No Steam Cycle: How the Water Demand Disappears
Removing the turbine-condenser loop removes the single largest water demand in conventional thermal generation.
A steam Rankine cycle has four stages: boil, expand through a turbine, condense, pump back. The condenser is the water sink. In a recirculating plant, warm condenser water is sent to a cooling tower where a fraction evaporates to shed heat; that evaporated water is consumed and must be replaced with makeup. In a once-through plant, water is withdrawn from a river, lake, or ocean, passed through the condenser once, and returned warmer.
The burner path
In the burner (Aegis / MetroVolt), fusion products that are charged are slowed against collector electrodes and their energy appears directly as electric current. Because that energy is never thermalized, there is no working fluid to boil and no condenser to cool. The plant's electricity output does not pass through a Rankine cycle at all.
What still needs cooling
- The 5.44% neutron fraction deposits energy as heat in the first wall and blanket.
- Superconducting magnets at 26.49 T plug / 17 T throat require cryogenic cooling.
- Power electronics and the direct-conversion collectors dissipate resistive losses.
- Auxiliary and building loads (HVAC, pumps) exist as in any facility.
These residual loads are real and are engineered with closed cooling loops. The defensible public claim is narrow and true: eliminating the steam cycle eliminates the largest water demand of a comparable thermal plant. We do not publish a single water-intensity number for an unbuilt machine.
One more distinction is worth drawing. Removing the steam cycle also removes the working-fluid chemistry program that accompanies it — feedwater treatment, condensate polishing, and the associated makeup and blowdown streams. Those are not glamorous systems, but they are a meaningful part of a thermal plant's water and chemical footprint, and the burner's charged-particle branch simply does not have them. The residual loops it does keep are small, sealed, and chemically simple by comparison.