Electron Probe Micro-Analysis of Irradiated Triso-Coated UO sub 2 Particles, (1)

摘要

The Triso-coated low-enriched UO sub 2 particles were subjected to the post-irradiation electron probe micro-analysis. Observations and analyses on the amoeba effect, inclusions and solutes in the UO sub 2 matrix were made. In the cooler side of the particle which suffered extensive kernel migration, two significant features were observed: (1) the wake of minute particles, presumably UO sub 2 , left by the moving kernel in the carbon phase and (2) carbon precipitation in the pores and along the grain boundaries of the UO sub 2 kernel. Both features could be hardly explained by the gas-phase mechanism of carbon transport and rather suggest the solid state mechanism. Two-types of 4d-transition metal inclusions were observed: the one which was predominantly Mo with a fraction of Tc and another which was enriched with Ru and containing significant amount of Si. The Mo and Si were also found in the UO sub 2 matrix; the observation led to the discussion of the oxygen potential in the irradiated Triso-coated UO sub 2 particle. (Atomindex citation 16:018320)