The thermal conductivity of Nd_2Zr_2O_7 pyrochlore and the thermal behaviour of pyrochlore-based inert matrix fuel

摘要

High-temperature heat capacity and thermal diffusivity of neodymium zirconate (Nd_2Zr_2O_7) were measured by differential scanning calorimetry and laser flash, respectively. Measurements were made on pellets with the pyrochlore structure (a = 1.07 nm) that were fabricated from milled beads obtained by gel supported precipitation. The thermal conductivity, calculated from the measured heat capacity and thermal diffusivity, was lower than that for ZrO_2 stabilised in its cubic structure. These results show that the pyrochlore-type zirconate can be used as an inert matrix for minor actinides transmutation, but only in a composite form.