Vibration of PWR internals considering their edge conditions and holes

In this paper the results of a study of the frequency modal characteristics of PWR core barrel models either without holes, either with the holes, both in air and in still water, are presented. Experimental studies of the influence of holes on the frequency spectra and on the values of damping coefficients in mentioned environments, and of the end seating behaviours were carried out. As far as the research in a fluid flow is concerned the results of an analysis of hydroelastic response of internals due to random excitations of a coolant flow and a built hydrodynamic equipment, which contains the gravitational channel of 36 m water column, are described. (orig.)