Uranium L3 X-ray absorption data were obtained from two
borosilicate glasses, which are considered as models for radioactive
wasteforms, both before and after leaching. Surface sensitivity to uranium
speciation was attained by a novel application of simultaneous fluorescence
and electron-yield detection. Changes in speciation are clearly discernible,
from U(VI) in the bulk to (UO2)2+-uranyl in the
corrosion layer. The uranium concentrations within the corrosion layer also
show variations with leaching times that can be determined from the
data.