フリースタンディング式使用済み燃料ラックの準三次元運動モデルの構築

抄録

Apurpose of this research is to develop a simplified dynamic model for a free standing spent fuel rack (FS rack) and to propose design guidelines of the FS rack. The FS rack is designed to suppress a movement caused by seismic excitation due to fluidstructure interaction effect of clearance flow between a neighboring rack and wall of a storage pool as well as due to friction between rack pedestals and bottom surface of the pool. Therefore, the FS rack under earthquake excitations probably shows various motions such as translation sliding, rotation sliding, and rocking. In this research, we developed a quasi-3-dimensional dynamic model for a single FS rack by combining two 2-dimensional numerical models, the translational-and-rotational model, and the rocking model. To validate the proposed model, an experiment with a 1/16 scale reduced model of the FS rack was performed and the results were compared with the calculated results. Then, the full-scale FS rack under the actual acceleration of the earthquake wassimulated by using our proposed model. As a result, it is found that coefficient of friction has an important role in the behavior of the FS rack and kinetic coefficient of friction might be changed by the effect of rocking vibration.