Development of Post-Irradiation Test Techniques for the Components of a Nuclear Fuel Assembly in Hot Cell(I)

The mechanical properties of the components of a nuclear fuel assembly is degraded during the operation of the reactor, through the mechanism of irradiation damage. The properties changes of the components supporting the fuel rod in the fuel assembly should be quantitatively estimated to ensure the safety of the fuel rod during the operation. The test techniques developed in this report are used to produce the irradiation data of the grid 1x1 cell spring with fuel cladding, the grid 1x1 cell, the spring on one face of the 1x1 cell, the inner/outer strip of the gird and the guide tube. The ability of handling the fixtures and the specimens by a manipulator and the reliability of test results in hot cell were considered for the design of fixtures and apparatus. The testing machine should have a capability of the compressive loading and unloading at a constant loading rate and up to a given deformation level. All the fixtures was designed and installed so that the loading line should be coincide with the centerline of the specimen during each test. Through these tests of the components, the essential data on the fuel assembly design could be obtained. These results will be used to update the irradiation behavior databases, to improve the performance of fuel assembly, and to predict the service life of the fuel assembly in a reactor