原位法制备具有核壳结构的弥散型核燃料粗胚

Preparation of Dispersed Nuclear Fuel Crude Embryo with Core-Shell Structure by in-situ Method

事故容错燃料(ATF)是为提高核燃料在事故尤其是严重事故工况下的安全性能,核能界提出的新一代高安全性核燃料,弥散型核燃料是ATF中的一种重要燃料。以金属基质构成的弥散型燃料有着最优异的性能,但是在事故条件下,金属材料会和水蒸气反应产生氢气,大大降低了核燃料芯块的安全性能。针对这一问题,探讨了一种新的方法,利用不同密度和尺寸的微粒在三维旋转混合器中混合时的偏析现象,实现了核(U3O8-Mo-SiC)壳(SiC)结构弥散型核燃料芯块粗胚的原位制备。详细讨论了材料密度以及混合时间对核壳结构弥散核燃料芯块的壳层形成尺寸影响。这一研究有助于降低以金属为弥散介质的弥散核燃料在事故条件下与水蒸气的反应性,提高核燃料的事故容错性能。

Accident tolerant fuel(ATF)was a new generation of high safety nuclear fuel proposed by the nuclear energy industry to improve the safety performance of nuclear fuel under accident,especially under severe accident conditions.Dispersion nuclear fuel was an important fuel in ATF.Dispersion fuel composed of metal matrix had the best performance,but under accident conditions,metal material will react with water vapor to produce hydrogen,which greatly reduced the safety performance of nuclear fuel pellet.Aimed at this problem,a new method was discussed.The core(U 3O 8-Mo-SiC)-shell(SiC)coarse nuclear fuel pellets with core-shell structure were prepared through in-situ preparation by using the segregation phenomenon of particles of different densities and sizes mixed in a three-dimensional rotating mixer.The influence of material density and mixing time on the size of the shell formation of core-shell dispersed nuclear fuel pellets was discussed in details.This study helped to reduce the reactivity of metal-based dispersive nuclear fuels with water vapor under accident conditions and improved the fault tolerance of nuclear fuels.