Abstract: Nuclear fuel production wastewater generated from uranium purification and conversion contains refractory extractants such as TBP and TOA, as well as natural radionuclides. Traditional ozone catalytic oxidation processes suffer from low ozone utilization (usually below 30%) and poor mass transfer efficiency, mainly due to large bubble size (1-5 mm) and short residence time (<30 s). Microbubble technology provides a feasible solution to enhance gas-liquid mass transfer, but conventional microbubble generators cannot meet the strict requirements of nuclear industry environments, including radiation resistance, high salinity, and wide temperature variation. This work aims to develop a nuclear-grade microbubble generation system using self-made SiC microporous membrane and to reveal the regulation mechanism of inlet temperature on microbubble generation characteristics. A self-developed SiC ceramic microporous membrane was prepared via high-temperature solid-state sintering. The membrane had a SiC content of 99.4%, porosity of 52.6%, filtration accuracy of 1.02 μm, and a trumpet-shaped pore structure from inside to outside. A prototype microbubble generator integrating the SiC membrane was assembled with 316L stainless steel and radiation-resistant sealing materials. Experiments were carried out in an ethylene glycol-water solution (1∶9 by volume) to simulate nuclear wastewater. Nitrogen was used as the gas source instead of ozone for safety. Two operating conditions were designed: constant temperature inlet (19-21 ℃) and variable temperature inlet (−14 ℃ rising to 19-21 ℃). Four gas flow rates (5, 15, 30, 45 L/min) were tested. Key parameters including Sauter mean size (D32), bubble concentration, size distribution uniformity, and light transmittance were measured by PBM online monitoring system, Malvern Mastersizer 2000 particle size analyzer, and high-speed camera (1 000 fps). Results show that inlet temperature and gas flow rate jointly dominate microbubble generation. Under variable temperature conditions, D32 decreases more significantly with increasing gas flow rate than under constant temperature. At 45 L/min, D32 reaches 135.72 μm, which is 18.8% lower than that under constant temperature. The volume fraction of microbubbles in the high-efficiency mass transfer range (80-200 μm) reaches 72.52%. The total bubble concentration is 28 562 per mL, increased by 24.1% compared with constant temperature. A new mechanism of low-temperature gas intake→heating expansion→enhanced crushing kinetic energy is proposed. The superposition of temperature variation advantages and high shear force at high gas flow rate promotes bubble breakup and narrows size distribution. The span of size distribution is below 0.4 under all conditions, indicating excellent uniformity. The SiC microporous membrane exhibits outstanding radiation resistance (≥1×10⁸ Gy for γ-rays) and corrosion resistance. The energy consumption of the prototype is controlled within 0.4 kW·h/m³, meeting the nuclear industry standard (≤0.5 kW·h/m³). This technology effectively improves ozone utilization and mass transfer efficiency without replacing membrane modules or adding chemicals, showing good adaptability to extreme nuclear industrial conditions. This study provides theoretical support and technical reference for the application of microbubble technology in radioactive wastewater treatment.