Particle size analysis in powders recycled from rejected sintered UO₂ pellets

The particle size distribution of feed UO₂ powder is essential for optimization of fuel fabrication process. Particularly, for the powders those are obtained by recycling of the rejected UO₂ fuel pellets by adapting various processes. In the present work, particle size analysis in several recycled Deeply Depleted UO₂ powders was performed using a laser diffraction particle sizer BETTERSIZE-2600 (test range 0.02-2600µm) under Fraunhofer optical model. The analysis was performed in the wet dispersion mode wherein the samples of UO₂ powder (0.3g each) were dispersed in distilled water at the stirring speed 1600 rpm and continuous ultrasonification (38 kHz). The accuracy check was performed by analysing NIST-traceable polydisperse glass microspheres standard Whitehouse Scientific PS227 (30-350µm) and CaCO₃ working reference powder (WRP) with known optical properties and recommended D90/D10 ratio of ≥1.5. The equivalent spherical diameters are reported as D10, D50 (median diameter) and D90, representing 10%, 50% and 90% of the particles respectively are smaller than the DXX on volume cumulative distribution