Detecting and Monitoring Operational Events Around a Nuclear Reactor Using Seismo-Acoustic Signals

Date: 4/26/2019

Time: 04:15 PM

Room: Elliott Bay

There are more than one hundred nuclear reactors operating in the United States, making it the world’s largest producer of nuclear energy. Around two-thirds of these reactors generate 20 percent of the total electricity in the country and the rest are used for research or training purposes. Operating a nuclear reactor involves multiple procedures and complex systems of interrelated machines. If we consider as an operational event any change in status (initiation, interruption, and termination) or configuration (change in power, speed, or frequency) of said machines, then many of these events are characterized seismically and/or acoustically by transient or permanent changes in the spectral distribution of energy. In particular, recorded seismo-acoustic signals can be used to detect and monitor these operational events. To demonstrate this idea, we have deployed a three-component seismic station with three acoustic sensors close to the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) for more than a year.

We developed an approach for the automatic detection of operational events based on identifying statistical changes in the spectral distribution of energy compared to a spectral baseline. We applied the power spectral density (PSD) based detection algorithm to continuous seismo-acoustic data and compare the results with operational ground truth logs. The algorithm not only finds the timing of detectable operational events but also the frequencies of the associated seismic/acoustic signal. Furthermore, we developed interactive visualization tools to examine the results in detail. Preliminary results show a good agreement between the PSD detections and ground truth for several operational events.

Presenting Author: Chengping Chai

Authors