The Effect of Sintering Additive on Grain Growth in UO2 Nuclear Fuel Pellet

Abstract

In this work, a powder with specific chemical and physical characteristics was used and the effect of different additives on grain growth and densification of UO2 pellets were studied. The mixture of powder and additives was pressed and then sintered under hydrogen atmosphere for 6 hours at 1700֩C. The Cr2O3 additive not only increased densification but also severely increased the grain size. Other additives had little effect on grain growth of the nuclear fuel pellets. Sintering behavior and Coarse-grained microstructure formation are discussed in terms of the reduction of Cr2O3 to Cr, the dissolution of Cr2O3 in UO2 and sintering.

Keywords

• uo2 nuclear fuel pellets
• grain growth
• additives
• sintering