含铬大晶粒UO_(2)芯块制备  

Preparation of UO_(2)Pellets with Large Grain Containing Chromium

作　　者：王博 刘聪 吴根久 陈煜 WANG Bo;LIU Cong;WU Gen-jiu;CHEN Yu(CNNC Jianzhong Nuclear Fuel Co.,Ltd,Yibin 644000,Sichuan,China)

机构地区：[1]中核建中核燃料元件有限公司,四川宜宾644000

出　　处：《机械研究与应用》2024年第2期63-66,共4页Mechanical Research & Application

摘　　要：大晶粒高热导的UO_(2)芯块为一种理想的高燃耗核燃料芯块。其制备时需在UO_(2)粉末中添加微量Al 2O_(3)和Cr_(2)O_(3),并依照粉末冶金方式来制备。该燃料芯块晶粒尺寸在30μm以上,密度为96.5%~97%T.D,同时为提升芯块导热性,要求Cr含量要在0.06wt%~0.1wt%。制备过程中,首先通过单一添加确定了两种物质的最优添加量,再选择合适的粉末预处理技术对两种物质进行混合添加试验。结果表明,分别添加0.008wt%~0.01wt%的Al 2O_(3)粉末和0.2wt%~0.3wt%的Cr_(2)O_(3)粉末并采用制粒粉末包裹Cr_(2)O_(3)的方式制得的芯块晶粒度可达到43.3μm,密度为96.8%T.D,Cr含量为0.0864wt%掺铬大晶粒UO_(2)芯块。The UO_(2) pellets with large grain and high thermal conductivity is an ideal nuclear fuel pellets with high burnup.According to the design requirements,trace substances Al_(2)O_(3) and Cr_(2)O_(3) should be added in UO_(2) powder and then the fuel pellet is prepared in a powder metallurgy manner so as to ensure that the grain size is over 30μm and the density is 96.5%~97%T.D.At the same time,the residual amount of Cr in the pellet should be 0.06 wt%~0.1wt% in order to improve the thermal conductivity of the pellet.In the preparation process,the optimal addition amount of the two substances is determined by single addition method,and then the appropriate powder pretreatment technology is selected for the mixed addition test.The results show that by adding 0.008wt%~0.01wt%Al_(2)O_(3) powder and 0.2wt%~0.3wt%Cr_(2)O_(3) powder respectively,and using the method of coating Cr_(2)O_(3) with the pelletizing powder,the UO_(2) pellets with large grain containing chromium can be obtained,whose grain size can reach 43.3μm,the density is 96.8%T.D,and the residual amount of Cr is 0.0864wt%.

关 键 词：大晶粒 UO_(2)芯块 Al_(2)O_(3) Cr_(2)O_(3) 

分 类 号：TL352[核科学技术—核技术及应用]