Experience has been obtained with a continuous neutron-noise monitor at the High Flux Isotope Reactor (HFIR) and with neutron- and pressure-noise monitors at the Molten Salt Reactor Experiment (MSRE). Results at the HFIR show that the neutron-noise monitor can be used to detect con-tro I-rod-bearing failures. The neutron-noise monitor at the MSRE gave a continuous indication of the amount of helium void in the fuel salt circulated through the core. The value of noise analysis as a diagnostic aid was shown when the pressure-noise monitor at the MSRE aided in a diagnosis of off-gas line restrictions one week before other instruments confirmed the blockage. These experiences show that noise analysis can be used for some types of reactor malfunction diagnoses and parameter measurements when other methods cannot be used either because of the environment (radiation or temperature) or a lack of space for sensors.