<![CDATA[Development of the nuclear fuel technology was aimed to improve nuclear power plant efficiency. One of the proposed solutions was utilization nuclear fuel with the high burn up. This leads to an increase in gas fission and nuclear reactor core reactivity. The excess reactivity of the reactor core controlled by integrated fuel burnable absorber. In connection it has made a layered thin UO2 pellets with burnable absorber. The objectives of this research was to obtain the characters of zirconium diboride layer on UO2 pellets surface i.e microstructure, crystal structure and chemical composition. The results of this experiment showed that the microstructure of UO2 + 0.4% Cr2O3 pellet has equiaxial and acicular grains with a diameter of 2.44 mm, whereas the UO2 + 0.3% Nb2O5 pellets has a grain structure in the form of equiaxial and flattened rod with a diameter of 2.47 mm. The layer of zirconium diboride on the surface of UO2 + 0.4% Cr2O3 and UO2 + 0.3% Nb2O5 pellets are similar namely thin and compact with a thickness of 2.71 mm and 2.82 mm. The identification of X-ray diffraction pattern on UO2 + 0.4% Cr2O3 and UO2 + 0.3% Nb2O5 pellets to exhibit there are of UO2 phase with cubical crystal structure and phase ZrB2 phase with hexagonal crystal structure. Meanwhile, zirconium concentration on the surface layer of UO2 + 0.4% Cr2O3 and UO2 + 0.3% Nb2O5 pellets each of 1.82 mg and 1.90 mg, the presence of zirconium element show that ZrB2 layer formed on the surface of UO2 pellets.]]>
