MICROSTRUCTURAL MODIFICATION OF UO_2-5wt CeO_2 SINTERED PELLETS AND DERIVATION OF THERMAL CONDUCTIVITY AFTER THERMAL SHOCK

摘要

Uranium and uranium-related ceramic oxide fuel pellets are widely used in nuclear power reactors currently in operation for electricity generation. These oxide nuclear fuels developed so far and being used in the reactors have advantages over the metallic fuels; e.g., stable phases with high melting point, good compatibility with coolant and stability against neutron irradiation. Certain disadvantages of these materials are, however, the lower thermal conductivity than that of metallic fuels, which affects, their thermo-physical and thermo-mechanical properties and, as a consequence their in-reactor performance. Currently, technologies are being developed for the improvement of such properties, especially when these oxide fuels are subjected to higher burn-ups.