Reactive spark plasma synthesis of CaZrTi2O7 zirconolite ceramics for plutonium disposition

Near single phase zirconolite ceramics, prototypically CaZrTi 2 O 7 , were fabricated by reactive spark plasma sintering (RSPS), from commercially available CaTiO 3 , ZrO 2 and TiO 2 reagents, after processing at 1200 °C for only 1 h. Ceramics were of theoretical density and formed with a controlled mean grain size of 1.9 ± 0.6 μm. The reducing conditions of RSPS afforded the presence of paramagnetic Ti 3+ , as demonstrated by EPR spectroscopy. Overall, this study demonstrates the potential for RSPS to be a disruptive technology for disposition of surplus separated plutonium stockpiles in ceramic wasteforms, given its inherent advantage of near net shape products and rapid throughput.