SFR
Sodium-cooled Fast Reactor
Sodium-cooled fast reactor (SFR) uses liquid sodium coolant for fast spectrum breeding with high thermal margins.
Sodium boils at 883°C, enabling high temps; designs like 4S (10-50 MWe) or ASTRID (600 MWe). US EBR-II ran 30 years. Metallic or oxide fuel.
Why it matters now
SFRs lead Gen IV demos; TerraPower Natrium (345 MWe) eyes 2026 Wyoming build with storage for data center flexibility.