Extreme Conditions

The plasma contained in a Tokamak fusion reactor creates some of the most inhospitable conditions on Earth, with extremes of temperature, high magnetic fields, and dangerous radiation. These conditions present a series of enormous engineering challenges for developing new infrastructure which can operate in such an environment in the long term. Equally, this presents an opportunity to adopt improved safety and monitoring protocols by employing cutting edge inspection techniques, early in the design process.

Full Matrix has developed a condition monitoring system for performing guided wave ultrasound inspection of a Tokamak reactor cooling system .

Coolant pipes for the divertor are an example of critical infrastructure which is exposed to extremes of radiation and high temperatures, and therefore require careful monitoring for damage. Guided wave ultrasound techniques allows remote inspection of a large distance of pipework with hardware confined to a safer region.

Even at a remote distance from the reactor, the pipework is anticipated to experience temperature swings up to ~600°C. Hence, the inspection system has been designed around high-temperature, contactless EMAT transducer hardware, which is not reliant on couplant (which would be expected to degrade under thermal cycling). Contactless measurements can therefore be performed consistently over time, with improved reliability over the lifetime of the infrastructure.

Complex Geometries

The path of the divertor coolant pipes is beset with a sequence of bends, in order to navigate amongst the densely packed components and instrumentation. As a result, the path of ultrasonic guided waves is a complex one, and any measurement must compensate for the geometry of the pipe. For this reason the Full Matrix inspection system employs a digital twin based approach to focus acoustic energy at a specified location, individually addressing the elements of each EMAT array. This approach improves the detection resolution and negates the difficulties resulting from deviations in the signal path.