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This post was last edited by Wang Wei2 on 2026-7-15 at 13:06. Building on previous discussions regarding the abrasive failure of nuclear fuel, microsliding wear between the grid and fuel rod cladding caused by high-speed coolant is the primary factor leading to such failures. Over 50% of nuclear fuel-related failures in pressurized water reactors around the world are associated with this issue, accounting for 54.8% of all cases of fuel rod cladding failure. In addition, there are several other key factors that contribute to this effect: The acceleration of galvanic corrosion: A potential difference exists between the zirconium alloy cladding and the springs/rigid protrusions on the grid, which leads to galvanic corrosion. At high burnup levels, neutron irradiation reduces the self-corrosion potential of the zirconium alloy, further accelerating the wear process. Impact abrasion by hard foreign objects in the primary loop: Metal debris and other foreign objects remaining in the primary loop continuously rub against the surface of the cladding as driven by the coolant, rapidly wearing through the tube wall and creating cracks; all of the failure cases related to fuel assemblies being removed in the United States between 2017 and 2018 were caused by this factor. Flow-induced vibration and structural design flaws: Spring relaxation and improper design of the clamping structure can amplify the vibration amplitude of the fuel rods, increase the reciprocating friction at the points where the cladding meets the grid, thereby significantly raising the probability of wear-related failures.