1. NAME AND TITLE
ASOP: Multigroup One-Dimensional Discrete Ordinates Transport Code System for Shield
ANISN: The CCC-254A/ANISN-ORNL source file is included in this package.
Oak Ridge National Laboratory, Oak Ridge, Tennessee.
3. CODING LANGUAGE AND COMPUTER
FORTRAN 77; IBM RS/6000 and IBM PC running Linux. (C00126IRISC00).
4. NATURE OF PROBLEM SOLVED
ASOP is a shield optimization calculational system based on the one-dimensional discrete
ordinates transport code system ANISN (CCC-254). It has been used to design optimum shields
for space applications of SNAP zirconium-hydride-uranium-fueled reactors and uranium-oxide
fueled thermionic reactors and to design beam stops for the ORELA facility.
5. METHOD OF SOLUTION
ASOP generates coefficients of linear equations describing the logarithm of the dose and dose-weight derivatives as functions of position from data obtained in an automated sequence of ANISN calculations. With the dose constrained to a design value and all dose-weight derivatives required to be equal, the linear equations may be solved for a new set of shield dimensions. Since changes in the shield dimensions may cause the linear functions to change, the entire procedure is repeated until convergence is obtained.
The detailed calculations of the radiation transport through shield configurations for every step
in the procedure distinguish ASOP from other shield optimization computer code systems which
rely on multiple component sources and attenuation coefficients to describe the transport.
6. RESTRICTIONS OR LIMITATIONS
Problem size is limited only by machine size.
7. TYPICAL RUNNING TIME
The sample case executed in about 1 minute on IBM RS/6000 model 590.
8. COMPUTER HARDWARE REQUIREMENTS
The code runs on the IBM RS/6000 or on IBM compatible personal computers running Linux.
9. COMPUTER SOFTWARE REQUIREMENTS
RSICC tested ASOP on the IBM RS/6000 with xlf 18.104.22.168 compiler under AIX and on a
Pentium running RedHat Linux with g77 (egcs-1.0.3).
a. Included in documentation:
ASOP README (August 20, 1998).
Ward W. Engle, Jr., "A Users Manual for ASOP, ANISN Shield Optimization Program," CTC-INF-941 (September 1969).
b. Background information included in CCC-254/ANISN-ORNL document:
W. W. Engle, Jr., "ANISN, A One-Dimensional Discrete Ordinates Transport Code with Anisotropic Scattering," K-1693 (March 1967).
W. W. Engle, M. A. Boling, and B. W. Colston, "DTF-II, A One-Dimensional, Multigroup
Neutron Transport Program," NAA-SR-10951 (March 1966).
11. CONTENTS OF CODE PACKAGE
Included are the referenced document and one DS/HD (1.44MB) Unix-formatted diskette
which contains a GNU compressed tar file with the source codes, sample problem input and output,
and makefiles for both AIX and Linux.
12. DATE OF ABSTRACT
August 1971; December 1984; July 1988, August 1998.
KEYWORDS: DISCRETE ORDINATES; ONE-DIMENSION; OPTIMIZATION; NEUTRON; GAMMA-RAY; MULTIGROUP