With current trends to increase fuel burn-up in light-water nuclear reactors, minimising fuel
cladding tube degradation mechanisms such as corrosion becomes more important. The
corrosion of Zr alloys, which make up the cladding, is an electrochemically-driven process
between the metal and the oxygen-containing environment, and has been found to be highly
dependent on the microstructure and texture of the oxide layer that forms. In this thesis,
we used a combination of density functional theory (DFT) and new crystallographic texture
analysis applied to experimental crystal orientation data obtained using electron backscatter
diraction (EBSD) and scanning precession electron diraction in the transmission electron
microscope (SPED), to distinguish between the eects of lattice matching between the
metal and the oxide crystals and the transformational compressive stress as mechanisms
for both the tetragonal and the monoclinic oxide texture formation. Furthermore, we used
DFT to examine how the structural and electronic properties of a low energy monoclinic
grain boundary, present in high fraction in experimental texture maps, are aected by the
presence of selected point defects that are important for the corrosion process.