Fig. 1 Sol–gel process used to prepare dense (Th,U)O 2 fuel (adapted from Refs. Matthews [ 28 ], Turner [ 29 ], and Onofrei [ 30 ]) More about this image found in Sol–gel process used to prepare dense (Th,U)O 2 fuel (adapted from Refs. M...

Fig. 2 Extruded slugs of (Th,U)O 2 sintered at 1600 °C, density of 9.7 g/cm 3 (from original CNL internal reports, and similar to that reported in Ref. [ 30 ]) More about this image found in Extruded slugs of (Th,U)O 2 sintered at 1600 °C, density of 9.7 g/cm 3 (f...

Fig. 3 Microstructure of extruded (Th,U)O 2 slugs sintered at 1600 °C obtained at two denitration temperatures: ( a ) 475 °C (748 K), (250X magnification), and ( b ) 600 °C (873 K), (400X magnification) (from original CNL internal reports, and similar to that reported in Ref. [ 30 ]) More about this image found in Microstructure of extruded (Th,U)O 2 slugs sintered at 1600 °C obtained at...

Fig. 4 Longitudinal cross sections of ThO 2 pellets (shown in green) imaging Uranium penetration (black/grey color) as a function of impregnation times (min) (from original CNL internal reports, and similar to that reported in Refs. [ 33 ]) More about this image found in Longitudinal cross sections of ThO 2 pellets (shown in green) imaging Uran...

Fig. 5 Examples of granular-like pellet microstructures with ( a )large, open pores and ( b ) low density porous regions between the high density granules (from original CNL internal reports, and similar to that reported in Ref. [ 39 ]) More about this image found in Examples of granular-like pellet microstructures with ( a )large, open pore...

Fig. 6 Typical ThO 2 fuel pellet fabrication process including three possible powder mixing methods (from original CNL internal reports, and similar to that reported in Refs. Dimayuga [ 43 ] and Dimayuga et al. [ 44 ]) More about this image found in Typical ThO 2 fuel pellet fabrication process including three possible pow...

Fig. 7 Alpha autoradiograph of a (Th,Pu)O 2 pellet produced using a low intensity powder blending method (from original CNL internal reports, and similar to that reported in Ref. [ 45 ]). Note: the diameter of the fuel pellet is of the order of 1.2 cm. More about this image found in Alpha autoradiograph of a (Th,Pu)O 2 pellet produced using a low intensity...

Fig. 8 Typical ( a ) porosity and ( b ) microstructure of (Th,U)O 2 fuel pellets produced using a powder co-milling method (from original CNL internal reports, and similar to that reported in Ref. [ 48 ]) More about this image found in Typical ( a ) porosity and ( b ) microstructure of (Th,U)O 2 fuel pellets ...

Fig. 9 SEM images of particle size analysis: ( a ) as-received powder and ( b ) 3-hour milled powder. Semi-log plots of the particle and Gaussian fitted particle size distributions are shown on the right. More about this image found in SEM images of particle size analysis: ( a ) as-received powder and ( b ) 3-...

Fig. 10 Green and sintered pellet density and powder average particle size as a function of milling time (Color version online.) More about this image found in Green and sintered pellet density and powder average particle size as a fun...

Fig. 11 Pellet porosity as a function of milling time More about this image found in Pellet porosity as a function of milling time

Fig. 12 Ceramographic image of an unetched pellet produced with as-received powder More about this image found in Ceramographic image of an unetched pellet produced with as-received powder