APPARATUS AND METHOD FOR MEASURING GAP OF USED NUCLEAR FUEL ROD

摘要

PURPOSE: A method of measuring the gap of a used nuclear fuel rod and a device thereof are provided to simplify the test procedure and measure multiple points, and to improve the accuracy of the measurement by minimizing the error. CONSTITUTION: In the method of measuring the gap of a used nuclear fuel rod, in step one, the tester has the gap of the fuel rod before use and the compression strength of the clad. In step two, the pressure of the fluid pressure system is set so that a weight of 10 percent less than the compression strength is imposed on the gland. In step three, the used rod(9) is placed horizontally on a load cell(10). In step four, the end of the ax-type gland of the fluid compression cylinder(7) should touch the upper part of the fuel rod(9) and adjust the pointer until the load cell(10) reads zero. In step five, the tester opens the valve for direction change of the cylinder(7) to descend the cylinder load. Here, the weight of the fuel rod(9) is measured at the load cell(10) and the potential change is measured at the micrometer probe(5), and the results are drawn as a graph by a computer(14). In step six, the tester close the valve(15) to raise the cylinder load, reads the graph and, if the peak of the weight does not show up, repeats step five by increasing 3 to 5 percent of the weight of the rod(9) until a peak appears.