Detritiation Research for JET Decommissioning

The Joint European Torus (JET) has been the centrepiece of the United Kingdom’s fusion industry and has pushed the boundaries of fusion research for decades. After 40 years of operations, JET ceased operations in December 2023 and was handed over to the JET Decommissioning and Repurposing (JDR) program. As fusion energy is regarded as a sustainable clean energy that leaves no burden to future generations, it is of great significance to demonstrate the feasibility and sustainability of fusion decommissioning.JET will be the second DT (deuterium-tritium) machine ever to be decommissioned, which will require innovation in many areas, including the removal of tritium from the materials and waste (detritiation). The decommissioning of JET will generate waste that will be challenging to dispose of for ~100 years, mainly due to the presence of tritium. Therefore, detritiation will be an important part of the intermediate-level waste management strategy.This paper describes the detritiation research, focusing on the thermal treatment activities that have been carried out under the JDR program. The results suggest that most metals can generally be detritiated at temperatures lower than 800°C; however, considering the expected 3H concentration in the JET materials, multiple thermal treatments will likely be required. This implies that the JET structural assemblies, consisting of different materials, could potentially be treated without prior segregation or disassembly. This would significantly improve the waste processing throughput and reduce the overall cost for the JDR program.