Influence of hydrogen on the oxygen solubility in Zircaloy-4

Effect of pre-oxide and hydrogen on creep of Zircaloy-4 at 1123 K

“…At 1123 K, Zircaloy-4 is in the  +  domain. At this temperature, the amount of  phase strongly increases with the hydrogen content while it is minimally affected by the presence of up to 2 wt% of oxygen [13]. Under equilibrium conditions, the amount of  phase formed in Zy-4 at 1123 K increases with hydrogen content from  20 % in bare materials [14] to  90 % in samples with 1000 wppm of hydrogen [15].…”

Combined effects of temperature and of high hydrogen and oxygen contents on the mechanical behavior of a zirconium alloy upon cooling from the βZr phase temperature range

“…Precisely, after oxidation at 1100 and 1200°C, high oxygen contents, attaining up to 1-1.2 weight % (wt%), equivalent to about 5 atomic % (at%), were measured in the βZr phase in the presence of high hydrogen contents, up to about 3000-4000 wppm, or 20-25 at% [19]. It is important to note that the solubility limit of oxygen in the βZr phase at 1100-1200°C is lower than 0.5-0.6 wt% in the absence of hydrogen [6,21,22]. This correlation between hydrogen and oxygen contents in the βZr phase in the secondary hydrided regions can be essentially related to hydrogen's thermodynamic effect on oxygen solubility and diffusivity in this phase at HT [2,13,21,[23][24][25].…”

“…It is important to note that the solubility limit of oxygen in the βZr phase at 1100-1200°C is lower than 0.5-0.6 wt% in the absence of hydrogen [6,21,22]. This correlation between hydrogen and oxygen contents in the βZr phase in the secondary hydrided regions can be essentially related to hydrogen's thermodynamic effect on oxygen solubility and diffusivity in this phase at HT [2,13,21,[23][24][25].…”

Degradation of Cr-coated cladding under the simulated Loss-of-Coolant Accident phenomena

“…Further from the burst opening, steam starvation might result in massive hydrogen uptake. Hydrogen concentrates in β-Zr phase (β-stabiliser) and can lead to cladding embrittlement due to the oxygen solubility increasing in β-Zr phase [21,22].…”