Dynamic response of nuclear power plant generating unit at simulated seismic excitation

Three synchronized Vibroseis generators placed outside the reactor building were used to simulate seismic effects on the generating unit of the Dykovany nuclear power plant. The excitation force showed a sine waveform with a continuously changing frequency. The vibrations were transmitted to the pressure vessel via the subgrade and the reinforced concrete foundations. The measured data show the relation between the amplitude of induced vibrations of the pressure vessel and the magnitude of simulated seismic activity. This relationship may be used for determining the stress of various nuclear power plant equipment during an earthquake and for determining its earthquake resistance. The experiment also verified the suitability of used instruments, measuring methods and evaluation procedures. The measured values were used for deriving certain constants for mathematical models used in the calculation of structures. (Z.M.)