Title page for ETD etd-11142012-040203

Type of Document Master's Thesis
Author Seth, Ernest L.
URN etd-11142012-040203
Title FASPEC, a program to determine group constants for up to 47 groups in a fast neutron spectrum
Degree Master of Science
Department Nuclear Science and Engineering
Advisory Committee
Advisor Name Title
Parkinson, Thomas F. Committee Chair
Edlund, M. C. Committee Member
Thomas, James R. Jr. Committee Member
  • Nuclear reactors
Date of Defense 1985-08-05
Availability restricted

In reactor core design, a gap exists between the manual calculation of few-group constants and the many-group calculation, by large computer programs. A method is needed by which group constants may be calculated easily and quickly. The FASPEC program is designed to reduce the amount of manual calculation and to complement the large program by reducing the number of times the large program must be run to achieve desired results.

The program calculates group constants from 940 microgroups, collapsing to any user-specified number of macrogroups up to 47. FASPEC is based on group-averaged flux calculations by a solution of the Infinite medium neutron transport equation. Flux contributions from inelastic scatter are included while those from neutron up—scatter are not. The energy spectrum considered is from 10 MeV to 0.625 eV. Required input is the atomic number density of each isotope, the number of macrogroups desired and the upper and lower microgroup numbers of each macrogroup. Input is facilitated by prompting in each case. Cross section look-up tables were provided by the Very Improved Monte Carlo code (VIM) for a mid—range Infinite hexagonal lattice. Self-shielding effects are included indirectly. A brief user's guide is provided.

Group constants calculated and stored for either terminal display or printed output are group number, lowest energy of the group,macroscopic removal cross section, macroscopic absorption cross section, diffusion coefficient, flux, macroscopic fission cross section, v, the average number of neutrons emitted per fission, and vΣf.

  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
[VT] LD5655.V855_1985.S474.pdf 3.58 Mb 00:16:34 00:08:31 00:07:27 00:03:43 00:00:19
[BTD] next to an author's name indicates that all files or directories associated with their ETD are accessible from the Virginia Tech campus network only.

Browse All Available ETDs by ( Author | Department )

dla home
etds imagebase journals news ereserve special collections
virgnia tech home contact dla university libraries

If you have questions or technical problems, please Contact DLA.