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New metrological facilities for high temperature measurements of thermophysical properties have been recently developed by European National Metrology Institutes (NMIs). This work, performed in the framework of the joint research project “MetroFission”, aims to provide reliable measurements up to 2000^\circ C for materials having thermal properties similar to those required for design of new generations of fission reactors. This will enable to improve the traceability to the International System of Units (SI) of measurements performed by nuclear research laboratories. The validation of these reference apparatuses was done at high temperature by measuring the thermal diffusivity and normal spectral emissivity of an isostatic graphite and pure tungsten. [ABSTRACT FROM PUBLISHER]

Abstract: Nitride compounds are currently considered as possible fuels for advanced nuclear reactors. Among the relevant properties to be investigated, thermophysical quantities such as heat capacity and thermal diffusivity/conductivity are key to ensure safe operation of the fuel in the reactor. Both physical and chemical phenomenological experimental activities are included in this effort. The experimental procedures were optimized to limit oxidation of materials in presence of even small quantities of oxygen and moisture, especially during the measurements at high temperature. Heat capacity and thermal diffusivity/conductivity were measured for ZrN and (Zr,Pu)N compounds. A consistent set of results was obtained from low- and high-temperature C p measurements for both materials. The excess C p of solution was estimated. Increasing trends with temperature were observed for the thermal diffusivity and conductivity of both materials in the temperature range considered, confirming the metallic behavior of this class of materials. The presence of Pu causes an almost constant decrease of the thermal conductivity compared to the pure ZrN matrix. [Copyright &y& Elsevier]