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Based on the background discussed earlier regarding the corrosion of zirconium alloy cladding, the following are the high-risk corrosion conditions that most likely lead to cladding failure: High-temperature and high-oxygen water environments: At temperatures above 300°C and with dissolved oxygen levels exceeding 300 ppb, the chromium coating oxidizes and peels off rapidly; once the zirconium alloy substrate is exposed, the corrosion rate increases sharply, resulting in a reduction in wall thickness and eventual failure within a short period of time. Zirconium-water reaction condition: When the cladding is exposed to a steam environment at temperatures above 1027°C, zirconium reacts violently with water vapor; the oxide layer breaks down, leading to a rapid deterioration of its mechanical properties, which ultimately results in the failure of the cladding. This condition was directly responsible for the core meltdown during the Fukushima nuclear accident. Iodine-induced stress corrosion condition: In a reactor environment at around 350°C, when the iodine concentration exceeds 100 Pa and there is contact stress between the fuel pellets and the cladding, cracks will form and propagate rapidly, ultimately leading to cracking and damage of the cladding. High consumption hydrogen embrittlement condition: After long-term operation, the hydrogen uptake of zirconium alloys exceeds 500 μg/g, resulting in the formation of large amounts of brittle hydrides; under thermal cycle stresses, brittle fracture occurs easily, leading to shell damage.