T₀ = 15 °C · Tk = 600 °C · Tc = 15 °C. Sodium-cooled fast reactor · Na primary 550 °C · Na secondary · steam at 487 °C. IHX = intermediate Na–Na heat exchanger (safety function). SG includes economiser (9.8 %), evaporator (5.4 %), superheater (11.5 %). Full balance: s4e2.com/exerg/SUPERPHENIX_EB.pdf