Year
2017
Abstract
In Korea, since the commencement of commercial operation of nuclear power plants in 1978, 25 nuclear power plants have been constructed and operated. They are 14x14, 16x16 and 17x17 Westinghouse type power plants, OPR1000 and APR1400 power plants. Along with the long history of nuclear power generation, various types of spent fuel are stored in spent fuel pool of each power plant, and the storage pools are expected to be saturated in the near future. Therefore, various social discussions and researches are under way to construct a dry storage facility. In order to move and store various kinds of spent fuels to interim storage, the handling integrity of the fuels must be guaranteed. In this study, we have developed a strategy to improve the handling integrity of the spent fuels for future transporting to the dry storage. At first, it has been investigated that the status of the spent fuels stored in spent fuel pools such as the type and its number of fuels, burnup, material of components, connecting methods between top nozzle and guide tube, and the handling load transferring mechanisms according to the connecting method. Based on the investigation, a representative nuclear fuel type was selected, which seemed to be critical in handling integrity point of view among the spent fuels, and the 3-dimensional finite element analysis model was developed using ABAQUS software for the representative fuel assembly. For the verification of the developed analysis model, a series of strength tests were performed with simulated specimens considering hydrogen embrittlement. The analysis results are in quite good agreement with strength test results. Therefore, the analysis model implemented the test results will be applied to the evaluation of the fuel handling integrity reflecting the specific design characteristics of the remaining spent fuel type.