High Temperature Oxidation Behavior of Hydrogen-Charged Zirconium Alloy under High Steam Pressure

Since 1990, improving fuel cycle economy has required an extension of the fuel cycle and higher burnup operation. The modern PWR tend to be operated in the severe operating conditions. Moreover, hydrogen from the dissociation of water molecules during oxidation process can be absorbed in Zirconium alloys resulting in hydrogen embrittlement. To date, some systematical research has been conducted regarding hydrogen behavior in Zirconium alloy, including hydrogen absorption and embrittlement. This research indicated that hydrogen absorption has no great influence on the oxidation of cladding at LOCA (Loss of Coolant Accident). However, most of these studies considered only oxidation temperature and time, regardless of the effect of hydride precipitation under high steam pressure. Therefore, this study investigated the oxidation behavior of hydrogen charged Zirconium alloy cladding under high temperature and high steam pressure. This data will give an exact evaluation of the corrosion of fuel cladding. The results can also be used to prevent the problems arising from hydride precipitation in the nuclear fuel cladding materials