Abstract
This work describes the application of noise analysis techniques to study the unsteady core flow patterns in four loop plants. The study is focused on the determination of the position of the flow perturbations and their causes. The analysis was performed using sampled data collected from a four loop plant instrumentation that included the loop flow rates, the ex-core neutron detectors and the core exit thermocouples. As part of the analysis, the thermocouple signals were cross-correlated to the flow data to determine approximate flow perturbation mappings in the core. The results of the analysis illustrate the value of noise analysis as a tool for the characterization of the flow conditions in the core.
