Gd2Zr2O7 pyrochlore: Potential host matrix for some constituents of thoria based reactor’s waste

Abstract The present work explores the potential of Gd 2 Zr 2 O 7 for incorporation of ThO 2 and Al 2 O 3 which are components of Advanced Heavy Water Reactors (AHWR) waste. XRD studies reveal that the compositions corresponding to y from 0.0 to 0.4 in Gd 2− y Th y Zr 2− y Al y O 7 are single phasic in nature and beyond y > 0.4 the biphasic region starts. The solubility of thoria in Gd 2 Zr 2 O 7 pyrochlore could be enhanced by more than five times by simultaneous incorporation of alumina. The lattice parameter increases with increase in Th and Al content in the series. The r A / r B ratio increases with increase in Th and Al content in Gd 2 Zr 2 O 7 and in turn the degree order increases as has been seen by gradual increase in the intensity of superstructure peaks. Single phasic samples were investigated by Raman spectroscopy also. Thermal expansion behavior of single phasic samples was investigated by HT-XRD. In order to confirm the nature of the phases backscattered images have been recorded on all the samples.