摘要
UN燃料具有铀密度高、熔点高、热导率高、热膨胀系数低、辐照稳定性好等优点，是未来空间核电源、核火箭、快堆和ADS的重要候选燃料。本文采用金属铀粉与氮气在300～400℃直接发生化合反应，制得单相U2 N3粉末。粒度为38.3μm的 U2 N3粉末在1600℃真空热压烧结，制得相对密度为93.5％、存在少量金属铀相的U N陶瓷；而18.1μm的U2 N3粉末在1550℃真空热压烧结，制得相对密度为96.1％、不残留金属铀相的 U N陶瓷，U与N的总质量分数为99.57％，每个金属杂质含量均低于50μg/g ，氧含量为1048μg/g ，碳含量为502μg/g。U2 N3在1027℃以上将会完全分解成UN ，UN在1627℃以上也会发生分解。
Uranium nitride nuclear fuel has lots of advantages ,such as high uranium density ,high melt point ,high thermal conductivity ,low thermal expansion coefficient and high irradiation stability ,so it is an important candidate fuel for the future nuclear energy systems including space nuclear reactor ,nuclear rocket ,fast reactor and ADS . In this research ,U2N3 powders were fabricated by nitriding reaction of nitrogen and uranium powders .UN ceramic pellets with density of 93.5% TD （theory density） have a little residual metal uranium when U2 N3 powders with median particle size of 38.3 μm were hot press sintered in vacuum at 1 600 ℃ .But UN ceramic pellets can be vacuum hot press sintered to 96 .1% TD at 1 550 ℃ by 18.1 μm U2 N3 powders ,without residual uranium ,in w hich the total mass content of U and N is 99.57% ,the impurity content of each heavy metal is less than 50 μg/g ,the oxygen content is 1 048 μg/g ,and the car-bon content is 502 μg/g .U2 N3 will completely be decomposed into UN above 1 027 ℃ , and UN will also be decomposed above 1 627 ℃ .
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2014年第10期1850-1856,共7页
Atomic Energy Science and Technology
关键词
UN
U2N3
金属铀
氮化反应
热压烧结
UN
U2 N3
metal uranium
nitriding reaction
hot press sintering
