Home · Fusion vs SMRs
Comparison

Fusion vs small modular reactors (SMRs).

Both promise compact, firm, carbon-free power. The difference is the fuel and the waste: fission SMRs split heavy atoms and leave long-lived waste; fusion fuses light ones and can't melt down.

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Side by side

Splitting vs fusing.

Fission SMR
Small modular reactor
  • Splits uranium/plutonium — a self-sustaining chain reaction
  • Long-lived high-level waste and proliferation controls
  • Mature, licensable technology deploying this decade
  • Firm, carbon-free baseload
Kronos
Kronos fusion
  • Fuses light isotopes — no chain reaction, cannot melt down or run away
  • Low-neutron burner: scheduled-replacement waste near zero
  • Also makes strategic materials the U.S. can't source at scale
  • Firm, carbon-free — prototype targeted 2030, fleet 2036+

Fusion isn't a drop-in replacement for fission — it's cleaner, unmeltable, and it makes fuel and materials on the side.

Verify it yourself

Open by design.

Live simulation
Run the engines
Open →
Open data
Zenodo · CC BY 4.0
Open →
How it works
The two machines
Open →
Learn (Fusion 101)
Go deeper
Open →
Is fusion safe? →Is fusion clean? →Firm power for the grid →
Go deeper

See how Kronos works.

Two machines, in the open.

How it works →
Conceptual design and simulation study; the integrated Kronos machines are not yet built, and certain results are requirement-class. No financial figures are published on this site.