Investigations into Dust Waste Treatment for Nuclear Fusion
The generation and accumulation of dust in future nuclear fusion reactors pose challenges related to safety, waste management and environmental impact. Dust, flakes and droplets form because of plasma-facing component erosion, with highly tritiated and activated materials accumulating in-vessel and during decommissioning activities. Estimations for dust generation in ITER predict substantial quantities of tungsten, stainless steel and boron-based particulates, raising concerns about tritium retention, dust mobilization and disposal constraints. 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, analysing the oxidation and adhesion behaviours 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 minimising 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 both reactor maintenance and waste processing. Dust baskets in the MDF successfully contained dusts, although some loss and agglomeration occurred. VIM trials demonstrated 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 fusion dusts, supporting long term waste management solutions for nuclear fusion.