Confirmation of the seismic resistance of nuclear power plant equipment after assembly

It is shown that the natural frequencies and damping decrements of nuclear power plant equipment can only be determined experimentally and directly at the power generation units (reactors) of nuclear power plants under real disassembly conditions for the equipment, piping network, thermal insulation, etc. A computational experimental method is described in which the natural frequencies and damping decrements are determined in the field and the seismic resistance is reevaluated using these values. This method is the basis of the standards document "Methods for confirming the dynamic characteristics of systems and components of the generating units of nuclear power plants which are important for safety" prepared and introduced in 2012.