Substantiation of seismic stability of power equipment for NPPs under design, operation and construction

The brief review of studies on control and substantiation of seismic stability of various steam-water valves and process equipment (heat exchangers, water-treatment and ventilation systems) used at NPP with WWER-440 and WWER-1000 reactors. In these studies applied are calculation methods for control and ensuring seismic stability of the equipment at its designing stage, control tests of some nature equipment samples on vibrating tables to test calculation methods and specify some characteristics, model investigations using small-scale models, measurements of equipment dynamic characteristics within plant systems and pipe-line for NPPs under operation and construction. As typical examples the results of operational solution of the problem of ensuring seismic stability for the Kozloduj NPP pressurizer and complex investigation of seismic stability of the GZZ-500 main gate valve of the WWER-440 plant are given