Robot arms dismantle longest-running, most powerful fusion reactor

The UK Atomic Energy Authority (UKAEA) has commenced the decommissioning of the Joint European Torus (JET), the world’s longest-running and most powerful fusion tokamak, following over 40 years of operation. JET notably achieved a record 69 megajoules of energy during a six-second pulse in its final deuterium-tritium experiments in October 2023, with plasma operations ending two months later. The initial phase of the JET Decommissioning and Repurposing (JDR) program involved remotely retrieving 66 plasma-facing components and tiles from inside the reactor. These samples are now being analyzed to understand the physical, chemical, and radiological effects of prolonged plasma exposure on reactor materials. The analysis has revealed significant phenomena such as surface melting and the reverse waterfall effect, which were intentionally induced during JET’s final operational pulses to accelerate and observe damage mechanisms in real time. This unique data is critical for validating predictive computer models for future fusion reactors like ITER and