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Small Modular Reactor (LWR-SMR)

Light Water (small) family · Generation III+ / IV · Pre-commercial / first units

Contested

Reactors under ~300 MWe built in a factory and shipped to site. The bet is that series production and lower up-front capital beat the economies of scale of large plants — still unproven commercially.

How it works — schematic
🚧 Diagram in progress
Containment Integral module Integral core Pressurized water Internal SG Steam Turbine G ⚡ grid Condenser
A whole PWR shrunk into one factory-built module.

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

Key specs

Coolant
Water
Moderator
Water
Fuel
Low-enriched UO₂ / HALEU
Spectrum
Thermal
Outlet temp
~300 °C
Status
Pre-commercial / first units

Real-world examples

  • • NuScale (design certified; lead project cancelled 2023)
  • • GE BWRX-300
  • • Rolls-Royce SMR
Strengths
  • + Lower up-front capital
  • + Factory build quality
  • + Sited flexibly
  • + Passive safety
Trade-offs
  • – Loses economy of scale
  • – First-of-a-kind cost risk
  • – Unproven supply chain