FICS--A PROGRAM TO COMPUTE FEW-GROUP CONSTANTS WITHIN THE KARE DIFFUSION THEORY SYSTEM

Technical Report · Tue Jan 01 04:00:00 EST 1963

OSTI ID:4729918

Goodman, D E

FICS is a group constant program available as an alternative to the WOXX routine within the KARE System. FICS computes diffusion constants and macroscopic cross sections for slowing down, absorption, nu -fission, and total removal in two, three, or four energy groups for each compositional region in the reactor model. The one-group thermal constants are provided by a variational technique which computes an approximate Wigner-Wilkins flux spectrum as a linear combination of two trial spectra. These consist of a low-absorption spectrum and a high-absorption spectrum, covering the energies below 0.625 ev in 32 lethargy intervals. The thermal group constants are determined by averaging lethargy- dependent microscopic cross sections and diffusion constants over the composite spectrum. FICS' thermal constants are temperaturedependent with region temperatures from 68 to 600 nif- F permitted. In the fast energy range, 10 Mev to 0.625 ev, the program computes temperature-independent constants in one, two, or three energy groups. These are determined from stored microscopic cross sections which were obtained by curve fitting to MUFT parameters over a wide range of metal-water ratios. FICS provides optional calculations, some of which modify the group constants for special purposes, while others merely prepare and transmit data to other segments. Included are: automatic Xenon determination; special prescriptions for thin, highly absorbing regions; an adjoint option; a technique for handling window shade'' control rods; automatic calculation of fission products; mixed number density modification; spectrum option; precalculated group constant option, depletion option; AMOK option; and special calculations for r-z synthesis. (auth)

• Research Organization: Knolls Atomic Power Lab., Schenectady, N.Y.
• DOE Contract Number: W-31-109-ENG-52
• NSA Number: NSA-17-019197
• OSTI ID: 4729918
• Report Number(s): KAPL-M-RPC-3(Rev. 1)
• Country of Publication: United States
• Language: English

Related Subjects

ABSORPTION
COMPUTERS
CONTROL ELEMENTS
CROSS SECTIONS
DENSITY
DIFFUSION
ENRICHMENT
FAST NEUTRONS
FISSION
FISSION PRODUCTS
GROUP THEORY
HYDROGEN
KARE-CODE
METALS
MUFT-CODE
NEUTRON FLUX
NEUTRONS
NUMERICALS
PHYSICS
PROGRAMMING
QUANTITATIVE ANALYSIS
REACTORS
RODS
SLOWDOWN
SPECTRA
TEMPERATURE
THERMAL NEUTRONS
WATER
WIGNER-WILKINS MODEL
XENON