Mechanical performance evaluation test of spacer grid specimen for integrated reactor fuel

The spring and dimple characteristic test and the static buckling strength test were conducted with 3 kinds of specimen which were developed with new concept of fuel rod supporting. The applied conditions of the tests were adjusted to the actual boundary condition. As a result of the tests, the plastic deformation of the new spring were much smaller than or similar to that of the conventional springs of KOFA even though the specimen had the larger than that of the conventional ones so that the active fuel rod supporting condition can be sustained in the core. The static buckling test, the effective area of H-type unit cell is the largest. Therefore, H-type grid had the largest critical buckling strength than the others, i.e., double grid and swirl grid. If the critical buckling strength is larger, the design has better integrity in case of handling / shipping of the fuel assembly or seismic accident situation. (author). 8 refs., 7 tabs., 40 figs