Scientists are exploring the potential of deuterium and tritium, two hydrogen isotopes, to revolutionize energy production through nuclear fusion. These isotopes are considered the most effective nuclear fuel for fusion devices, offering the promise of limitless clean power generation. Deuterium, readily distilled from various water sources, is a widely available and virtually inexhaustible resource, while tritium, produced during fusion reactions through lithium interaction, remains a fast-decaying radioelement occurring in trace amounts in nature. The Tritium Laboratory Karlsruhe in Germany is at the forefront of safe tritium handling and fuel cycle research, crucial for commercial fusion power generation. Technical challenges associated with the tritium fuel cycle are being addressed, with a focus on storage, injection, exhaust gas processing, and establishing efficient purifying and recycling systems. Advanced technologies like permeation barriers and isotope separation systems are being developed to enhance tritium plant performance. Additionally, end-of-lifecycle solutions are being explored to minimize contaminated waste. The Karlsruhe Tritium Neutrino Experiment, operating since 2018, has gained global recognition for its contributions to neutrino mass measurement. With significant achievements in tritium circulation and purity, the laboratory is setting new standards in tritium research and development.