Christopher Stumm studied electrical engineering with a focus on automation technology at the University of Applied Sciences in Saarbrücken, Germany. He has been working at Fraunhofer IZFP for six years in the field of microwave and terahertz methods, and he currently is especially concerned with high-frequency equipment and algorithmical developments.


Non-destructive characterization of polymers with terahertz systems

Despite Germany's withdrawal from nuclear power, it still plays a decisive role in Europe. On average, about 25,000 cables with a total length of 1,500 km are installed in a nuclear power plant. In parts, these cables are exposed to rough conditions such as high temperatures and radioactive radiation. This can result in ageing of the cable insulation with embrittlement and thus to cracks and short circuits as possible consequences.

Against this background, two projects „TeaM Cables“ and „Polysafe“ were launched as part of the European research programm Horizon2020 as well as research programm by the German Society for Plant and Reactor Safety (GRS). „TeaM Cables“ will develop a novel multiscale approach for more precise estimation of cable lifetime with focus on cables with XLPE as isolation material, which are mainly used in the newer generations of nuclear power plants. The „Polysafe“ project focuses on cables with CSPE/EPR as isolation material, which are more common in current generations of nuclear power plants, for which the designed lifetimes were already or will be exceeded in the next years.

Fraunhofer IZFP’s contribution in these research projects relates to its competence in terahertz spectroscopy; the institute performs measurements using terahertz time domain spectroscopy on artificially aged material samples and real cables. Another focus is to analyze, interpret and correlate the measurement results with reference values to determine age-specific parameters. The advantage of terahertz methods for cable characterization results from the contact-free operation over a distance of many centimeters.

The first results will be shown in the presentation.

Christopher Stumm
Christopher Stumm
Fraunhofer Institute for Nondestructive Testing IZFP