全陶瓷包覆核燃料是事故容错核燃料中最具应用前景的核燃料类型。本项目基于微流体控制技术、界面反应技术以及共沉淀混合技术设计提出湿法无粉制备高铀含量的全陶瓷UO2-ZrN包覆核燃料技术路线并开展高性能包覆燃料芯块的制备研究。研究包括：①设计构造微流体混合/微流体控制液滴制备一体化系统，突破内凝胶法制备铀酰凝胶微球的低温环境限制，实现常温铀酰凝胶微球的制备及机理研究。②利用静电引力原理设计制备高界面相容性的微米级UO2-ZrN包覆燃料微球，包覆微球的核相尺寸和包覆层厚度均实现精准可控制备。③提出包覆燃料颗粒/弥散介质共沉淀混合概念，研究获得高铀含量的全陶瓷包覆燃料芯块的制备技术。探索包覆颗粒燃料芯块的微观结构变化与控制规律，并提出控制微观结构变化的机理。④应用有限元分析方法结合实验数据详细研究项目研制的燃料芯块热学性能。

Fully ceramic microencapsulated fuel (FCM) is the most promising nuclear fuel type in accident-tolerant fuel (ATF). Based on microfluidic technology and interface reaction technology as well as co precipitation-mixing technique, a wet and dust-free preparation route of UO2-ZrN nuclear fuel of FCM fuels are designed, and the fabrication of high-performance FCM fuel pellets of UO2-ZrN will be studied. The detailed researches are as follows: ①an integrated micromixer/microfluidic system used for preparing uranyl gel beads controllably at room temperature by ICP technique that a near zero-centigrade environment is conventionally needed for avoiding the precipitation of the sol solution will be designed and built, and the preparation mechanism of uranyl gel beads will be studied in detail. ②The high interfacial compatibility of micron sized UO2 microsphere encapsulated with ZrN fuel beads will be synthesized by introducing electrostatic attraction principle in fabrication processes and the diameter of UO2 and the encapsulating thickness of as-prepared encapsulated fuel beads will be controlled precisely thanks to microfluidic. ③The concept of co precipitation mixing for encapsulated fuel particles/inert matrix is proposed, and the preparation of full ceramic microencapsulated fuel with high uranium content is studied.④The thermal performance of fuel pellets developed by the project will be studied in detail by using the finite element analysis method and experimental data.