EXPERIMENTAL STUDY OF HYDRODYNAMIC EXCITATION OF FUEL RODS VIBRATIONS IN FUEL ASSEMBLY OF WWER-440

EDN: EIJKGI

Authors & Affiliations

Perevezentsev V.V., Solonin V.I.
Bauman Moscow State Technical University, Moscow, Russia

Perevezentsev V.V. – Professor, Dr. Sci. (Techn.), Associate Professor.
Solonin V.I. – Professor, Dr. Sci. (Techn.). Contacts: Bld. 1, block 5, 2nd Baumanskaya St., Moscow, 105005. Tel.: +7 (916) 181-53-70; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it..

Abstract

Vibration processes in nuclear reactors largely determine the reliability of the equipment and the safety of operation of the power unit as a whole. The dynamic effect of the coolant flow on the structural elements of reactor systems initiates and maintains their mechanical vibrations (vibrations). One of the most important mechanical systems that determine the trouble-free operation of WWER reactor plants is the fuel station. Experimental studies are carried out and the results of the characteristics of hydrodynamically excited vibrations of the beam of fuel rods TVS WWER-440 are presented. Experimental data were obtained at the hydrodynamic stand “E7-ELEMASH” using a full-scale (with lead simulators of fuel pellets) model of the WWER-440 TVS of the second generation In order to significantly change the structure of the flow, throttle washers with diameters of 45; 48,5 and 52 mm were placed at the entrance to the fuel assembly model, which are installed in the WWER-440. The results confirmed the determining role in the excitation of fuel rod vibrations not only of the longitudinal velocity, but also of the intensity and spectral composition of the turbulence of the coolant flow. The greatest hydrodynamic loads are formed within the first span between the supporting and first spacer grids. Accordingly, the intensity of vibrations and the likelihood of damage to the shells of fuel rods here is the greatest.

Keywords
WWER, fuel assembly, fuel rods, hydrodynamics, vibration excitation, pressure pulsations, coolant supply path, throttle washers, vortex structures, pressure pulsation spectra and vibration displacements

Article Text (PDF, in Russian)

References

UDC 621.039.546.8

Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, 2022, issue 2, 1:13