Spacer grid with anti-snag and cross action for nuclear fuel assemblies

Abstract

The invention discloses a location grid having hanging prevention and mixing functions for nuclear fuel assemblies. The location grid comprises a grid body, wherein a plurality of strips are interwoven mutually and vertically to form the grid body; the strips are divided into an outer strip and an inner strip; the outer strip is arranged outside the inner strip and is connected with the corresponding inner strip vertically; a plurality of guide wings are arranged symmetrically at the upper end and the lower end of the outer strip; through-holes are formed in the guide wings; and the guide wings are arranged in the joint positions of the inner strip and the outer strip. The outer strip adopts the upper-part guide wings arranged continuously, so that the hanging prevention performance is enhanced; the guide wings with holes can allow a refrigerant to pass through transversely, so that the transverse mixing performance of two adjacent fuel assemblies is enhanced; and the holes of the guide wings reduce the blocking of the flow areas of lattice cells on the opposite side, and can reduce the local pressure loss and increase the thermotechnical safety allowance.

Description

technical field [0001] The invention relates to a positioning grid for nuclear fuel assemblies with anti-hooking and mixing functions, and belongs to the design of the positioning grid for fuel assemblies of pressurized water reactor nuclear power plants. Background technique [0002] The fuel assembly commonly used in the existing pressurized water reactor nuclear power plant is composed of a number of fuel rods, guide pipes, positioning grids, upper and lower nozzle sockets and the like. The positioning grid is an important part of the framework, and its main function is to clamp the fuel rods to make them positioned, and the second is to stir the fluid to increase the critical heat flux density of the fuel assembly. [0003] The traditional positioning grid has guide wings arranged on its outer strips to prevent the fuel assembly from being hooked during the loading and unloading process. Taking the French AFA3G positioning grid as an example, the lower guide wings of th...

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Problems solved by technology

Taking the French AFA3G positioning grid as an example, the lower part of the outer bar is completely neatly arranged, but the upper -oriented wing is an empty layout. According to the experience of changing materials at home and abroad, the layout of the upper -oriented wing makes the positioning grid. There is a greater risk of hooking; on the other hand, the improved AFA3G positioning grid is mainly for the upper -oriented wing anti -hook design, that is, a completely neat arranged in the form of a lower -oriented wing form, but it hinders two adjacent two adjacent two neighbors. The cooling agent between fuel components is mixed horizontally, while increasing the local pressure drop of Bianzhayuan

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