Investigations into Dust Waste Treatment for Nuclear Fusion

The generation and accumulation of dust in decommissioning activities pose challenges related to safety, waste management, and environmental impact. This study details inactive trials for two treatment strategies for managing dust waste: high-temperature baking and metal melting. Thermal processing was first examined through thermal treatment trials, analyzing the oxidation and adhesion behaviors of ITER-relevant dusts under air and inert gas conditions. Trials in the Materials Detritiation Facility (MDF) tested the viability of using dust containment baskets to facilitate high-temperature processing while minimizing contamination spread. Parallel to this, metal melting via vacuum induction melting (VIM) was explored as a method for consolidating fine dusts into ingots, mitigating dispersal risks. The results of this work indicate that oxidation affects dust morphology, potentially influencing waste processing. Dust baskets in the MDF contained the dusts, although minor loss and agglomeration occurred. The VIM trials evidenced that fine dusts could be incorporated into ingots. The use of metal containers to seed melting was promising. Tungsten powders were incorporated into melts of stainless steel and Inconel, but presented challenges when mixed with copper. These findings contribute to the development of scalable, safe, and efficient strategies for handling dust wastes, supporting long-term waste management solutions for nuclear fusion.