Assessing ceramic powder quality by activated Sinterability Test: The case of UO2

•Large ceramic powder blends are usually accepted for processing on the basis of a sinterability test on a representative sample from the blend. The test is carried out under pressing and sintering conditions similar to those applied in regular manufacturing.•On the basis of experiments, the author suggests activated sintering at normal sintering temperature in place of conventional sintering. The activation is achieved by admixed additives or by modifying sintering atmosphere.•Defects that are not revealed in conventional sinterability test are revealed in activated sintering test. Packing defects (if present in the green body) are further magnified in activated sinterability test. The temperature at which open porosity / permeability are lost is shifted downwards in activated sintering. Additive activated or atmosphere activated sinterability test is expected to bring out quality differences in powder blends that behave the same way in conventional sinterability test.•A descriptive desintering model of agglomerated powders is based on specific surface area, additives and sintering atmosphere.•Powder blends that passed the high temperature activated sintering test may be processed through low temperature sintering technique without risk of in-reactor fuel densification. Ceramics fail by brittle fracture due to flaws and affect process yield. The starting material is usually in powder form. UO2 pellets are obtained by pressing powder, sintering and finish grinding. Large powder blends are usually accepted for pressing and sintering after evaluating a small representative powder sample by conducting a sinterability test under regular process conditions. On the other hand, this paper recommends activated sintering conditions, such as those achieved with additives or sintering atmosphere control. Many defects in ceramics have origins in the powder. For example, large hard agglomerates in the powder can cause packing difficulties in pressing. Defects that are not detected in normal sintering may be noticed more readily in activated sintering due to defect amplification. In sintering, open porosity ceases after reaching a density of ∼93 % TD. The residual closed porosity tends to shrink on further sintering. The temperature at which open porosity or permeability is lost shifts to a lower temperature in activated sintering. Yet, activated sintering is to be carried out at conventional high sintering temperature, to be able to amplify and expose pellet defects du