Using outward facing EIT to investigate the properties of cracks present in hollow graphite bricks

S. Pennya, A. Fletchera, , D. Armitagea, A. Peytona, R. Chapmanb, M. Brownc

a School of Electronic and Electrical Engineering, University of Manchester, M60 1QD, UK

bNDT Consultant, Dursley, Gloucester, GL11 4EW, UK

c EDF Energy, Barnwood, Gloucester, GL4 3RS, UK

Abstract

This paper discusses the use of Electromagnetic Impedance Tomography (EIT) to detect cracks in graphite bricks from the core of a nuclear Advanced Gas-cooled Reactor (AGR), and to distinguish between the different orientations and depths of the possible cracks. Modelling is done for many different crack profiles, while experimental measurements are taken from five bricks in the lab in order to validate the models. The results of the modelling show a definite relationship between the voltages measured and the crack depths. The experimental results also show the detection of some of the cracks.

Keywords: Non-destructive testing, Electromagnetic Induction Tomography, Image reconstruction, Graphite