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Considering the background related to the corrosion of highly irradiated nuclear fuel discussed earlier, the differences in corrosion rates under various water chemistry conditions are quite significant, and they represent one of the key factors affecting the corrosion behavior of highly irradiated nuclear fuel. I. Differences in corrosion rates under different pH conditions: At low pH levels, in acidic, low-pH solutions rich in MgCl₂, the corrosion rate of UO₂ fuel with high burnup reaches its peak value, which is much higher than that under neutral conditions; this facilitates the conduct of accelerated dissolution experiments. Neutral/weakly alkaline conditions: In synthetic groundwater with a pH of ≈8.1, uranium and plutonium rapidly reach dissolution saturation, and the leaching rate of uranium is significantly suppressed, being only a fraction of that in low pH conditions. Highly alkaline conditions: Excessively high LiOH concentrations can destroy the protective oxide film on the surface of the zirconium alloy cladding, significantly increasing the corrosion rate of the cladding. II. Differences in reaction rates under different redox conditions: Under aerobic conditions, the UO₂ matrix is easily oxidized to uranium oxides with higher oxidation states, resulting in a significant increase in the dissolution rate. Reduction condition: When a reduction environment is created using an H₂/Ar mixture, the leaching rate of fuels with high combustion rates decreases significantly, falling well below the values observed under oxidation conditions. III. Differences in corrosion rate under different conditions of dissolved impurities: By maintaining the dissolved oxygen level below 0.5 mg/L, the corrosion rate of zirconium alloy cladding can be reduced by more than one order of magnitude compared to environments with higher dissolved oxygen levels. Between different coolant solvent systems (deionized water, NaCl solution, MgCl₂-enriched solution), the corrosion rate of highly irradiated fuel can vary by several times to dozens of times.