An Experimental Demonstration of Nuclear Instrumentation Surveillance in Power Reactors

An experimental program demonstrating the feasibility of two in-situ, on-line surveillance techniques developed as part of an ongoing research program is described. The surveillance techniques tested include noise analysis methods which measure the high frequency power spectral density (PSD) function of neutron detector output signals. and measurement of sensor response to a step perturbation in the high voltage bias applied to the detector. Selected results of tests performed at two operating power plants are presented. Neutron sensors tested include source, intermediate, and power range monitors which are a normal part of the plant RPS.