Analysis of porous features in zirconia based inert matrix, impact on the material qualification

Pore size distribution, porosities and consequently derived densities are key parameters for the qualification of inert matrix fuel (IMF). Porous features must be determined accurately for assessing the in-pile behaviour of the fuel. The analytical methodologies to measure porosities are revisited. The paper discusses in a comprehensive way the results obtained for simulated or plutonium loaded inert matrix fuel i.e. erbia and ceria or plutonia doped yttria stabilised zirconia, by applying thermodynamic or instrumental approaches. The n-D results (open/close porosities) gained by applying invasive/non-invasive, microscopic/macroscopic, neutron/photon and reflection/diffraction/transmission methods with fluid intrusion or not, are given and discussed for the zirconia based cubic solid solution.