Oxidation behavior of zircaloy-2 cladding tube under axial temperature gradient

Ioka, Ikuo  ; Kato, Hitoshi; Ogawa, Hiroaki  ; Yoshida, Hiroyuki  

When the function of cooling system for a spent fuel pool loses, the spent fuel pin put under vapor and air environment. Oxidization of the spent fuel pin is considered to be the severe conditions, which have axial temperature gradient including an air-water interface. The oxidation behavior of the zircaloy-2 with axial temperature gradient was investigated. The oxidation test was carried out at 600C among saturation water vapor. The axial temperature gradient was about 10C/mm. The amount of hydrogen gas was measured during the examination, and the oxide film was analyzed. The amount of hydrogen gas decreased to about 100 ppm after increasing rapidly in early stages of the examination. Although oxidization by a temperature gradient increased the amount of hydrogen a little, there is no remarkable difference in oxide-film thickness.