U_(3)O_(8)/ZrN核壳结构微球制备及其在弥散型陶瓷核燃料中的应用研究

Fabrication and Application in Dispersed Ceramic Nuclear Fuel of U_(3)O_(8)/ZrN Core-shell Structure Microspheres

基于光/热引发聚合反应的壳层固化方法在设计构建的同轴双毛细管微流体控制装置中实现高球形度U_(3)O_(8)/ZrN核壳结构微球的制备,调控微流控系统中连续相流量以及核相与壳层相流量比可精准控制U_(3)O_(8)/ZrN核壳结构微球粒径和壳层厚度。提出以U_(3)O_(8)/ZrN核壳结构微球为原料制备高U_(3)O_(8)体积分数的U_(3)O_(8)/ZrN弥散型陶瓷核燃料芯块技术方法。研究结果显示,制备的高达40.8%燃料相体积分数的弥散燃料芯块中U_(3)O_(8)微粒均匀分布在ZrN基质中且没有U_(3)O_(8)微粒堆积粘连。该弥散燃料芯块的热导率比U_(3)O_(8)燃料芯块热导率提高53%,有效改善了陶瓷核燃料的导热性能。

A two co-axial capillary microfluidic device was built up for the preparation of highly spherical U_(3)O_(8)/ZrN microspheres with core-shell structure based on shell solidification by photo/thermal initiation polymerization.Precise control of the particle size and shell thickness of the U_(3)O_(8)/ZrN core-shell structure microspheres is achieved by adjusting the flow rates of the continuous phase and the flow rate ratio of the core phase to the shell phase in the microfluidic control system.A technology method is proposed to prepare U_(3)O_(8)/ZrN dispersed ceramic nuclear fuel pellets with high U_(3)O_(8) volume fraction from U_(3)O_(8)/ZrN core-shell structure microspheres.The results show that the U_(3)O_(8) particles are uniformly distributed in the Zr N matrix without particle agglomeration or adhesion in the prepared dispersed nuclear fuel pellets with a fuel phase volume fraction of up to 40.8%.The thermal conductivity of the dispersed ceramic nuclear fuel pellets is 53% higher than that of U_(3)O_(8) fuel pellets,which effectively improves the thermal conductivity of the ceramic nuclear fuel.