Problems of vibrations caused by coolant flow in pressurized water reactor internals

A mathematical model is described for the numerical solution of the stochastic vibrational response of reactor internals excited by turbulent coolant flow, based on the substitution of a continuous assembly by a system with a finite number of degrees of freedom. The frequency and shape of the actual vibration of the considered assembly are usually determined theoretically. For the determination of the size and distribution of the excitation forces for the given reactor internals, theoretical methods are still lacking. It was therefore necessary to build a hydrodynamic experimental equipment with a gravitational channel which is described. Some results are given of the research of the dynamic properties of the model of the core support cylinder. (M.D.)