The feasibility of a new approach for pipe inspection has been explored using digital twins to enhance guided wave inspection. Guided wave inspection is well-established in the oil and gas industry to screen remotely long lengths of predominately straight pipeline for corrosion. However, inspection of complex geometries of pipe remains a challenge. Nuclear fusion facilities are one such potential application. Fusion reactors will have a network of many kilometres of service pipes with complex features including multiple pipe bends. Some of these pipes could be use for actively cooling components such as the First Wall and Divertor.
Guided ultrasonic wave inspection has the significant advantage of offering 100% coverage of the pipe wall over tens of metres of pipe from a remote test location. This is highly attractive, particularly in the nuclear industry where it is important that human presence in high risk areas is prohibited due to high radiation doses and temperatures. In this work, finite element wave propagation models have been investigated as digital twins of fusion reactor components. The models have been used to calculate bespoke excitation signals that will allow full volumetric inspections of these complex pipes to be carried out from a remote location.
For the first time, it has been demonstrated that models can be used to successfully correct for the distortion caused by multiple pipe bends. This has resulted in an improvement to detection capability by an order of magnitude over a conventional guided wave set-up. The digital twin technique developed here therefore shows significant promise for future inspection of nuclear fusion power plant pipes.