APPARATUS FOR MEASURING BUCKLING DEFORMATION QUANTITY BY IMPACT LOAD OF FUEL ASSEMBLY GRID

摘要

PURPOSE:To enable quantitative measurement by stabilizing measurement, by providing a pair of non-contact type displacement meters to a pair of target plates for the displacement meters fixed to one surface of a fuel assembly grid in an opposed state at predetermined intervals. CONSTITUTION:A fuel assembly grid 2 is attached to a buffle plate 3 being the structure in a furnace so as to provide a gap and target plates 6, 7 for non-contact type displacement meters 4, 5 are respectively fixed to the fuel rods provided in the front and back surface sides of the fuel assembly grid 1 so as to provide the intervals from the non-contact type displacement meters 4, 5 attached to the plate 3. Then, the distance d1 between the displacement meter 4 and the plate 6, and the distance d2 between the displacement meter 5 and the plate 7 are respectively measured before impact is applied to the grid 2 and, next, the distance d1' between the displacement meter 4 and the plate 6, and the distance d2' between the displacement meter 5 and the plate 7 are respectively measured after impact load is added to said grid 2 and the buckling deformation quantity of the grid 2 is calculated as the difference between distances ¦d1-d2¦ and ¦d1'- d2'¦.