摘要
Gd2O3-UO2可燃毒物燃料是近年来核电站采用较为普遍的可燃毒物之一.本文研究了在Gd2O3-UO2芯块中添加Al2O3、TiO2、V2O5各150μg/g的复合助烧剂对芯块微观结构的影响.研究表明添加复合助烧剂后可以降低Gd2O3-UO2芯块的致密化温度,在H2气氛中,1500℃烧结4h后的Gd2O3-UO2芯块的密度可达～97%TD.芯块的闭口L在1400～1750℃整个温度范围内一直呈下降趋势,烧结温度为1750℃时芯块中气孔数量比1600℃时减少,但单个气孔体积增大,其主要机制可能是小气孔之间发生融合.添加助烧剂后,在1400～1600℃温度之间晶粒生长速度出现不一致,部分晶粒开始迅速生长,晶粒大小分布出现双峰现象;当温度为1750℃时,晶粒大小分布为正态分布,双峰现象消失,平均晶粒尺寸约为25 μm.
Gd2O3-UO2 is widely used as burnable absorber in nuclear power plants in recent years. It was investigated that multiple sintering additives which included respectively 150 μg/g Al2O3, TiO2, V2O5 had effects on the microstructure of Gd2O3-UO2 pellets in the report. It is shown that multiple sintering additives decreases the sintering temperature of Gd2O3-UO2 pellets, and the pellet density reaches -97% TD after sintering in hydrogen atmosphere at 1500°C for 4 hours. The close pores of pellets always reduce during 1400-1750°C, and the total number of close pores of the pellets sintered at 1750°C is less than that at 1650°C. However, the volume of single pore increases, and the main mechanism may be the small pores amalgamation. The grain growth rate becomes differences between different grains during 1400°C-1600°C. Some grain develops rapidly and there are double peaks in the distribution of grain size. The double peaks are disappeared when the sintering temperature reached 1750°C, and the average grain size is about 25 μm.
出处
《核动力工程》
EI
CAS
CSCD
北大核心
2003年第6期545-550,572,共7页
Nuclear Power Engineering
基金
2000年度中国核动力研究设计院青年基金资助
