Can Japan’s nuclear power plants be safe from another earthquake?

Japan is one of the countries with frequent earthquake and other natural disasters. Since the Fukushima nuclear power plant accident caused by the tsunami caused by the East Japan earthquake in 2011, Japan has attached great importance to the safety of nuclear power facilities. < / P > < p > according to Li Yinsheng, in order to achieve high-precision seismic performance evaluation of nuclear power facilities, it is necessary to reproduce the three-dimensional shape of nuclear power facilities and establish a three-dimensional detailed seismic safety evaluation model, so as to master the overall and local vibration conditions of plant, equipment and piping system. < / P > < p > in order to reflect the three-dimensional vibration characteristics of the plant, it is necessary to obtain the detailed information of the seismic response of the foundation, floor and wall of the nuclear power plant, so it is necessary to increase the location and number of seismometers. Due to the limited number of natural earthquakes, it is necessary to carry out active observation to obtain more dynamic data. < p > < p > Li Yinsheng told Science and Technology Daily that the Japan Atomic Energy Research and development agency has established a three-dimensional seismic evaluation model for nuclear power facilities based on the high temperature gas cooled test reactor, and established a large-scale seismic observation system to master the seismic response in cooperation with the Japan Atomic Energy Administration. The reason for HTTR selection is that the plant building is the same size as commercial light water reactor, and the existing seismic observation system can be used. < / P > < p > the seismic observation system based on HTTR expands the existing seismic observation system, and 32 permanent seismometers are set on the foundation, floor and factory wall, which can be used for long-term seismic response observation of 96 components in three directions. In addition, the mobile seismograph can be set at any place in the facility to master the detailed vibration response of important machines and pipelines. In addition to the observation in the event of a natural earthquake, an artificial seismograph is also set up, which can be combined with permanent and mobile seismographs to conduct active seismic observation at the required observation time and location. According to Li Yinsheng, the system can also observe the response of artificial earthquakes on the basis of observing natural earthquakes. This system is the first in the world that can simultaneously observe the response of large-scale natural and artificial earthquakes to nuclear power facilities.