摘要
锆合金在压水堆中常用作包壳材料,而包壳的腐蚀限制了燃料的堆内使用寿命。为了增加核燃料的燃耗,有必要研究包壳的腐蚀过程。以秦山一期核电厂乏燃料棒为研究对象,对包壳外表面氧化膜的内应力和物相组成进行分析,对径向氧化膜显微形貌进行观察。结果表明,氧化膜中存在压应力,从燃料棒底端到顶端,应力逐渐减小,当降低到最低值时,应力逐渐稳定下来,最后在气腔处又突然增加;压应力对稳定四方相有着非常重要的作用,随着氧化层中裂纹与孔洞的发展,应力得到释放,氧化膜的物相逐渐转变为单斜相。
Zirconium alloys are often used as nuclear fuel cladding in pressurized water reactors. Oxidation of these alloys is a limiting factor in the lifetime of the fuel. To extend the burn-up of the nuclear fuel requires the control of the corrosion, it is necessary to study the cladding corrosion process. The composition and the residual stress of the oxide films of the spent fuel rod from Qinshan Power Plant Phase Ⅰ were investigated by XRD method and stress measurement instrument. The results indicate that the compressive stress exists in the oxide film, and the value decreases gradually from the bottom to the top of the fuel rod. However, the stress at the air chamber suddenly increases after it gradually stabilizes at the minim value. Also, the stress has very important effect on the stability of the t-ZrO_2, and the composition of the film gradually transforms to the monoclinic phase along with the releasing of the stress caused by the development of cracks.
出处
《核动力工程》
EI
CAS
CSCD
北大核心
2017年第S1期105-109,共5页
Nuclear Power Engineering
关键词
乏燃料棒
锆合金
氧化膜
内应力
Spent fuel rod
Zirconium
Oxide film
Residua stress
