Transmission Electron Microscopy Characterization of Irradiated U-7Mo/Al-2Si Dispersion Fuel

Journal Article · Fri Jan 01 00:00:00 EST 2010 · Journal of Nuclear Materials

DOI:https://doi.org/10.1016/j.jnucmat.2009.11.015· OSTI ID:986929

Gan, J; Keiser, Jr, D D; Wachs, D M; Robinson, A B; Miller, B D; Allen, T R

The plate-type dispersion fuels, with the atomized U(Mo) fuel particles dispersed in the Al or Al alloy matrix, are being developed for use in research and test reactors worldwide. It is found that the irradiation performance of a plate-type dispersion fuel depends on the radiation stability of the various phases in a fuel plate. Transmission electron microscopy was performed on a sample (peak fuel mid-plane temperature approximately 109 degrees C and fission density approximately 4.5 x 10 27 fm-3) taken from an irradiated U–7Mo dispersion fuel plate with Al–2Si alloy matrix to investigate the role of Si addition in the matrix on the radiation stability of the phase(s) in the U–7Mo fuel/matrix interaction layer. A similar interaction layer that forms in irradiated U–7Mo dispersion fuels with pure Al matrix has been found to exhibit poor irradiation stability, likely as a result of poor fission gas retention. The interaction layer for both U–7Mo/Al–2Si and U–7Mo/Al fuels is observed to be amorphous. However, unlike the latter, the amorphous layer for the former was found to effectively retain fission gases in areas with high Si concentration. When the Si concentration becomes relatively low, the fission gas bubbles agglomerate into fewer large pores. Within the U–7Mo fuel particles, a bubble superlattice ordered as fcc structure and oriented parallel to the bcc metal lattice was observed where the average bubble size and the superlattice constant are approximately 3.5 nm and approximately 7.5 nm, respectively. The estimated fission gas inventory in the bubble superlattice correlates well with the fission density in the fuel.

• Research Organization: Idaho National Lab. (INL), Idaho Falls, ID (United States)
• Sponsoring Organization: DOE - NE
• DOE Contract Number: DE-AC07-05ID14517
• OSTI ID: 986929
• Report Number(s): INL/JOU-09-16223; TRN: US1006543
• Journal Information: Journal of Nuclear Materials, Vol. 396, Issue 2 - 3; ISSN 0022-3115
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
ALLOYS
ALUMINIUM
ALUMINIUM ALLOYS
BUBBLES
DISPERSION NUCLEAR FUELS
FISSION
FUEL PARTICLES
FUEL PLATES
GASES
IRRADIATION
PERFORMANCE
POST-IRRADIATION EXAMINATION
RADIATIONS
RESEARCH AND TEST REACTORS
RETENTION
SILICON ADDITIONS
STABILITY
SUPERLATTICES
TRANSMISSION ELECTRON MICROSCOPY
dispersion fuel
fission gas bubbles
irradiation performance
RERTR-6 experiment
U-7Mo/matrix interaction layers