NSUF 18-1538: Electron microscopy characterization of fast reactor MOX joint oxyde-gaine (JOG)

The objective of this work is to evaluate the microstructure and chemical composition of the fuel-cladding chemical interaction layer (FCCI) using cutting-edge characterization techniques such as high resolution Transmission Electron Microscopy (TEM). The formation of the FCCI layer at high burnup, including possible localized enhanced cladding corrosion, is one of the main life-limiting phenomena of the fast reactor fuel pins. In particular, formation of Cs- and Mo-rich oxide layer has been reported in literature, known as joint oxyde-gaine (JOG). The composition and physical properties of the JOG/FCCI influence several safety- and performance-relevant parameters. For instance, the thermal expansion behavior of Cs2MoO4, thought to be the main component in the JOG, has been studied by Wallez et al. [1], showing large thermal expansion coefficient and high anisotropic behavior compared to the fuel's one. The difference could imply detachment of the JOG film and the possible release of cesium radionuclides in accidental situations [1]. Knowledge of the composition and microstructure of the FCCI layer is therefore of paramount importance to support reliable design and performance analysis. Limited data have been reported on the composition and morphology of the JOG, and no data at sub-micrometric level have been reported so far. This work will employ a series of advanced characterization tools (i.e., SEM/EDX/EBSD and TEM) to fully characterize the FCCI layer at nanometric scale, previously not accessible. The FCCI layer thickness, chemical composition, grain morphology and orientation will be characterized using SEM, EDX and EBSD, with focus on the JOG. SEM/EDX/TEM investigations will highlight fission product segregation or presence of eventual porosity. Local intergranular cladding corrosion will be investigated too. The combined use of several characterization tools will provide a comprehensive mapping of the status of the FCCI layer, and will leverage NSUF instrument capabilities available both at IMCL laboratory. SEM, EDX, EBSD and TEM analyses will be performed at IMCL. The data produced will contribute in understanding and quantifying the physical property changes of the fuel gap due to the FCCI layer formation which affects fuel performance. [1] G. Wallez, P.E. Raison, A.L. Smith, N. Clavier, N. Dacheux, J. Solid State Chem. 215 (2014) 225-230.

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필드	값
Abstract	The objective of this work is to evaluate the microstructure and chemical composition of the fuel-cladding chemical interaction layer (FCCI) using cutting-edge characterization techniques such as high resolution Transmission Electron Microscopy (TEM). The formation of the FCCI layer at high burnup, including possible localized enhanced cladding corrosion, is one of the main life-limiting phenomena of the fast reactor fuel pins. In particular, formation of Cs- and Mo-rich oxide layer has been reported in literature, known as joint oxyde-gaine (JOG). The composition and physical properties of the JOG/FCCI influence several safety- and performance-relevant parameters. For instance, the thermal expansion behavior of Cs2MoO4, thought to be the main component in the JOG, has been studied by Wallez et al. [1], showing large thermal expansion coefficient and high anisotropic behavior compared to the fuel's one. The difference could imply detachment of the JOG film and the possible release of cesium radionuclides in accidental situations [1]. Knowledge of the composition and microstructure of the FCCI layer is therefore of paramount importance to support reliable design and performance analysis. Limited data have been reported on the composition and morphology of the JOG, and no data at sub-micrometric level have been reported so far. This work will employ a series of advanced characterization tools (i.e., SEM/EDX/EBSD and TEM) to fully characterize the FCCI layer at nanometric scale, previously not accessible. The FCCI layer thickness, chemical composition, grain morphology and orientation will be characterized using SEM, EDX and EBSD, with focus on the JOG. SEM/EDX/TEM investigations will highlight fission product segregation or presence of eventual porosity. Local intergranular cladding corrosion will be investigated too. The combined use of several characterization tools will provide a comprehensive mapping of the status of the FCCI layer, and will leverage NSUF instrument capabilities available both at IMCL laboratory. SEM, EDX, EBSD and TEM analyses will be performed at IMCL. The data produced will contribute in understanding and quantifying the physical property changes of the fuel gap due to the FCCI layer formation which affects fuel performance. [1] G. Wallez, P.E. Raison, A.L. Smith, N. Clavier, N. Dacheux, J. Solid State Chem. 215 (2014) 225-230.
Award Announced Date	2018-09-17T12:02:41.38
Awarded Institution	None
Facility	None
Facility Tech Lead	Alina Zackrone
Irradiation Facility	None
PI	Fabiola Cappia
PI Email	[email protected]
Project Type	RTE
RTE Number	1538