Abstract
The fuel rod supporting structure of spacer grid is the key to ensure the horizontal and axial position of the fuel rod. On the purpose of improving the neutron economy and simplifying the manufacturing process of the spacer grid, the innovative curved dimple and arched spring have been designed, which could be directly punched from the strip of spacer grid. The mechanical experiments have been performed to acquire the deformation-load curves of dimples and springs on single strap and in-cell supporting structure, which could provide the load and residual deformation at 100% and 120% designed nominal deformation. It has been demonstrated that the designed in-grid cell has a relative stable load at the 100% nominal designed deformation and the test method of the single stripe is representative for the similar load-deflection curve between the spring and the in-grid cell.
