DYNAMIC RESPONSE OF VVER 1000 TYPE REACTOR EXCITED BY PRESSURE PULSATIONS

The paper deals with the modelling of forced vibrations of reactor components excited by pressure pulsations generated by main circulation pumps. For the vibration analysis a new generalised model of the reactor with spatial localization of the nuclear fuel assemblies and protection tubes, continuously mass distribution of beam type components and more accurate model of the linear stepper drives for actuation of control cassettes was applied. Slightly different pump revolutions are sources of the beating which causes an amplification of vibration and possibility of the contact loss in internal linkages of the core barrel.