Nuclear Fuel

by GotLag

Modifies nuclear fuel cycle to provide a difference between nuclear weapons production and efficient power generation

a month ago
0.15 - 1.0
3 years ago
Latest Version:
1.1.4 (a month ago)
Factorio version:
0.15 - 1.0
95237 times


Instead of all nuclear power and weapons production running off the Kovarex process, there are now two main fuel cycles that reactors can use, depending on your priorities.
The MOX fuel cycle yields just enough plutonium from reprocessing its waste to regenerate its fuel supply, as long as additional U-238 is provided.
The breeder fuel cycle produces a large plutonium surplus which can be used to produce nuclear weapons or produce more MOX to allow your nuclear industry to expand more rapidly than waiting for U-235 to trickle out of your centrifuges.
Nuclear rocket fuel provides a minor sink for U-235 and plutonium if necessary.

Tech Progression

  1. Nuclear power (Chemical science)
    Fuel production is slow, as only uranium-235 from centrifuges is available to make cells with, and used up cells accumulate.
  2. Nuclear fuel reprocessing (Production science)
    Used up cells can be reprocessed to recover some uranium-238, and a smaller amount of plutonium accumulates.
  3. MOX fuel (Production science)
    Plutonium can now be combined with U-238 to produce more fuel cells. Using this cycle allows a reactor to sustain operations without additional U-235, as long as additional U-238 is provided. Increasing the amount of fuel in circulation (or removing some plutonium for other purposes) still requires additional U-235 from centrifuges.
  4. Plutonium breeding (Production and Utility science)
    Breeder cells and breeder cell reprocessing consume U-238 to produce more plutonium at approximately the same ratio that the Kovarex process produced U-235. This increase in plutonium output allows for more rapidly expanding your nuclear industry, and for producing nuclear weapons at a higher rate.

Changes & Additions

Nuclear Power

  • No change from vanilla: 1 U-235 combined with 19 U-238 yields 10 uranium fuel cells.

Nuclear Fuel Reprocessing

  • Reprocessing spent uranium fuel cells now produces 1 plutonium and 4 uranium-238 per 10 spent cells (1 Pu and 12 U-238 per 20 cells in Classic mode)

MOX Fuel

  • 1 Pu + 9 U-238 produces 10 uranium fuel cells.

Plutonium Breeding

  • 1 Pu + 19 U-238 produces 10 breeder fuel cells. These only provide half as much energy as uranium cells.
  • Reprocessing 10 spent breeder cells produces 6 Pu (4 Pu and 1 U-235 in Classic mode).

Nuclear Rocket Fuel

  • A new technology to unlock nuclear rocket fuel, as Kovarex research is no longer used
  • Also adds an alternative recipe using plutonium instead of U-235

Atomic Bomb

  • Atomic bombs by default now require 5 plutonium instead of 30 U-235. The purpose of this change is to force nuclear weapons production to require an operating reactor, rather than simply mining and processing uranium.
  • This can be changed in the mod's startup options, allowing atomic bombs to be created from plutonium, uranium-235, or either

Kovarex Enrichment Process

  • Disabled by default, can be enabled if you want to use it alongside the breeder cycle, or as preparation for uninstalling this mod

Audio License

Radio Active by Mike Koenig under CC BY 3.0


  • Re-enable Kovarex process in the mod startup options
  • Load and save your game
  • Remove this mod