A study on dynamic behaviors of integrated reactor internals about an earthquake

Reactor internals show dynamic behaviors when they are affected by various dynamic loads such as earthquakes and flow induced vibration (FIV). The structural integrity assessment evaluates these response behaviors in order to prevent accidents and the seismic analysis identifies the dynamic behaviors from the seismic loads. The seismic analysis should be performed during the design process in order to secure safety of the reactor internals and the reactor should be manufactured considering the results of the seismic analysis. The System-Integrated Modular Advanced ReacTor (SMART) developed in Korea is an integrated pressurized water reactor which contains main components in the one reactor vessel. In this research, a methodology of the seismic analysis with the integrated reactor internals is suggested. The simplified finite element (FE) models, which reflect dynamic characteristics of the reactor internals, are constructed for the seismic analysis. In order to validate these simplified models, the reliable dynamic characteristics of the reactor internals extracted from the scale-down model are used. Moreover, the time history analysis is conducted with the verified seismic model in order to obtain the dynamic behaviors of the reactor internals. These results are used to evaluate the structural integrity of the reactor internals.