微流控制备UC核燃料微球中的球形度控制研究  

Research on Sphericity Control in Microfluidic Preparation of UC Nuclear Fuel Microspheres

作　　者：郭林 张名飞 赵保旭 常振旗[1] GUO Lin;ZHANG Mingfei;ZHAO Baoxu;CHANG Zhenqi(Department of Engineering and Applied Physics,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学技术大学工程与应用物理系,安徽合肥230026

出　　处：《新技术新工艺》2021年第1期56-61,共6页New Technology & New Process

基　　金：国家自然科学基金资助项目(21978279);安徽省重点研究与开发计划项目(201904a05020048)。

摘　　要：弥散型核燃料是事故容错燃料(ATF)的一种重要组成形式,碳化铀是弥散型核燃料中一种重要的燃料相材料,为了克服不规则形状带来的应力集中问题,通常将燃料相制备成微球且要求球形度良好。而传统的粉末造粒法制备UC核微球容易带来放射性粉尘污染的问题且球形度不佳,因此,基于聚乙烯醇与硼化物的交联反应特性,提出了一种微流体控制技术湿法制备UC核燃料微球的方法,并详细研究了试验体系中的试验参数对UC微球球形度的影响。试验结果表明,凝固浴中硼酸质量分数为1.000%时可以获得球形度最佳的U 3O 8/C凝胶微球,然后通过分步升温的煅烧模式,制备出球形度为1.09、粒径变异系数为3.73%、密度为11.24 g/cm^3的UC微球,实现了具有高球形度及粒径单分散性的UC核燃料微球的制备。Dispersed nuclear fuel was an important form of accident tolerant fuel(ATF),and uranium carbide was an important fuel phase material in dispersive nuclear fuel.In order to overcome the stress concentration problem caused by irregular shapes,the fuel phase was usually prepared into microspheres with good degree of sphericity.The traditional powder granulation method of preparing UC nuclear microspheres usually caused radioactive dust pollution and poor degree of sphericity.Therefore,a method suitable for wet preparation of UC nuclear fuel microspheres by microfluid control technology was proposed based on the cross-linking reaction characteristics of polyvinyl alcohol and boride,and the influence of experimental parameters in the system on the degree of sphericity of UC microspheres was studied in detail.The results showed that the U 3O 8/C gel microspheres with the optimal degree of sphericity was obtained when the mass fraction of boric acid in the coagulation bath was 1.000%.Then the UC microspheres with a degree of sphericity of 1.09,a particle size variation coefficient of 3.73%,and a density of 11.24 g/cm^3 were prepared through a stepwise heating deadburn mode,which achieved preparation of high deadburn and monodispersity of particle size of UC nuclear fuel microspheres.

关 键 词：事故容错燃料 弥散核燃料 UC微球 微流控 聚乙烯醇 球形度 

分 类 号：TL21[核科学技术—核燃料循环与材料]