Development of internal vibration monitoring system for NPP based on neutron noise technique

The vibration monitoring system for internal structures developed for Qinshan Nuclear Power Phase II Extension Project is able to monitor the vibration of reactor pressure vessel and internal structures, which comprises four acceleration and eight neutron noise channels.Several modern techniques are applied in the system, for instance, FPGA are adopted in signal preprocessing; PXI bus technology are applied for the synchronization processing between channels and modules; Original data is stored in a standard form and an open entry is supplied; The signal analysis tools include time field, auto-power spectrum density, cross-power spectrum, coherence and phase are provided for the vibration analysis. The system can monitor the vibration of pressure vessel, core barrel and fuel assemblies, and etc. (authors)