Abstracts and Available Papers Presented at the
2004 International RERTR Meeting

REACTION LAYER BETWEEN U-7WT%Mo AND Al ALLOYS IN CHEMICAL DIFFUSION COUPLES.

Mirandou M., Granovsky M., Ortiz M., Balart S., Aricó S. and Gribaudo L
CNEA Avda. Gral Paz 1499, B1650KNA, San Martin. Argentina

ABSTRACT
 

Several failures in U-Mo dispersion fuel plates like pillowing and large porosities have been reported during irradiation experiments. These failures have been assigned to the formation of a large (U-Mo)/Al interaction product under high operating conditions. The modification of the matrix by alloying Al to change the interaction layer and improve its irradiation behavior, has been proposed. This paper reports diffusion experiments performed between U-7wt%Mo and various Al alloys containing Mg and / or Si. By the use of Optical Microscopy, SEM and X-Ray diffraction, it was found that with a concentration of 5.2wt% or 7.1 wt%Si the interaction layer is constituted mainly by (U,Mo)(Si,Al)3 and no (U,Mo)Al4 is detected. As part of the studies of properties of the U-Mo alloys the time for isothermal transformation start at different temperatures of the  phase is being evaluated for the present U-7wt%Mo alloy. These results are used to plan the future diffusion program that will include diffusion under irradiation at CNEA RA3 reactor.

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