b'Figure 2. TEM characterization results of fuel-Cr diffusion barrier interacting interface. A STEM HAADF (a) and a high magnification BF (b) image showing the overall microstructure near the fuel-Cr diffusion barrier interacting interface. Red arrows in (a) highlight the interacted Cr grain boundaries. For the blue box highlighted region in (a), the STEM BF and HAADF and BF images is displayed in (b) and (c), respectively, the elemental mapping of Cr, Zr, U, Nd, and Ce is in (d), (e), (f), (g), and (h), respectively. (i) A TEM image of the nano crystalline Cr/Zr grains for collecting TEM selected area diffraction patterns as shown in (j) and (k)166 2023|AFC ACCOMPLISHMENTS'