1. NAME AND TITLE
FORSS: A Sensitivity and Uncertainty Analysis Code System.
Oak Ridge National Laboratory, Oak Ridge, Tennessee.
3. CODING LANGUAGE AND COMPUTER
Fortran IV, Assembler language; IBM 360/370 (A) and CDC (B).
4. NATURE OF PROBLEM SOLVED
FORSS is a code system used to study relationships between nuclear reaction cross sections,
integral experiments, reactor performance parameter predictions, and associated uncertainties. Results
of integral experiments may be incorporated through FORSS to improve uncertainty estimates of
reactor performance for devices being designed. The FORSS development is based upon transport
theory (there is a diffusion theory option) so that the same tool is applicable to both shielding and
reactor core problems in multidimensional geometry.
5. METHOD OF SOLUTION
For a variety of assemblies and performance parameters, the nuclear data sensitivity is tabulated
as a function of nuclide, reaction type, and energy. Nuclear data induced uncertainties are quantified
and results of integral experiments are incorporated in a consistent fashion resulting in improved
uncertainty estimates of reactor performance for devices being designed. A first attempt is made in
the quantitative specification of new cross section measurements required to satisfy specific design
6. RESTRICTIONS OR LIMITATIONS
7. TYPICAL RUNNING TIME
The sample problem required various times to execute each step ranging from 10 seconds to 20
minutes on the IBM 360/91.
8. COMPUTER HARDWARE REQUIREMENTS
FORSS is operable on the IBM 360/370 series (A) or on a CDC computer (B). It uses a maximum
of 23 tapes or direct access devices and requires 170 K to 560 K storage.
9. COMPUTER SOFTWARE REQUIREMENTS
A Fortran H or Assembler compiler is required.
C. R. Weisbin, J. H. Marable, J. L. Lucius, E. M. Oblow, F. R. Mynatt, R. W. Peelle, and F. G. Perey, "Application of FORSS Sensitivity and Uncertainty Methodology to Fast Reactor Benchmark Analysis," ORNL/TM-5563 (December 1976).
J. L. Lucius, C. R. Weisbin, J. H. Marable, J. D. Drischler, R. Q. Wright, and J. E. White, A
"User's Manual for the FORSS Sensitivity and Uncertainty Analysis Code System," ORNL-5316
11. CONTENTS OF CODE PACKAGE
Included are the referenced documents and one (1.2MB) DOS diskette which contains the source
codes and sample problem input and output.
12. DATE OF ABSTRACT
KEYWORDS: SENSITIVITY ANALYSIS; MULTIGROUP; DISCRETE ORDINATES; ADJOINT