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High-Temperature Gas-Cooled Reactor

Gas-Cooled family · Generation IV · Demonstration

Contested

Helium-cooled, graphite-moderated reactors using robust TRISO fuel particles that retain fission products at very high temperatures — enabling process heat and strong passive safety.

How it works — schematic
🚧 Diagram in progress
Containment Reactor vessel Graphite + TRISO Helium Heat exchanger Steam Turbine G ⚡ grid Condenser
Runs very hot — ideal for industrial heat.

Simplified schematic for orientation, not an engineering drawing — we're actively refining these for accuracy.

Key specs

Coolant
Helium
Moderator
Graphite
Fuel
TRISO particles
Spectrum
Thermal
Outlet temp
~750–950 °C
Status
Demonstration

Real-world examples

  • • X-energy Xe-100
  • • China HTR-PM
  • • Project Pele microreactor
Strengths
  • + Very high outlet temperature (industrial heat)
  • + TRISO fuel is meltdown-resistant
  • + Passive safety
Trade-offs
  • – Graphite handling
  • – Lower power density
  • – Fuel cost