Abstract: Methods for technical diagnostics and inspection of pipelines to detect leaks in nuclear power plants pipelines. Acoustic signals are recorded within a broad ultrasonic range at two points along the pipeline length located on the pipeline downstream and upstream of a valve. The recorded ultrasonic signals are then processed and used to construct two signal spectra. Then the range of 15,000 to 90,000 Hz is isolated, and the highest amplitude value in both signal spectra is selected within this range. Then the amplitudes of the signal spectra within the said frequency range are divided by the highest amplitude value, and the difference between the signal spectra upstream and downstream of the valve is determined using a mathematical formula, thereby determining the degree of the pipeline leak-tightness.

Abstract: A method for measuring vibration acceleration in three mutually orthogonal planes via vibration sensors. Vibration accelerations are measured at the monitoring points on an operational and knowingly fault-free diesel generator, and then vibration accelerations are measured at the monitoring points of a diesel generator in the course of its operation with prescribed intervals. Temperature and intensity of an ultrasonic signal are additionally measured at the same monitoring points, and the root mean square values of the ultrasonic signal intensity, temperature and vibration acceleration are determined. The measured vibration acceleration values are used to calculate the root mean square values of vibration velocity and vibratory displacement, the distances between clusters of preceding measurements are determined, and a conclusion on the operating state of the diesel generator is made. The method promotes timely detection of any operating defects through periodic measurements and comparison of calculations.

Abstract: Methods for diagnostics of electrically driven equipment and monitoring of vibrations in rotating equipment at nuclear power plants. The methods include measuring and recording of diagnostic signals, dividing the recordings of a reference signal and the signal from the equipment under inspection into segments, converting each segment of the recordings of the reference and inspection signal into a spectrum which represents the distribution of amplitudes across frequencies, sampling amplitudes of the diagnostic signal spectra from the inspected and fault-free equipment at the frequencies where deviations appear between the inspection and reference signals, calculating absolute amplitude difference in the spectra, ranking of the absolute differences and summarizing the ranks.