Nuclear power has become a major factor in supplying the electric energy needs of the world. The scientists and engineers who brought nuclear power from laboratory discovery to commercial applications relied heavily on theorectical analysis of system performance. One reason for this is that the learn-by-experience approach involving numerous pilot plants is costly and potentially dangerous with nuclear reactors. An aspect of plant performance that has been analyzed extensively is the dynamic and safety behavior of the system. The results of these studies have had a strong influence on plant designs and on operating policies.

Now that a number of plants are going into operation, the opportunity to check the predictions is available. Some tests have been performed, but there has been too little emphasis on verification of theoretical reactor dynamics calculations by appropriate tests and only a small part of the available information has been extracted from most of the tests that have been performed. Procedures are available for performing dynamics tests on power reactors with very small cost and with insignificant interference to normal operation. Also, methods for interpreting the results to provide a great deal of information on system characteristics are available. The use of existing test procedures and interpretation methods along with the develop­ment of more advanced methods are in the best interest of safe and efficient power reactor operation.

The specific measurement emphasized in this monograph is the determina­tion of the system frequency response using nonsinusoidal input perturba­tions. Nonsinusoidal perturbations are useful because normal power reactor hardware (such as control rods) can be used. Frequency response results are convenient because the interpretation is simple, correlation with theoretical results is straightforward, and the results can be used directly in control system design or modification.

A great deal of work has gone into the development of procedures to design, implement, analyze and interpret such tests. The newcomer is likely to be overwhelmed if he tries to gather and digest the reports and papers on this subject. This monograph is intended to collect and cull the required information.

The analysis required for these tests involves numerical Fourier trans­formations using analog or digital equipment. Fourier analysis is basically a very simple process, but users have shown great ingenuity in finding ways to do it incorrectly. Much of the material in this book is intended to steer the analyst around the multitude of traps.

The contributions of my colleagues and students are gratefully acknow­ledged. In particular, S. J. Ball of Oak Ridge National Laboratory and J. C. Robinson of the University of Tennessee are thanked. Also the co­operation of Duke Power Company, Babcock and Wilcox Company, and Carolina Power and Light Company in the application of the procedures described in this monograph is gratefully acknowledged. Wes Kerlin and Randy Pasqua are thanked for suffering through the preparation of the illustrations.