Ceramic processing of uranium–plutonium mixed oxide fuels (U1−yPuy)O2 with high plutonium content
Résumé
The ternary thermodynamic U–Pu–O system has been studied for decades for MOX fuel applications but the phase diagram is still not precisely described mostly in the UO 2 –PuO 2 –Pu 2 O 3 sub-system. Furthermore, uranium–plutonium mixed oxides containing high amounts of plutonium are now being considered within the scope of future nuclear reactors. Within this framework, obtaining homogeneous mixed oxides by powder metallurgy is paramount. The studied process is based on UO 2 and PuO 2 co-milling and applied to compounds with high Pu content. The objective of this study is obtaining microstructures free of local heterogeneities in the U–Pu distribution which are not suitable for research studies. Furthermore, in case of prospective irradiation application, local high Pu concentrations lead to “hot spots” in the material influencing the fission..