME AND TITLE

WIMS-D4: Winfrith Improved Multigroup Scheme Code System.

2. CONTRIBUTORS

Atomic Energy Establishment, Winfrith, Dorchester, through NEA Data Bank, Gif-sur-Yvette Cedex, France.

Technical University of Prague, Prague, Czechoslovakia, through NEA Data Bank.

Institute of Atomic Energy, Poland, through NEA Data Bank.

McMaster University, Hamilton, Ontario, Canada.

3. CODING LANGUAGE AND COMPUTER

FORTRAN 77; IBM 3090, VAX 8810 (A: C00576/ALLMF/00; NEA 329/13); PC 386 (B: C00576/PC386/00; NEA 329/14); IBM PC/AT (C: C00576/IPCAT/00; NEA 329/16); IBM PC and PC 386 (D: C00576/IBMPC/00; NEA 329/15).

4. NATURE OF PROBLEM SOLVED

WIMS-D4 is a general lattice cell program which uses transport theory to calculate flux as a function of energy and position in the cell.

5. METHOD OF SOLUTION

WIMS-D4 first calculates spectra for a few spatial regions in the full number of energy groups of its library, and uses these spectra to condense the basic cross-sections into few groups. A few group calculation is then carried out using a much more detailed spatial representation. The resulting fluxes are then expanded using the spectra of the previous calculation, so that the reaction rates at each spatial point can be calculated in the library group structure.

A variety of geometries can be treated. The basic ones are: homogeneous, slab array, regular rod arrays, rod-clusters in cylindrical geometry and finite cylinders in r-z geometry. In addition to the basic cell calculation, the program may be used to carry out burnup calculations and to solve multicell problems.

WIMS-D4 reads the basic microscopic cross-sections from its library tape. From these it calculates the macroscopic cross sections for each material, with resonance shielding being normally automatically calculated. The preliminary spectrum calculation (many groups, few regions) is carried out using collision probability methods, while for the main transport calculation (many regions, condensed groups) there is an option to use either collision probability methods or WDSN.

A 69-group data library is included.

6. RESTRICTIONS OR LIMITATIONS

Variable dimensioning is used in the code.

7. TYPICAL RUNNING TIME

On the IBM 3090, the test cases varied in run times between 1.34 and 30.58 seconds; on the VAX 8810, they were between 5 and 58 seconds. These runs were carried out at NEA Data Bank.

8. COMPUTER HARDWARE REQUIREMENTS

WIMS-D4 (A:C00576/ALLMF/00) runs on the VAX 8810 and IBM 3090.

The (B:C00576/PC386/00) version runs on a PC 386 with 640 K main memory, a minimum of 1 megabyte of extended memory, a math co-processor and a hard disk.

The (C: C00576/IPCAT/00) version runs on an IBM PC/AT with 640 K of memory and a math coprocessor.

The (D: C00576/IBMPC/00) version runs on an IBM PC and PC 386 with 640 K of memory and extended memory of about 1 MB.

9. COMPUTER SOFTWARE REQUIREMENTS

The code was written in FORTRAN 77. On the IBM 3090, VS FORTRAN 2.1.1 was used under the MVS/XA operating system. On the VAX 8810, VAX FORTRAN under VAX/VMS 5.0-1 was used.

On the (B: C00576/PC386/00), NDP-FORTRAN-386 version 1.4vm, Phar Lap 386LINK linker version 2.0, Phar Lap RUN386 version 2.0, Phar Lap 386ASM assembler version 2.0 and Phar Lap 386 VMM driver for 386 were used under the MS-DOS version 3.2 operating system.

On the IBM PC/AT (C: C00576/IPCAT/00), Microsoft FORTRAN Version 5.0 was used under the DOS 3.2 operating system.

On the IBM PC and PC 386 (D: C00576/IBMPC/00), Microsoft FORTRAN Version 4.1 was used under the DOS 3.2 operating system.

10. REFERENCES

"Note: To Recipients of the Program Package WIMS-D/4 Version NEA 0329/11," NEA Data Bank Informal Notes.

M. J. Roth, J. D. Macdougall, P. B. Kemshell, "The Preparation of Input Data For WIMS," AEEW-R-538, Atomic Energy Establishment, Winfrith, Dorchester, 1967.

M. J. Roth, "The WIMS Multigroup Scheme Status and Difference Between Versions," AEEW-M-845, Atomic Energy Establishment, Winfrith, Dorchester, 1969.

C. J. Taubman, "The WIMS 69-Group Library Tape 166259," AEEW-M-1324, Atomic Energy Establishment, Winfrith, Dorchester, 1975.

M. J. Halsall, "A Summary Of WIMSD4 Input Options," AEEW-M-1327, Atomic Energy Establishment, Winfrith, Dorchester, June 1980.

P. B. Kemshell, M. Hardcastle, "Revised Transport Cross-Sections For The WIMS Library," AEEW-M-1782, Atomic Energy Establishment, Winfrith, Dorchester, July 1980.

M. J. Halsall, "The Use Of WIMSD4 and LWRWIMS, READWT, And FILSIX, To Generate Two-Group Data For Reactor Calculations," AEEW-M-1785, Atomic Energy Establishment, Winfrith, Dorchester, July 1980.

M. J. Halsall, "Additional Edit Facilities Available On A KDF9 Version of WIMS D," AEEW-M-856, Atomic Energy Establishment, Winfrith, Dorchester, August 1980.

J. D. Macdougall, "Programmes Associated With WIMS Library Tapes," AEEW-M-1783, Atomic Energy Establishment, Winfrith, Dorchester, August 1980.

C. J. Taubman, J. H. Lawrence, "WIMSD4 -- Version 100 and Cataloged Procedure," AEEW-M-1832, Atomic Energy Establishment, Winfrith, Dorchester, February 1981.

W. R. Joubert, "Review Report For WIMSD4.1," RTE01-2/2-046, Atomic Energy Corporation Of South Africa, Pretoria, South Africa, June 13, 1988.

S. Slavic, B. Zefran, M. Ravnik, "WIMS-D/4 for PC-AT386 Computer, Version 1.0," IJS-DP-5729, Josef Stefan Institute, Ljubljana, Yugoslavia, February 7, 1990.

Alexandr Novy, "WIMS-D/4 for PC/AT Computer," Version C Informal Notes, September 1990, Prague, Czechoslovakia.

Huynh Dong Phuong, "Adaptation of WIMS-D/4 to Personal Computers," Version D Informal Notes, September 1990, Institute of Atomic Energy Poland.

Jeremy Whitlock, "Modifications for Using Lahey Fortran F77L-EM/32 with Version B," McMaster University, Ontario, Canada (Sept. 1991).

11. CONTENTS OF CODE PACKAGE

Included are the referenced documents and four DS/HD (1.2 MB) 5.25-inch diskettes (A: C00576/ALLMF/00 and D:C00576/IBMPC/00); for versions (B: C00576/PC386/00 and C: C00576/IPCAT/00), 2 DS/HD (1.2 MB) 5.25-inch diskettes are required.

12. DATE OF ABSTRACT

December 1990; revised October 1991.