Investigation of the Cs2(Mo,Te)O4Solid Solution and Implications on the Joint Oxyde-Gaine System in Fast Neutron Reactors

Journal article (2020)

Authors

E. Epifano RST/Reactor Physics and Nuclear Materials - AS
Andrea Volfi Politecnico di Milano
Maas Abbink Student
L. van Eijck RST/Neutron and Positron Methods in Materials - AS
Gilles Wallez PSL Research University
Dipanjan Banerjee Katholieke Universiteit Leuven
Philippe M. Martin Université de Montpellier
A.L. Smith RST/Reactor Physics and Nuclear Materials - AS
Research Group
RST/Reactor Physics and Nuclear Materials (AS) (TU Delft)
Copyright: © 2020 E. Epifano, Andrea Volfi, Maas Abbink, Hendrik Nieuwland, L. van Eijck, Gilles Wallez, Dipanjan Banerjee, Philippe M. Martin, A.L. Smith
DOI: https://doi.org/10.1021/acs.inorgchem.0c01307
More Info
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Published Date

2020

Language

English

Faculty

Applied Sciences

Department

RST/Radiation, Science and Technology

Research Group

RST/Reactor Physics and Nuclear Materials

Abstract

The formation of a thin layer, the so-called Joint Oxyde-Gaine (JOG), between the (U,Pu)O2 fuel pellets and the cladding has been observed in fast neutron reactors, due to the accumulation of volatile fission products. Cs2MoO4 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 Cs2TeO4 and Cs2Mo1-xTexO4 solid solution is reported. The existence of a complete solubility between Cs2MoO4 and Cs2TeO4 is demonstrated, combining X-ray diffraction (XRD), neutron diffraction (ND), and X-ray absorption spectroscopy (XAS) results. High-temperature XRD measurements were moreover performed on Cs2TeO4, which revealed the existence of a α-β phase transition around 712 K. Thermal expansion coefficients were also obtained from these data. Finally, phase equilibra points in the Cs2MoO4-Cs2TeO4 pseudobinary phase diagram were collected using differential scanning calorimetry and used to develop a thermodynamic model for this system using a regular solution formalism.