On the origins and the evolution of the fuel-cladding bonding phenomenon in PWR fuel rods

JOURNAL OF NUCLEAR MATERIALS

卷:520

Article

Ciszak, Clement^1,2  Desgranges, Lionel¹  Garcia, Philippe¹  Sabathier, Catherine¹  Fayette, Laurent¹  Chevalier, Sebastien² 

[1] CEA, DEN DEC, F-13108 St Paul Les Durance, France

[2] Univ Bourgogne Franche Comte, ICB Lab, UMR 6303, CNRS, F-21078 Dijon, France

关键词: Spent fuel;    Zircaloy;    Fuel-cladding bonding;    Model materials;    Diffusion couple;   

DOI  :  10.1016/j.jnucmat.2019.04.015

来源: Elsevier

【 摘 要 】

This study proposes a new and detailed description of the fuel-cladding bonding phenomenon occurring in PWR fuel rods. Very early and late bonding states were characterized on specimens of 35.3 GWd.t(U)(-1) moderate burnup and of 64.5 GGWd.t(U)(-1) high burnup respectively. Results were then compared with those achieved on a re-created bonded situation obtained on a Zircaloy-4/hyper-stoichiometric UO2+x model materials diffusion couple. These results tend to indicate that a chemical adhesion is probably at the origin of the PWR fuel-cladding bonding. In addition, the progressive formation of ZrO2/UO2 interfacial circumvolutions observed with increasing burnup, which lead to the physical anchorage of ZrO2 and UO2, is likely to lead to their mechanical adhesion. Thus, the in-reactor ZrO2/UO2 bonding could be considered, since the occurrence of the first bonded situations, as an adhesion phenomenon owning two components: an initial chemical progressively strengthened by a second mechanical. (C) 2019 Elsevier B.V. All rights reserved.

【 授权许可】

Free