Review of Detecting Anomalies in Power Reactors Using Neutron Noise Analysis

Core diagnostics has been a key component of nuclear reactor operation to ensure reactor safety and performance. As a multicomponent system, perturbations in nuclear reactors are unavoidable. This article reviews neutron noise, and its definition and application to nuclear reactors. Our review finds that neutron noise has been integral to nuclear reactor operations. Multiple experiments using reactor data have been conducted to measure the perturbations that can happen to a nuclear reactor. Implementation of neutron noise analysis provides some insight into the perturbations that can happen in a reactor, effectively providing a means to diagnose all the phenomena in a nuclear reactor system.Seeing the benefits of conducting noise experiments, computational models of neutron noise have been developed. In the first years, the development focused on defining the neutron noise sources from reactor operations. Neutron noise theory and solutions were developed from the neutron transport theory for power reactor systems.This article reviews the derivation of neutron noise using diffusion theory, which simplifies neutron transport theory, and some computational tools developed to solve such problems. This article also reviews implementation of machine learning for neutron noise analysis. Although it has promising prospects, it still requires some available data from operating reactors or sufficiently high-fidelity simulations to train the model. Another area that can benefit from neutron noise analysis is diagnostics for Generation-IV (Gen-IV) reactors.As new types of reactors have been developed over the years, and especially with the development of Gen-IV reactors, new kinds of perturbations, which can happen to those systems, might arise. Some new methodologies could be developed to identify the noise sources in the systems of advanced reactors, and eventually implemented for computational analysis of neutron noise for advanced reactors.