Based on the long term experience in developing noise diagnostics systems and starting from the successful
KARD system a new system, integrating noise diagnostics and signal validation capabilities has been developed with the financial support of the National Committee for Technological Development (OMFB).The system is able to receive technological data from the standard core instrumentation, performs discretisation, stores the data on disk and performs processing and analysis. Up to 32 data channels can be processed simultaneously (with an option of increasing the channel number to 64). Processing is menu driven and includes Fast Fourier Transform, univariate as well as multivariate AutoRegressive and Moving Average AutoRegressive analyses, Kalman Filtering, Sequential Probability Ratio Testing, Parity Space representation analysis.
The noise diagnostics analysis conforms with the options in the KARD system, i.e. it includes monitoring of reactor core barrel motion, coolant velocity estimation, control rod vibration detection and analysis of effects on the basis of characteristic maxima in the spectra of the measured quantities (temperature, pressure, neutron flux, mechanical vibration).
The system runs on an IBM compatible high performance PC under MS Windows, with modules written in Borland C++. The usual Windows menu system directs the user in a self-explanatory manner. The
displayed schemes represent parts of the technological system in a hierarchically ordered and encapsulated manner. Selection of the sensors to be processed as well as of the methods to be applied is highly flexible and comfortable. The results of the analyses appear automatically in both graphical and textual forms. Long term storage and trending of the results are also options.
Overview of the reactor and of the available functions
Noise diagnostics analysis has lead to the identification of abnormal processes in the core several times in the past. The huge potential offered by the fact that all incore measurements (about 550 signals at every unit) are available through the diagnostics output channels of the incore data acquisition system PDA shall in all probability enhance the role of the noise diagnostics and signal validation methods in reactor core surveillance.
