Incore neutron noise analysis

A variety of applications for PWR incore neutron noise measurements is examined. In-core noise spectra have proven valuable for interpreting other process spectra and providing a means of monitoring the mechanical performance of fuel assemblies. All structural and fuel assembly motions detected in these investigations have been very small and have no adverse effect on plant operations. The global temperature oscillation is insignificant with respect to system design limits and presents no operational problems. This work has shown that noise analysis of incore detector signals has a direct application in reactor system surveillance and diagnosis. (auth)