This work is proposed in the frame of studies on the physico-chemical behaviour of the (U,Pu)O2 fuel during irradiation considered for the future reactors of 4th generation. Indeed, this kind of fuel is subject in particular to two specific specific phenomena that can have an impact on its behaviour:
- the formation of a JOG (Joint Oxyde-Gaine), a fission products layer localised between the external surface of the fuel pellet and the inner surface of the cladding material ;
- the FCCI (Fuel-Cladding Chemical Interaction), which leads to the formation of a corrosion layer on the internal surface of the clad containing fission products and elements constituting the cladding material.
The goal is this work is to improve the modelling of the JOG and of the FCCI into the fuel performance code (FPC) GERMINAL, dedicated dedicated to the calculation of the thermo-mechanical and physico-chemical behaviour of fast reactor fuel irradiated in normal and off-normal conditions. For that purpose, the candidate will work on the dedicated calculation scheme of GERMINAL which uses the thermochemical software OpenCalphad and on the comparison of the JOG and of the internal cladding corrosion widths obtained to experimental observations obtained for some irradiation experiments. Complementary stand-alone thermodynamic calculations will be performed with the TAFID, thermodynamic database on nuclear materials developed in an international framework, in order to analyse the thermochemistry JOG/FCCI versus parameters of interest.
This work will be performed in collaboration with a team specialised in thermodynamic modelling, in charge of the TAFID project. The student will thus have the opportunity to exchange on his results in a collaborative frame with international partners. In addition, he will be able to highlight his work through publications and presentations at conferences.