Composition and structure of fission product precipitates in irradiated oxide fuels: Correlation with phase studies in the Mo-Ru-Rh-Pd and BaO-UO2-ZrO2-MoO2 Systems

Chemical States of Fission Products and Actinides in Irradiated Oxide Fuels Analyzed by Thermodynamic Calculation and Post-Irradiation Examination

“…The gas phase consists of single elements and oxides as an ideal gas. The matrix phase (MO 2 ) consists of UO 2 Summary of the present calculation is shown in Table 1. It was found that the MO 2 phase that corresponds to the fuel matrix phase and Mo-Me alloy were always stable under the whole conditions.…”

“…temperature and oxygen potential. 1,2) The compounds composed of FPs and actinides would affect significantly the fuel characteristics. Therefore, the behavior of FPs and actinides under irradiation and the properties of their compounds are very important for evaluation of the fuel performance.…”

An Initial Assessment of Potential Production Technologies for Epsilon-Metal Waste Forms

“…In the UNF, elements with low solubility in the UO 2 matrix move from the matrix to grain boundaries, pellet-pellet gaps, and fuel-cladding gaps. Of particular interest in this document are the six metals Mo, Pd, Rh, Ru, Te, and Tc that form the "five metal phase" (Cui et al 2004;Kleykamp et al 1985;Kleykamp and Pejsa 1984). Tellurium was found by Cui et al (2004), but not by Kleykamp and coworkers.…”

“…Further, the compositions of the incoming waste stream also vary over the course of multi-year operation of the plant, as the composition of the ε-metal is known to change with fuel burnup (Kleykamp et al 1985). Recycle of the soluble fractions of the noble metal and Tc also complicates the prediction of the composition of the end product.…”

“…After the dissolution of nuclear fuel, there remains in the dissolver a material called undissolved solids (UDS (Kleykamp et al 1985). Some other undissolved material is likely to be present as well, such as molybdenum-zirconium oxides.…”