Cody A. Dennett et al. list the following ARC materials challenges (Dennett and Ferry 2023):
- Corrosion mitigation and control from molten salt coolant
- High particle and heat flux divertor heat exhaust
- High temperature structural materials with high dose radiation effects
- Monolithic joining of refractory plasma facing materials to structural materials
- Remote joining of advanced structural materials
The UK Atomic Energy Authority has a reference radial materials build for a DEMO-like fusion. The components listed are:
- Divertor
- Armor (which appears to be another name for the first wall)
- Fusion breeding blanket
- Blanket cooling pipes
- Vacuum vessel
- HTS magnets Each of these is ranked along:
- Neutron radiation
- Temperature
- Heat flux
- Magnetic stresses from coils
- Corrosion
- Mechanical load
- Helium generation
- Cooling fluid pressure
- Plasma erosion
- Tritium absorption (UK Atomic Energy Authority, and Henry Royce Institute. “UK Fusion Materials Roadmap,” 2021. https://www.royce.ac.uk/content/uploads/2021/09/UK_Fusion_Materials_Roadmap_Interactive.pdf.)
Mohamad Abdallah from Tokamak Energy says: “Materials should have started 10 years ago.” We are far behind! ST-80 will have material samples, but it won’t be a fusion prototypic environment so nobody is too worried. But the first pilot plant is concerning. Tokamak Energy is viewing its first pilot plant as a materials test bed. They will do as much radiation testing as possible, but at the end of the day, they are going to pick a material without being sure how it will survive in the reactor. That reactor will generate electricity to some extent, but nobody knows whether it will shred itself in the process. This isn’t just about materials discovery, it’s also about fabrication, scalable manufacturing at the hundreds of tons level, supply chain! And the need to apply coatings too!