Statistics on Acoustic Effects Registered by LPMS at State-of-the-Art NPP Units Equipped with VVER
New design VVER reactor plants are equipped with the systems of monitoring loose and poorly fastened parts (LPMS). LPMS is intended to detect poorly fastened or loose parts inside the reactor plant primary circuit. LPMS functional principle is based on the monitoring of background acoustic noise of reactor plant equipment. Shocks made by loose or poorly fastened parts against the walls of the hardware produce acoustic anomalies registered by LPMS.
The report provides results of diagnostic data analysis on the basis of the acoustic condition of the main circulation circuit equipment. Major sources affecting the values of stationary background noise are dealt with, dependence of background noise change on the coolant parameters and equipment operating mode is provided.
In addition to loose, poorly fastened and foreign particles, coolant thermal-hydraulic processes and acoustically active equipment running can cause acoustic noise spikes. Registered events are classified and data are provided about the localization of the major sources of acoustic anomalies.
The full report isn't submitted..