TEST SYSTEM FOR EVALUATING SPENT NUCLEAR FUEL BENDING STIFFNESS AND VIBRATION INTEGRITY

摘要

A reversible pure bending test system has been developed to support an NRC research project. The test system can be used to test and characterize static bending stiffness as well as the vibration integrity of spent nuclear fuel. The reversible bending is conducted utilizing a U-frame setup with the push-pull force applied at the loading point. The U-frame setup can be integrated into the test machine in either vertical or horizontal layouts. The deformation of the rod specimen is measured directly using three-point deflection, and therefore the curvature of deformed rod specimen can be easily estimated. The functionality of the test system has been demonstrated using surrogate rods in out-of-hot cell tests. The relationship of total strain versus the number of cycles to failure exhibits a well-defined trend. It has been further shown that flexural rigidity can be used as an index to characterize the integrity of the SNF.