SPACER GRID OF A NUCLEAR FUEL ASSEMBLY TO PREVENT FLOW-INDUCED VIBRATION

摘要

The present invention relates to a spacer grid for a nuclear fuel assembly capable of reducing flow-induced vibration by improving the structure of a grid plate of a protection space grid. The spacer grid (100) including a dimple (110) for supporting a fuel rod includes: a plurality of flat grid plates (101) which make up each unit grid cell. Each grid plate includes at least one hole (130) separately from the dimpl. As a result, the pressure difference between two cross sections of the hole is reduced when cooling water flows in, and the friction between the cut cross section and the water reduces the size of vibration and brings a damping effect, resulting in reduction of flow-induced vibration. Furthermore, the hole formed on the grid plate distributes the range of the number of flow-induced vibrations of vortex at the end of the grid plate so that the possibility of resonance with the natural frequency of the spacer grid can be reduced.