Measured and calculated fission-product poisoning in neutron-irradiated uranium-233

Journal Article · Mon Dec 01 00:00:00 EST 1975 · Nucl. Sci. Eng., v. 58, no. 4, pp. 387-413

OSTI ID:4140598

Gunst, S B; Connor, J C; Conway, D E

Samples of $sup 233$U and of natural thorium have been irradiated in high neutron-flux facilities, in both soft and hard neutron spectra, and for both short and long exposure times. Included are exposures resulting in depletions of more than 90 percent of the $sup 233$U in the fissile material and burnups of more than 30,000 MWd/MT in the fertile material. Fission-product poison cross sections in two energy groups (thermal and epithermal) exhibit differences between measurement and calculation that are believed to be attributable to a lack of adequate information on important fission products in the literature. Experimental results for transient absorbers in irradiated $sup 233$U give at least 20,000 b for the neutron absorption resonance integral of $sup 149$Pm. This is a factor of 15 higher than that obtained by a 1/v extrapolation of the thermal cross sections. For transient $sup 135$Xe, the measured absorption is 7.5 percent higher than that calculated using ENDF/B-IV data. Information is also provided concerning such matters as fission yields and neutron absorption of neodymium isotopes, the existence of significant transient fission-product poisons other than $sup 135$Xe and $sup 149$Sm, and the shielding of $sup 233$U by $sup 232$Th. Such shielding suggests the need for a change in the energy dependence of the $sup 232$Th thermal-neutron cross section. (auth)

• Research Organization: Westinghouse Electric Corp., West Mifflin, PA
• NSA Number: NSA-33-008807
• OSTI ID: 4140598
• Journal Information: Nucl. Sci. Eng., v. 58, no. 4, pp. 387-413, Other Information: Orig. Receipt Date: 30-JUN-76
• Country of Publication: United States
• Language: English

Related Subjects

N79300* -Reactors-Reactor Fuels
220300* -Nuclear Reactor Technology-Fuel Elements
*FISSION PRODUCTS- REACTIVITY WORTHS
*FUEL PELLETS- PERFORMANCE TESTING
*URANIUM 233- FISSION PRODUCTS
ACCURACY
BURNUP
COMPARATIVE EVALUATIONS
CROSS SECTIONS
IRRADIATION
NUCLEAR FUELS
PHYSICAL RADIATION EFFECTS
POISONING
THORIUM
URANIUM DIOXIDE