Investigations into the development of a new type of internal pipe cutting device for difficult to access pipelines

Abstract Following the German government’s decision to phase out the use of nuclear energy after the reactor accident in Fukushima in March 2011, 27 prototype and power reactors are currently undergoing a dismantling process in Germany. No nuclear power plants have been in operation in Germany since April 2023 (BMUV – Bundesministerium für Umwelt 2023). The dismantling of pipelines, which are difficult to access from the outside due to limited space or because they are installed in concrete structures, is associated with many challenges and additional work for the personnel on site. Among other things, there is no universal pipe cutting system that can be used to separate pipes made of different materials, diameters and wall thicknesses from the inside of the pipe. Additional functions such as remote operation or the ability to decontaminate the machines, are of great importance for use in a nuclear environment. Most of the devices available on the market focus on pipe decontamination and are limited to certain diameters and materials. In addition, the developments are based on conventional applications and must be further adapted to the particular conditions in a nuclear facility (Bachmann 2024). Based on this, the “RoTre” project and the resulting dissertation examined the internal pipe cutting process with disk cutters, circular saw blades and cut-off wheels. The investigations presented are part of the research project “Development of a novel universally internal pipe separator for the dismantling of (contaminated) pipelines (RoTre)”, funded by the Federal Ministry of Education and Research (BMBF).