Hydrogen motion in Zircaloy-4 cladding during a LOCA transient

T. Elodie (1) , D. Jean (1) , G. Séverine (1) , B M-Christine (2) , C. Michel (3) , P. Berger (4) , B. Martine (5) , A. Antoine (5)

1 IRSN - Institut de Radioprotection et de Sûreté Nucléaire
2 LaMCoS - Laboratoire de Mécanique des Contacts et des Structures [Villeurbanne]
3 GeM - Institut de Recherche en Génie Civil et Mécanique
4 LEEL - UMR 3685 - Laboratoire d'Etudes des Eléments Légers
5 EDF - EDF

Hydrogen and oxygen are key elements influencing the embrittlement of zirconium-based nuclear fuel cladding during the quench phase following a Loss Of Coolant Accident (LOCA). The understanding of the mechanisms influencing the motion of these two chemical elements in the metal is required to fully describe the material embrittlement. High temperature steam oxidation tests were performed on pre-hydrided Zircaloy-4 samples with hydrogen contents ranging between 11 and 400 wppm prior to LOCA transient. Thanks to the use of both Electron Probe Micro-Analysis (EPMA) and Elastic Recoil Detection Analysis (μ-ERDA), the chemical elements partitioning has been systematically quantified inside the prior-β phase. Image analysis and metallographic examinations were combined to provide an average oxygen profile as well as hydrogen profile within the cladding thickness after LOCA transient. The measured hydrogen profile is far from homogeneous. Experimental distributions are compared to those predicted numerically using calculations derived from a finite difference thermo-diffusion code (DIFFOX) developed at IRSN.

Domains: Chemical Sciences; Material chemistry

T. Elodie, D. Jean, G. Séverine, B M-Christine, C. Michel, et al.. Hydrogen motion in Zircaloy-4 cladding during a LOCA transient. IOP Conference Series: Materials Science and Engineering, 2016, 123, pp.012020. ⟨10.1088/1757-899X/123/1/012020⟩. ⟨cea-01636822⟩