场辅助烧结二氧化铀基燃料芯块研究进展

Overview of Field-assisted Sintering Technology in Uranium Dioxide Fuel Pellets

二氧化铀是目前使用最广泛的核燃料,但传统的二氧化铀核燃料热导率低,存在严重的事故隐患。福岛核事故以后,人们提出了事故容错燃料的概念。考虑到二氧化铀基核燃料大规模使用的现状,研究者们开始关注对现有的二氧化铀体系芯块的改进,通过增大晶粒尺寸或引入第二相来提高芯块的导热性。然而,利用传统烧结方法制备掺杂的二氧化铀基复合芯块还存在很多问题和不足。近几年,随着场辅助烧结技术的发展,一些学者开始尝试利用微波烧结、放电等离子烧结、闪烧等场辅助烧结技术制备二氧化铀基复合芯块,并在二氧化铀-碳化硅等类型的复合芯块上取得了一些实质性的进展。

Uranium dioxide is the most widely used nuclear fuel at present,but the low thermal conductivity of traditional fuel could result in possible serious accident.The concept of accident tolerant fuel(ATF)was proposed after the Fukushima nuclear accident.Due to the large-scale utilization of uranium dioxide-based nuclear fuels,it is urgent to increase thermal conductivity of the currently used pellets,by increasing the grain size or introducing second phases.However,there are still various problems and shortcomings when using the conventional methods to prepare doped uranium dioxide pellets.With the development of field-assisted sintering technology in the last years,it has been widely employed to prepare uranium dioxide-based composite pellets.Meanwhile,significant progress has been made in various composite fuel pellets,such as UC2-SiC.The paper offers an overview of the progress in this research topic.