Remarks on the sintering behavior of UO2–Gd2O3 fuel

The previous work by our group showed experimental evidence that supports the idea that a diffusion barrier is formed around Gd2O3 agglomerates due to the formation of gadolinium-rich (U,Gd)O2 phases with low diffusivity. This would be the reason for the bad sintering behavior of the UO2–Gd2O3 fuel. The objective of this investigation was to confirm that hypothesis by direct experimental evidence. Analysis of the results showed that the diffusion barrier hypothesis is not applicable.