New approach to the decay ratio estimation in B.W.R. N.P.P.: frequency-moments technique

The aim of this work is to develop an alternative method of evaluation of basic characteristics of neutronic flux oscillations in nuclear reactors, like the decay ratio (DR). fundamental frequency, etc. This approach is rooted in the classical method of moments, and is a development of the one previously suggested for plasma diagnostics. A physical model of neutronic flux oscillations is presented and the parameters for this model are determined in a consistent way. The method is validated using the signals of a simulated oscillator. Finally. this methodology is applied to the neutronic signals of Ringhals NPP.