1. NAME AND TITLE
OPEX-II: Radiation Shield Optimization Code.
National Aeronautics and Space Administration, Lewis Research Center, Cleveland, Ohio.
3. CODING LANGUAGE AND COMPUTER
FORTRAN IV; IBM 7090/7094.
4. NATURE OF PROBLEM SOLVED
OPEX-II will determine the minimum weight configuration for spherical laminated shields
subject to the constraint of a constant total dose rate at a selected detector point. Once an
optimized base case is obtained, effects of nominal changes in reactor size, power level, and dose
constraint on shield weight may be estimated. Cost optimization may also be performed by
specifying cost per unit volume rather than density for each region.
5. METHOD OF SOLUTION
The code is an extension of CCC-63/OPEX, which it replaces. The method of steepest descent
has been maintained but the code has been completely rewritten to simplify data input, incorporate
spherical geometry, expand the output, alter the dose-thickness relation, and effect other improvements. The dose rate is approximated by a sum of exponentials representing each dose component
obtained from experiments or analytical calculations.
6. RESTRICTIONS OR LIMITATIONS
Number of regions: 25
7. TYPICAL RUNNING TIME
Estimated running time of the packaged sample problem on the IBM-7090: approximately 1
8. COMPUTER HARDWARE REQUIREMENTS
The code was designed for the IBM 7094 and uses standard I-O.
9. COMPUTER SOFTWARE REQUIREMENTS
The code is operable on the IBM 7090/7094 IBSYS Operating System using IBJOB Processor.
G. P. Lahti, "OPEX-II, A Radiation Shield Optimization Code," NASA TM X-1769 (March
11. CONTENTS OF CODE PACKAGE
Included are the referenced documents and one (1.2MB) DOS diskette which contains the
source code and input and output for a sample problem.
12. DATE OF ABSTRACT
May 1969; updated July 1981, February 1985.
KEYWORDS: OPTIMIZATION; SPHERICAL GEOMETRY