The surface area data of feed oxide powders is of fundamental interest to optimize the process of nuclear fuel fabrication. The single-point Brunauer–Emmet–Teller (BET) specific surface area of several recycled powders (synthesized from rejected scrap fuel pellets) was determined and compared with as-received and standard specified powders. Recycled UO₂, ThO₂, (U,Pu)O₂ powders from bulk microwave dissolution-denitration process showed acceptable specific surface area for fuel pellet fabrication. The dry oxidation–reduction process recycled UO₂ and (U,Pu)O₂ powders demonstrated lower surface area than the standard specified due to larger particle size (D50). The surface area of ThO₂ from bulk microwave dissolutiondenitration (3.5–4.5 m²/g) was comparable to the standard and further enhanced in polyvinyl alcohol (PVA) aided denitration.