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Taking into account the background on zirconium alloy cladding corrosion discussed earlier, the following are the typical operating conditions that can lead to such corrosion: First, high-temperature water environments – A high-temperature water/steam environment of over 450°C significantly accelerates the development of pustular corrosion; the corrosion rate increases exponentially with each 50°C rise in temperature. Under a Loss of Coolant Accident (LOCA), the reactor core is exposed to high-temperature steam, leading to unstable oxidation; the kinetics of this oxidation change from a parabolic pattern to a linear one, resulting in a sharp increase in the corrosion rate. II. Abnormal water chemistry conditions: When the dissolved oxygen level in the coolant exceeds 1000 μg/L, transverse cracks can form in the oxide film, accelerating uniform corrosion and pustular corrosion. Excessive fluoride ions in the coolant, high concentrations of LiOH, impurities such as calcium, magnesium, aluminum, and silicon, suspended particles, or an abnormally high pH value can damage the integrity of the oxide film and induce localized corrosion. III. In-core irradiation and mechanical coupling conditions: A high-irradiation environment induces changes in water chemistry, lowers the self-corrosion potential of zirconium alloys, and accelerates galvanic corrosion and fretting wear. The contact stress between the fuel pellets and the cladding, combined with corrosive fission products such as iodine and cesium, can induce stress corrosion cracking, leading to damage to the cladding. IV. Other special operating conditions: High flow rates of the coolant can erode the protective oxide layer on the surface of the casing, accelerating the corrosion process. When a dense, closed-pore scale forms on the shell surface, it causes a local increase in shell temperature, further exacerbating corrosion on the water side.