A computer vision approach for dynamic tracking of components in a nuclear reactor core model

Abstract

The Advanced Gas Cooled Reactors (AGRs) are a vital component of the UK's electricity supply system. Their continued reliable operation is supported by safety cases that include assessments of their seismic resilience to their ultimate lifetimes. These assessments are developed via a complex programme of numerical simulations, physical modelling and shaking table testing. A quarter sized physical model representing a single layer of an AGR graphite core was developed at the University of Bristol (UOB) to test the dynamic response for various core array configurations and seismic excitations. The dynamic displacement response is significant, as displaced components may cause local or general distortions that could theoretically affect the channel shapes and the keying system of an AGR core, with implications on the fundamental functions of the reactor. This paper presents a computer vision approach for component displacement mapping. An infrared vision system and a highresolution video system were employed to track all the components in the model core during a seismic event. The systems have proven to be fit for purpose, being able to map the position of the array components at a resolution of 0.1mm and to reveal features of response that are useful for understanding the core dynamics. The employed hardware and tracking algorithms are general in nature, hence they are transferrable to other case studies involving multi-body assemblies under dynamic loading.

Shaking Table Test of a Full Scale Three-Leaf Masonry Wall

“…The data acquisition system consisted of a combination of Infrared Vision instrumentation together with high speed video (HSV) [28] for tracking, in real time, the position of reflective markers mounted on the specimen (Figure 12a). This system worked in parallel with the accelerometer data collected by a conventional data acquisition (DAQ) system.…”

A Surrogate Machine Learning Model for Advanced Gas-Cooled Reactor Graphite Core Safety Analysis

“…Examples include the computational model Parmec (Koziara, 2019) and the physical Multi-Layer Array (MLA) (Dihoru et al, 2014) at the University of Bristol. Both of these represent a simplified version of the true AGR graphite core, scaling the geometry to one-quarter of the true volume and reducing the number of channels and levels.…”

A mathematical framework for evaluation of column shape profiles for an advanced gas-cooled reactor core model subject to seismic excitation

“…The MLA is a quartersized AGR-core like structure consisting of 8 layers of 20 bricks arranged to match the octagonal layout of an AGR core (Dihoru, 2017). Significant experimental testing, modelling and analysis has been employed over the past decade on the MLA core model (Dihoru et al, 2020(Dihoru et al, , 2019(Dihoru et al, , 2018. For this testing the MLA model (Figure 1) was mounted onto the shaking table at the University of Bristol and subjected to a range of seismic and harmonic input motions to investigate the response of the array to different seismic events.…”

“…During testing, the seismically induced motions of bricks within the MLA are monitored using a variety of embedded sensors (Dihoru et al, 2017). In addition, the motion of the top of the brick columns are monitored using motion capture infrared vision tracking and high resolution camera systems (Dihoru et al, 2019). Displacements of measured interfaces and brick column tops are crucial in evaluating the full dynamic response of a stacked column housed within the MLA core model.…”