Betova Iva, Bojinov Martin, Karastoyanov Vasil
Institute of Electrochemistry and Energy Systems, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria.
Department of Physical Chemistry, University of Chemical Technology and Metallurgy, 1756 Sofia, Bulgaria.
Materials (Basel). 2023 Mar 24;16(7):2577. doi: 10.3390/ma16072577.
Oxidation of Zr-1%Nb fuel cladding alloy in simulated primary coolant of a pressurized water nuclear reactor is followed by in-situ electrochemical impedance spectroscopy. In-depth composition and thickness of the oxide are estimated by ex-situ analytical techniques. A kinetic model of the oxidation process featuring interfacial reactions of metal oxidation and water reduction, as well as electron and ion transport through the oxide governed by diffusion-migration, is parameterized by quantitative comparison to impedance data. The effects of compressive stress on diffusion and ionic space charge on migration of ionic point defects are introduced to rationalize the dependence of transport parameters on thickness (or oxidation time). The influence of ex-situ and in-situ hydrogen charging on kinetic and transport parameters is also studied.
采用原位电化学阻抗谱对锆 - 1%铌燃料包壳合金在压水核反应堆模拟一回路冷却剂中的氧化过程进行跟踪。通过非原位分析技术估算氧化物的深度成分和厚度。通过与阻抗数据进行定量比较，对氧化过程的动力学模型进行参数化，该模型包括金属氧化和水还原的界面反应，以及由扩散 - 迁移控制的电子和离子通过氧化物的传输。引入压应力对扩散的影响以及离子空间电荷对离子点缺陷迁移的影响，以解释传输参数对厚度（或氧化时间）的依赖性。还研究了非原位和原位充氢对动力学和传输参数的影响。
