Microstructure and thermophysical characterization of mixed oxide fuels

Conference · Thu Jan 01 00:00:00 EST 2009

DOI:https://doi.org/10.1557/PROC-1215-V10-06· OSTI ID:982823

Freibert, Franz J ^[1]; Salich, Tarik A ^[1]; Schwartz, Daniel S ^[1]; Hampel, Fred G ^[1]; Mitchell, Jeremy N ^[1]; Davis, Charles C ^[1]; Neuman, Angelique D ^[1]; Willson, Steve P ^[1]; Dunwoody, John T ^[1]

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1. Los Alamos National Laboratory

Pre-irradiated thermodynamic and microstructural properties of nuclear fuels form the necessary set of data against which to gauge fuel performance and irradiation damage evolution. This paper summarizes recent efforts in mixed-oxide and minor actinide-bearing mixed-oxide ceramic fuels fabrication and characterization at Los Alamos National Laboratory. Ceramic fuels (U{sub 1-x-y-z}u{sub x}Am{sub y}Np{sub z})O{sub 2} fabricated in the compositional ranges of 0.19 {le} x {le} 0.3 Pu, 0 {le} y {le} 0.05 Am, and O {le} z {le} O.03 Np exhibited a uniform crystalline face-centered cubic phase with an average grain size of 14{micro}m; however, electron microprobe analysis revealed segregation of NpO{sub 2} in minor actinide-bearing fuels. Immersion density and porosity analysis demonstrated an average density of 92.4% theoretical for mixed-oxide fuels and an average density of 89.5 % theoretical density for minor actinide-bearing mixed-oxide fuels. Examined fuels exhibited mean thermal expansion value of 12.56 x 10{sup -6} C{sup -1} for temperature range (100 C < T < 1500 C) and ambient temperature Young's modulus and Poisson's ratio of 169 GPa and of 0.327, respectively. Internal dissipation as determined from mechanical resonances of these ceramic fuels has shown promise as a tool to gauge microstructural integrity and to interrogate fundamental properties.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 982823
• Report Number(s): LA-UR-09-08097; LA-UR-09-8097; TRN: US1004305
• Resource Relation: Journal Volume: 1215; Conference: Materials Research Society 2009 Fall Meeting ; November 30, 2009 ; Boston, MA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AMBIENT TEMPERATURE
CERAMICS
ELECTRON MICROPROBE ANALYSIS
FABRICATION
GRAIN SIZE
IRRADIATION
LANL
MICROSTRUCTURE
MIXED OXIDE FUELS
NUCLEAR FUELS
PERFORMANCE
POROSITY
SEGREGATION
THERMAL EXPANSION
THERMODYNAMICS