Synchrotron X-ray diffraction investigations on strains in the oxide layer of an irradiated Zircaloy fuel cladding

Characterization of the conductivity of metal-oxide interface of zirconium based fuel cladding at low and high burnups

“…The crystal structure of the 9-cycle cladding has been object of a study in the laboratory [43] by synchrotron radiation. The major oxide phase observed has been reported to monoclinic ZrO 2 and a very small ratio of tetragonal has been revealed by Micro-XAS analysis.…”

Raman imaging in corrosion science: High‐temperature oxidation of the zirconium alloys used in the nuclear industry as an example

“…[6,7,14] Moreover, spatially resolved techniques, still X-ray microdiffraction and micro-Raman spectroscopy also evidenced a higher fraction of the metastable t-ZrO 2 along the M/O interface, in the form of a thin submicron layer. [14,19,20,[34][35][36] More in detail, there are thought to be two different populations of tetragonal phase. [19,38] Most often, the tetragonal phase, present in the vicinity of the M/O interface (from now on identified as it-ZrO 2 ) is associated to a protective behavior, transforming to monoclinic grains as soon as they reach a critical size.…”

“…Even this second assumption in itself still seems too restrictive. As a matter of fact, recent studies [33,34] using X-ray microdiffraction suggest that the monoclinic lattice is far from being homogeneously deformed. Some of those spatially resolved studies have shown that both in-plane and through-plane stresses exist in the oxide for films of 1 μm and thicker, with compressive in-plane and tensile out-of-plane components.…”

“…[17,18] Both ZrO 2 polymorphs were identified with local probes, that is, micro-Raman [16][17][18][19] and micro-X-ray diffraction. [33][34][35][36] These two phases can also be identified by more macroscopic methods. m-ZrO 2 is the thermodynamically stable phase in the growth conditions and is always the predominant phase.…”

FLUKA study of the actinides induced irradiation damage in Zircaloy-4 cladding during interim dry storage

“…The nuclear fuel swelling causes the pellet to enter in contact with the cladding originating pellet-cladding chemical and mechanical interactions (PCI): the fuel becomes progressively bonded to the cladding while oxygen migrates from the pellet to the Zircaloy and an oxide layer progressively forms. Different studies have documented the nature of this oxide layer, finding mainly the existence of ZrO 2 in monoclinic, tetragonal and/or cubic phases [19][20][21][22][23][24][25]; strong pellet-cladding bonding through the oxide layer is observed in high burnup fuels [20][21][22]25]. After the end of irradiation (EOI) in nuclear reactor, the volume of the fuel is subjected to further increase as a consequence of the accumulation of helium in the fuel matrix plus the expansion of the lattice parameter induced by the alpha damage [14,15,[26][27][28][29].…”