Construction and Calibration of a Fast Neutron Spectrum Generator PDF Download

Author: Kenneth Dwight Dobbin
Publisher:
ISBN:
Category : Neutron sources
Languages : en
Pages : 228

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Book Description
A standard fast reactor spectrum can be created by the partial moderation of the U-235 fission spectrum in an air cavity. Spherical natural uranium shells are driven by thermal neutrons from a thermal column. The uranium is placed at the center of a spherical graphite hohlraum to reduce the anisotropic effect of a planar source of thermal neutrons. The Oregon State University (OSU) fast neutron spectrum facility design employs this method which is being used by Albert Fabry in Mol, Belgium and the NISUS assembly in London, United Kingdom, to create a fast neutron spectrum. The OSU facility uses the ther malizing column of a TRIGA Mark II reactor for a thermal neutron source. The mechanical design is presented showing the location of the facility, the aluminum container and internals, and the transport assembly. Two computer codes are introduced in the nuclear design. SLAB is a first approximation diffusion theory code which justifies the use of one foot of graphite backed with water in place of "infinite graphite." FASTSPEC is a diffusion theory approximation code in spherical geometry which shows that the design will produce a spectrum characteristic of a fast reactor. Phase I operation is a mechanical test, health physics evaluation, and a thermal neutron calibration of the facility with a thermal neutron absorber in place of the uranium. The data for phase I is included. Phase II operation will be the insertion of an uranium driver shell and the calibration of the fast spectrum. Only phase I is complete at this time.