Ultra-fast immobilization of simulated TRPO waste into as-prepared Gd2Zr2O7 by flash sintering

Flash sintering can prepare ceramics in extremely short time, which can significantly improve fabrication efficiency and is promising for processing nuclear waste. Herein, simulated TRPO waste (16 components containing low-melting components) was directly added into as-prepared Gd2Zr2O7, and a series of waste forms were successfully prepared by flash sintering at 950 °C for only 3 min. It was demonstrated that samples prepared by flash sintering showed almost no loss of simulated low-melting-point radionuclide, while samples prepared by pressureless sintering have certain losses of simulated low-melting-point radionuclide. The 42 d leaching rates of Mn, Ce, Nd, and Gd of the flash sintered samples were 8.21×10-5, 5.31×10-7, 4.04×10-6, and 1.04×10-6 g·m-2·d-1, respectively, showing excellent chemical durability. This work proves that flash sintering technology can effectively suppress nuclear leaks during immobilization, along with excellent chemical durability.