Abstracts and Available Papers Presented at the
1996 International RERTR Meeting

LEU FUEL DEVELOPMENT AT CERCA
Status as of October 1996
U5Si4 : A NEW PHASE IN THE U/Si DIAGRAM

JP. Durand - G. Olagnon - P. Colomb - Y. Lavastre - M. Grasse

CERCA
ZI Les Berauds - 26104 Romans ( France )

and

H. Noel - V. Queneau

CNRS
Laboratoire de chimie du solide et inorganique moleculaire
Campus Beaulieu
Av. du General Leclerc, 35042 Rennes ( France )

ABSTRACT

A fundamental study has been carried out by CERCA and the French CNRS ( National Scientific Research Center ) as a partner in order to get a better understanding of the U₃Si₂ casting process. On the occasion of this study, a new binary phase, U₅Si₄, has been discovered in the USi phase equilibrium diagram. Synthesis conditions of U₅Si₄ have been determined and the impact of such a discovery is evaluated regarding the production process of U₃Si₂ ingots. It can be concluded that keeping the CERCA's casting tools and within the allowed limits of production parameters, the U₃Si₂ ingots are homogenous without any detectable trace of U₅Si₄ even if a long term heat treatment at the hot rolling temperature is carried out. On the production point of view, perfect knowledge of both metallurgical phase synthesis and the casting process guarantee the quality of U₃Si₂ ingots and powder produced by CERCA.

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