Gallium interactions with zircaloy cladding

The effects of Ga from weapons-grade plutonium MOX fuel on zircaloy-IV cladding during power reactor operation have been simulated by implantations of 100 keV Ga-69 ions into a polished zircaloy-IV sample while the sample was maintained at a typical cladding temperature of 375{degrees}C. Analyses were based on scanning electron microscopy, Rutherford backscattering of 280 keV He-3 ions, and secondary ion mass spectroscopy. Subgrains at the zircaloy-IV surface formed at a Ga fluence equivalent to total release of approximately 12 ppm by weight of Ga from the fuel. The subgrains may be an intermetallic compound of Zr{sub 2}Ga. Enhanced diffusion of Ga was observed, but Ga concentrations decreased 3 orders of magnitude over a depth of 3000 {angstrom}