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

Technical Report · Thu Mar 15 04:00:00 EST 1962

OSTI ID:4813102

Johns, G L

FICS, which is a group constant program available as an alternative to the WOXK routine within the KARE System is described. 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. 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 and a high-absorption spectrum, covering the energies below 0.625 ev in 32 lethargy irtervals. Thermal group constants are determined by averaging lethargy-dependent microscopic cross sections and diffusion constants over the composite spectrum. FICS' thermal constarts are temperature-dependent with region temperatures from 68 to 600 deg 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 ten optional calculations which can modify the group constants for special purposes. Included are: automatic Xenon determination; special prescriptions for thin, highly absorbing regions; an adjoint option; a technique for handling window shade control rods; and automatic calculation of fission products. (auth)

• Research Organization: Knolls Atomic Power Lab., Schenectady, N.Y.
• DOE Contract Number: W-31-109-ENG-52
• NSA Number: NSA-16-026196
• OSTI ID: 4813102
• Report Number(s): KAPL-M-RPC-3
• Country of Publication: United States
• Language: English

Related Subjects

ABSORPTION
CONTROL ELEMENTS
CROSS SECTIONS
DIFFUSION
DIGITAL SYSTEMS
ENERGY RANGE
FISSION
GROUP THEORY
KARE-CODE
NEUTRINOS
NEUTRON FLUX
NEUTRONS
NUMERICALS
PHYSICS
PROGRAMMING
SLOWDOWN
SPECTRA
TEMPERATURE
THERMAL NEUTRONS
XENON