Description of capability
Any fusion company that uses FLiBe will need ultra-high temperature materials. Why? FLiBe melts at 450 ºC. But it’s very viscous then. You need 550ºC to be non-viscous. So your hot side needs to be 650 ºC. In practice, more like 750ºC. Vanadium can withstand this, but almost no other structural material can.
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Vanadium alloys were extensively considered for fusion and fission a few decades ago.
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Vanadium are higher yield strength than almost everything except nickel-based alloys, which have high activation in a neutron environment.
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Vanadium has three Achilles’ heels:
- They suck up gases (including tritium) and embrittle
- They can’t be in contact with the plasma because they sputter too much
- They get shredded by molten salts like FLiBe
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Mike Short, Myles Stapelberg, Commonwealth Fusion Systems (Cody Dennett) conceived of a vacuum vessel that is tungsten, vanadium, tungsten, aka “WVWVV”.
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Embodiments:
- Cooling channels in the vacuum vessel
- Vacuum vessel wall itself
- “Neutron gate valve” (add a layer like boron carbide to prevent back-neutrons from coming back through the vacuum vessel)
Key people
Mike Short, Myles Stapelberg, Commonwealth Fusion Systems
Technology Readiness Level (1-9)
2
Needs that this could potentially address
Vacuum vessel materials that can withstand 700 degrees C Heat exchangers that operate at high temperatures without melting or corrosion
Tech specs
Unknown
Estimated time & cost to commercialize
Unknown
Outstanding risks
Unknown