Nuclear fuel assembly and method of assembling same

Abstract

The present application discloses a nuclear fuel mechanism and an assembling method thereof, which can reduce the flow-induced vibration of the lower end plug of the fuel rod in the horizontal direction. The adjusting member drives the connecting member to move, so that the anti-foreign matter plate moves horizontally relative to the seat body. At this time, the central axis of the constraint through hole of the anti-foreign matter plate is dislocated with the central axis of the constraint counterbore of the seat body, so that the limiting part of the lower end plug of the fuel rod is limited below the anti-foreign matter plate. By limiting the limiting part of the lower end plug of the fuel rod between the anti-foreign matter plate and the seat body, the axial movement of the fuel rod is limited. When the clamping force of the positioning grid loses, the axial movement of the fuel rod under the action of the hydraulic lifting force or the axial impact load of the fuel assembly is prevented, the aggravation of the fretting corrosion of the grid and the fuel rod is avoided, and the fuel rod failure caused by the falling impact of the lower tube seat is avoided.

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