Detrended fluctuation analysis of the neutronic power from a nuclear reactor

We have studied neutronic power oscillations in a (BWR) nuclear reactor for three different scenarios. Two of them correspond to stable operating conditions and the third one corresponds to an emergency event where the nuclear reactor showed unstable oscillations that led to a manual scram procedure. Our results show very well-defined power-law scaling properties with long-range correlations for the first two (stable) scenarios, and breakdown of such properties during the emergency event. Some connections between the scaling properties and turbulent two-phase flow patterns in the BWR core are also discussed. Our results suggest that DFA can help in the understanding and monitoring of the dynamics of power generation in nuclear reactors.