Fuel assembly, and grid rack and supporting insertion piece thereof

Abstract

The invention relates to a supporting insertion piece for a grid rack of a fuel assembly, the grid rack used for the fuel assembly, and the fuel assembly. The supporting insertion piece comprises a tubular end part and a plurality of spaced supporting parts, wherein each supporting part extends along the axial direction of the tubular end part, one end of each supporting part is connected with the tubular end part, and the other end of each supporting part is not fixed. The supporting insertion piece has a gap, and the length of the gap along the axial direction is at least equal to the axial length of the whole supporting part, so the gap is sufficient to accommodate a strip so as to realize fixed mounting; and thus, the strip can be directly inserted into the gap without arrangement of a slit in the strip. Since the supporting insertion piece is cooperated with the strip via the gap in the supporting insertion piece, the buckling strength of the assembled grid rack can be greatly improved; and thus, destroy to fuel rods during accidents (such as earthquakes) can be effectively abated and resisted.

Description

technical field [0001] The present invention relates to nuclear reactors and in particular to a support insert for a grid of fuel assemblies, a grid for fuel assemblies and a fuel assembly. Background technique [0002] The grid of the fuel assembly in the nuclear reactor includes a plurality of strips, the strips intersect and cooperate with each other to form a plurality of grid units, and the fuel rods are arranged in a grid unit along the longitudinal direction. To better restrain and support the fuel rods, there are support inserts on the straps. figure 1 An exploded view of a strip and insert 22 of the prior art is shown, the support wall 30 of the insert 22 is fixed on the strip by being inserted into the slit 48 of the strip, here it is required to be on the strip A slit for receiving the insert is provided, and the length of the slit 48 is substantially equal to the height of the insert 22, only slightly smaller than the height, so this will have an adverse effect ...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is to provide a support insert for the grid of the fuel assembly, aiming at the defect that long slits need to be set on the strips in the prior art, which adversely affects the buckling strength of the grid. components, grids for fuel assemblies and fuel assemblies

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