Releases of anthropogenic radionuclides from European nuclear fuel reprocessing plants enter the surface circulation of the high-latitude North Atlantic and are transported northward into the Arctic Ocean and southward from the Nordic Seas into the deep North Atlantic, thereby providing tracers of water circulation, mixing, ventilation, and deep-water formation. Recent work has benefited from advances in accelerator mass spectrometry to enable the measurement of the conservative, long-lived radionuclide tracers 129I and 236U, that added to the former use of 137Cs. Latest studies of these tracers include the use of transit time distributions (TTDs) to accommodate circulation timescales and mixing, providing a rich inventory of transport data for circulation in the Arctic and North Atlantic Oceans that are of great importance to global thermohaline circulation and climate. During this seminar, I will present a summary of the work we have been doing at ETHZ in the last decade and the future plans within the TITANICA project.