Investigation of the Cs(Mo,Te)O Solid Solution and Implications on the Joint Oxyde-Gaine System in Fast Neutron Reactors.

The formation of a thin layer, the so-called Joint Oxyde-Gaine (JOG), between the (U,Pu)O fuel pellets and the cladding has been observed in fast neutron reactors, due to the accumulation of volatile fission products. CsMoO is known to be one of the major components of the JOG, but other elements are also present, in particular tellurium and palladium. In this work, an investigation of the structural and thermodynamic properties of CsTeO and CsMoTeO solid solution is reported.