Diagnostic of Loose Parts Event in Water Chamber of Steam Generator

Abstract

During the hot performance test in a nuclear power plant, the alarm event of the loose parts of the steam generator occurred. In order to explore the alarm cause for the loose parts and evaluate the damage of the equipment, it is necessary to confirm the loose parts in time. By establishing the diagnosis and analysis model of the loose parts, the original data of the loose event is analyzed in detail, and the propagation speed of the loose signal, the quality and energy of the loose parts are estimated. Finally, the harmfulness of the loose alarm event is evaluated. The results show that the loose part in the steam generator is a moving metal part, which is a loose part of the internal structure of the reactor. The impact frequency of the loose part is 8700~9300 Hz, the peak range of impact acceleration is 3g~90g, the propagation group velocity of the loose signal is 3200~3300 m/s, and the mass of the loose part is estimated to be about 0.1 kg. The impact energy is 0.45~0.89 J. The diagnostic results of mass and energy are in good agreement with the actual situation, which shows that the proposed method is effective.