The Bero research project aims to develop a method for sampling inaccessible areas. Specifically, this involves the drainage pipes beneath the reactor of a nuclear power plant. These are straight pipes made of mirror-welded polypropylene embedded in reinforced concrete. The aim is to obtain approval for installation by taking samples from the inside of the pipes, thereby avoiding the need for removal. Due to the adhesive bond between the pipes and the surrounding concrete, removal of the pipes is only possible at great financial and mechanical expense. Within the project, various approaches are being pursued and different prototypes are developed. These are intended to use various tools to take reproducible samples at a defined location within the pipe. To be able to make a qualitative statement about possible impurities and contamination, it is crucial that the sample taken is as homogeneous as possible and that the material properties of the pipe remain unchanged. However, individual methods for striping the surface present various difficulties when dealing with polypropylene. The different processes result in varying restoring forces, electrostatic charging, and different levels of heat generation. In order to investigate the problems mentioned above, a test rig including measuring systems was set up as part of the project. This enables different tools to be examined in terms of their suitability. By analyzing the influence of different tool specifications and operating parameters, a system can be developed that is geared towards solving the problem.
Gack et al. (Thu,) studied this question.