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

The present work explores the potential of Gd2Zr2O7 for incorporation of ThO2 and Al2O3 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 Gd2-yThyZr2-yAlyO7 are single phasic in nature and beyond y>0 4 the biphasic region starts The solubility of thoria in Gd2Zr2O7 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 Gd2Zr2O7 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 (C) 2010 Elsevier B V All rights reserved