Structure of the pellet-cladding interaction layer of a high-burnup Zr-Nb-O nuclear fuel cladding

JOURNAL OF NUCLEAR MATERIALS

卷:556

Article

Liu, Xiang¹  Cinbiz, Mahmut Nedim¹  Kombaiah, Boopathy¹  He, Lingfeng¹  Teng, Fei¹  Lacroix, Evrard² 

[1] Idaho Natl Lab, Idaho Falls, ID 83415 USA

[2] Framatome Inc, Lynchburg, VA USA

关键词: Neutron irradiation;    Zr-nb-o alloy;    Pellet-cladding interaction (pci);    Interaction layer;    Zirconium oxide;    Transmission electron microscopy (tem);    High-burnup fuel;    post-irradiation examination (PIE);   

DOI  :  10.1016/j.jnucmat.2021.153196

来源: Elsevier

【 摘 要 】

Structure of the pellet/cladding-interaction (PCI) layer of a high-burnup nuclear fuel with niobium bearing cladding was investigated using modern transmission electron microscopy (TEM) techniques. Morphology of the PCI consisted of uniform zirconia layer on the cladding side and finger-like features towards to the ceramic fuel. The PCI layer showed a complex microstructure that constitutes three distinct zirconia layers formed by two zirconia phases. From cladding to fuel, monoclinic, tetragonal, and another tetragonal phase were determined via TEM diffraction patterns and precession electron diffraction (PED) using ASTAR microscopy platform (AMP). Characterizations showed that monoclinic and tetragonal phases close to the cladding were crack-free, but the tetragonal layer adjacent to the fuel contained cracks and pores. Presence of the monoclinic layer suggested that its formation involved the gaseous diffusion of oxygen below threshold dose of fission product damage before the fuel/cladding contact occurred. Furthermore, high-resolution TEM revealed compound phase of (U,Zr)O-2 at fringes of zirconia fingers on the fuel side. Published by Elsevier B.V.

【 授权许可】

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