Hydrothermal corrosion studies on nitride fuels

Conference · Fri Jul 01 00:00:00 EDT 2016

OSTI ID:22765233

Jaques, B. J.; Watkins, J.; Butt, D. P. ^[1]; Braine, T. ^[1]; Tyburska-Puschel, B. ^[2]; Xu, P.; Lahoda, E. J. ^[3]

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1. Department of Materials Science and Engineering, Boise State University, 1910 University Dr., Boise, ID 83725 (United States)
2. Department of Engineering Physics, University of Wisconsin-Madison 1500 Engineering Dr., Madison, WI 53706 (United States)
3. Westinghouse Electric Company LLC, Pittsburgh, PA 15235 (United States)

Uranium mononitride (UN) has been identified as a candidate nuclear fuel for use in the current US light water reactor (LWR) fleet as well as in next generation nuclear plants (NGNP), largely due to its high uranium density and thermal conductivity. However, its hydrothermal corrosion performance in accident scenarios has not been thoroughly investigated. In this work, UN was synthesized using a hydride-de-hydride-nitride thermal synthesis route prior to sintering into dense compacts (> 90% TD). The compacts were corroded in a water filled autoclave up to 350 Celsius degrees and 125 atm. The kinetics of corrosion were characterized through phase analysis, mass loss, and microstructural analysis. The phases observed after hydrothermal corrosion correspond only to UN, UO{sub 2}, and UN{sub 2}; no U{sub 2}N{sub 3} was observed. Additionally, it appears that nitrogen uptake into the lattice of the solid product is a product of lattice strain and peak broadening, especially of the UN{sub 2} phase. UO{sub 2} appears to nucleate on the surface of the UN-UO{sub 2} monoliths and consumes the UN grain boundaries which suggests that in pure UN, UO{sub 2} formation proceeds from the surface and moves towards the core, but in samples with nominal concentrations of UO{sub 2}, oxidation from hydrolysis occurs throughout the bulk of the monoliths. Furthermore, it was demonstrated here that UN and UN-UO{sub 2} composites perform better than previously reported in the literature.

• Research Organization: American Nuclear Society - ANS, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
• OSTI ID: 22765233
• Resource Relation: Conference: TOP FUEL 2016: LWR fuels fuels with enhanced safety and performance, Boise, ID (United States), 11-15 Sep 2016; Other Information: Country of input: France; 25 refs.; Related Information: In: TOP FUEL 2016 Proceedings| 1670 p.
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
36 MATERIALS SCIENCE
42 ENGINEERING
CONCENTRATION RATIO
CORROSION
GRAIN BOUNDARIES
HYDRIDES
HYDROLYSIS
MASS TRANSFER
NITROGEN
NUCLEAR FUELS
NUCLEAR POWER PLANTS
SINTERING
STRAINS
TEMPERATURE RANGE 0400-1000 K
THERMAL CONDUCTIVITY
URANIUM
URANIUM DIOXIDE
URANIUM NITRIDES
WATER COOLED REACTORS
WATER MODERATED REACTORS