Processing of U-2.5Zr-7.5Nb and U-3Zr-9Nb alloys by sintering process

Conference · Sun Jul 01 04:00:00 EDT 2012

OSTI ID:22105884

Ferraz, W. B.; Lameiras, F. S.; Mazzeu, T. D. O. ^[1]

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1. Centro de Desenvolvimento da Tecnologia Nuclear, CDTN-CNEN, Av. Presidente Antionio Carlos 6.627, 31270-901 Belo Horizonte, MG (Brazil)

To minimize the risk of nuclear proliferation, there is worldwide interest in reducing fuel enrichment of research and test reactors. To achieve this objective while still guaranteeing criticality and cycle length requirements, there is need of developing high density uranium metallic fuels. Alloying elements such as Zr, Nb and Mo are added to uranium to improve fuel performance in reactors. In this context, the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN) is developing the U-2.5Zr-7.5Nb and U-3Zr-9Nb (weight %) alloys by the innovative process of sintering that utilizes raw materials in the form of powders. The powders were pressed at 400 MPa and then sintered under a vacuum of about 1x10{sup -4} Torr at temperatures ranging from 1050 deg. to 1500 deg.C. The densities of the alloys were measured geometrically and by hydrostatic method and the phases identified by X ray diffraction (XRD). The microstructures of the pellets were observed by scanning electron microscopy (SEM) and the alloying elements were analyzed by energy dispersive X-ray spectroscopy (EDS). The results obtained showed the fuel density to slightly increase with the sintering temperature. The highest density achieved was approximately 80% of theoretical density. It was observed in the pellets a superficial oxide layer formed during the sintering process. (authors)

• Research Organization: American Nuclear Society, Inc., 555 N. Kensington Avenue, La Grange Park, Illinois 60526 (United States)
• OSTI ID: 22105884
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
22 GENERAL STUDIES OF NUCLEAR REACTORS
36 MATERIALS SCIENCE
CRITICALITY
DENSITY
ENRICHMENT
FUEL CYCLE
NIOBIUM ALLOYS
NUCLEAR FUELS
OXIDES
PELLETIZING
POWDERS
PRESSURE RANGE MEGA PA 100-1000
RAW MATERIALS
SCANNING ELECTRON MICROSCOPY
SINTERING
TEST REACTORS
URANIUM
URANIUM ALLOYS
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY
ZIRCONIUM
ZIRCONIUM COMPOUNDS