Kovarex Enrichment Setup with Circuit Control - U-235 Production Guide for Factorio 2.0

40xUranium 235

+

5xUranium 238

→

41xUranium 235

Kovarex enrichment is the key to sustainable nuclear power in Factorio. The standard uranium processing recipe (from ore) only gives you 0.7% U-235 output -- not enough to fuel a nuclear reactor consistently. Kovarex trades U-238 (which you have too much of) for U-235 (which you never have enough of).

Before you can start Kovarex, you need 40 U-235. At 0.7% yield from ore processing, that requires processing roughly 5,714 uranium ore. Here is how to get there:

The bootstrap tip: Run 2-3 centrifuges on standard ore processing while you mine enough uranium. Store the U-235 in a wooden chest next to your Kovarex centrifuge. Once you reach 40, insert all 40 plus 5 U-238 into the centrifuge manually or with a filtered inserter.

Without circuit control, a Kovarex centrifuge keeps running until it runs out of U-238. With circuit control, you can ensure steady U-235 extraction and U-238 recycling.

Basic circuit setup:

1. Connect the centrifuge to a red or green wire
2. Set inserter reading mode to "Read centrifuge contents" (pulse or continuous)
3. Connect the U-235 extraction inserter to the same wire
4. Set the extraction inserter condition: U-235 > 41
5. Connect the U-238 extraction inserter to the same wire
6. Set the U-238 extraction condition: U-238 > 2

This setup keeps exactly 40 U-235 and 2 U-238 in the centrifuge. The excess U-235 (the +1) gets extracted automatically. The U-238 output gets recycled back into the input chest.

For a more advanced design with circuit network control:

• Use a constant combinator to output U-235 = 40
• Connect it to the extraction inserter
• Set inserter: Enable if U-235 (from centrifuge) > U-235 (from combinator)
• This dynamically adjusts extraction based on centrifuge contents

Productivity modules are the only module type that does NOT benefit the Kovarex recipe. The recipe is flagged as non-productivity by design. Speed modules are the clear winner.

Both speed and quality modules work but quality modules in a Kovarex centrifuge produce quality U-235, which cannot be used in fuel cell assemblers (they accept only normal quality items). Speed modules are safer.

• Starting too early: Do not rush Kovarex. Two standard ore-processing centrifuges can accumulate enough U-235 for a bootstrap while your base is still on steam power. Start Kovarex only when you need consistent nuclear fuel.
• Forgetting the U-238 loop: Without recycling U-238 output back into the centrifuge input, your Kovarex setup will stall after a few cycles. Always loop the 2 U-238 output back into the input chest.
• Using filter inserters wrong: A filter inserter set to "U-235" on extraction can accidentally grab the seed U-235 (the 40 that should stay in the centrifuge). Use circuit control to ensure extraction happens only when U-235 > 40.

Kovarex enrichment solves the U-235 scarcity problem with a simple investment: one centrifuge, a circuit wire, and a stockpile of U-238 from ore processing. Start with 3 centrifuges for a steady supply. Use circuit control if you want automated priority management. Speed modules are the only modules worth using.

• Factorio Wiki: Kovarex enrichment process -- Official recipe and mechanics
• Factorio Cheat Sheet: Kovarex -- Ratio diagrams and quick reference
• Reddit: Kovarex circuit designs -- Community designs and comparisons