On September 27, 2024, the official kick-off of our new project ThORN — Experimental Investigations on Thermo-Osmotic Flow in Clay-containing Materials — took place in Berlin. On behalf of the Federal Office for the Safety of Nuclear Waste Management (BASE), we are investigating thermo-osmotic phenomena in claystones in the context of nuclear waste disposal. We are utilizing data from unique laboratory experiments conducted by our partner BRGM from France. In addition, we have two partners, ANDRA, also from France, and EURIDICE from Belgium, with whom we gain access to underground laboratories in different claystone formations. Together with ANDRA, we will design an innovative in-situ experiment and use it to validate our simulations. The calculation of various experiments, the design and interpretation of the in-situ tests, as well as subsequent scenario analyses for the near- and far-field of a repository, will be carried out using our simulation framework OpenGeoSys.