The major objective of this investigation was to study the possibility of measuring dynamic characteristics of the Experimental Breeder Reactor II (EBR-II) by an analysis of the inherent fluctuations at steady state. Subsidiary objectives were to devise a means whereby detailed signature analyses could be obtained on a routine basis and to interpret these signatures. Relatively simple noise models were developed for the EBR-II which aided in the interpretation of the measured signatures. From this interpretation, it appears that it is not possible to measure the power to reactivity transfer function using inherent noise analysis with the existing EBR-II detection equipment. There exists, however, the possibility that this transfer function, and transfer functions of a similar type, may be measured if thermocouples and flowmeters of a different design and/or location are implemented. Detailed, broad frequency range signatures of two neutron detectors have been obtained at low and high power levels for one run. Also, signatures of a single neutron detector have been processed for several runs. These signatures changed in a complicated fashion from run to run.