Non-Linear Stability Analysis of Real Signals from Nuclear Power Plants (Boiling Water Reactors) Based on Noise Assisted Empirical Mode Decomposition Variants and the Shannon Entropy

• Main Authors: Omar Alejandro Olvera-Guerrero, Alfonso Prieto-Guerrero, Gilberto Espinosa-Paredes
• Format: Article
• Language: English
• Published: MDPI AG 2017-07-01
• Series: Entropy
• Subjects: boiling water reactors; density wave oscillations; stability monitor; Shannon Entropy; noise-assisted empirical mode decomposition variants; mode-mixing; Hilbert–Huang transform; instantaneous frequency
• Online Access: https://www.mdpi.com/1099-4300/19/7/359

There are currently around 78 nuclear power plants (NPPs) in the world based on Boiling Water Reactors (BWRs). The current parameter to assess BWR instability issues is the linear Decay Ratio (DR). However, it is well known that BWRs are complex non-linear dynamical systems that may even exhibit chaotic dynamics that normally preclude the use of the DR when the BWR is working at a specific operating point during instability. In this work a novel methodology based on an adaptive Shannon Entropy estimator and on Noise Assisted Empirical Mode Decomposition variants is presented. This methodology was developed for real-time implementation of a stability monitor. This methodology was applied to a set of signals stemming from several NPPs reactors (Ringhals-Sweden, Forsmark-Sweden and Laguna Verde-Mexico) under commercial operating conditions, that experienced instabilities events, each one of a different nature.