Thermal conductivity is a key property governing the thermomechanical behaviour of nuclear fuels. It depends, in particular, on their microstructure and porosity, which can reach high levels in MOX fuels (mixed uranium and plutonium oxides) used in fast neutron reactors (FNRs).
This PhD aims to understand and quantify the influence of porosity on the thermal conductivity of MOX fuels, with the objective of establishing a predictive law that accounts for pore fraction, size, shape and interconnectivity. The study will build on recent experimental measurements performed at the European Commission’s Joint Research Centre (JRC) in Karlsruhe, at temperatures of up to 2700K, and on comparisons between these measurements and numerical simulations at the microstructural scale.
The PhD will be carried out at CEA Cadarache, within IRESNE, in the Laboratory for Expertise and Validation of Multi-Reactor-Technology Applications (LEVA). The collaboration with the JRC will provide an international scientific environment. The research will lead to scientific publications and conference presentations. It will also provide the opportunity to develop skills in experimental data analysis and numerical modelling, which are transferable to other areas of materials science and engineering.

Thermal conductivity of mixed oxide fuel (MOX): effect of temperature, elementary chemical composition, microstructure and burn-up in reactor, PhD thesis by Plamen Bonev at CEA, DEC/SESC/LEVA (2023), available through the TEL – Thèses en ligne portal.