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

Highlights: • Quarter-sized physical model of an Advanced Gas Cooled Reactor core. • Shaking table testing. • Computer vision system for component displacement mapping. • Bespoke motion capture software tool based on optical flow algorithm. • Patterns of displacement response for certain component locations and orientations. - 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 high-resolution 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 0.1 mm 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.