zavire shiran

Factorio: uranium production ratios

there you are, building a megabase. you have a magnificently overengineered nuclear powerplant, with automated fuel insertion when your steam buffer is getting low, perfect ratios, and enough refined concrete to pave a small country. now all you need to do is figure out how much uranium mining and uranium processing you need to keep it going at full blast.


per 1 reactor you will need:

multiply by the number of reactors you will be running and round fractional centrifuges up.


to make the fuel cells that the nuclear plant runs on, you need your stockpile of uranium to be 1 part U235 to 19 parts U238. since uranium processing produces 235 at much lower rates than this, you need kovarex processing to make up the difference. get it circuited up to balance whatever stockpile you are using for nuclear power at the correct ratio. make sure your fuel cell production is also circuited to not eat into your U235 buffer for kovarex in case you have supply problems.

i will be ignoring modules and any buffering needs, so make sure you have sufficient buffer to keep things going (e.g. kovarex, etc.).

calculation explanation

each fuel cell burns for 200 seconds and costs 1 U235 and 19 U238. reprocessing the spent cell returns 3 U238, which is precisely the amount of U238 needed to run one cycle of kovarex (it's almost like they planned it that way). this means that you will need 1 cycle of kovarex for each reactor every 200 seconds. since both nuclear fuel reprocessing and kovarex processing is 60 seconds, 3 centrifuges of each per ten reactors will handle your U235 needs.

since uranium processing gives so much more U238 than the necessary ratio, we will begin by assuming the uranium processing only gives U238. each reactor needs 19 U238 every 200 seconds. once centrifuge can produce 16.667 U238 per 200 seconds, which mean you need 1.14 centrifuges per reactor (57 centrifuges to 50 reactors exactly, or 6 to 5 if you are doing it close enough).

the 19 U238 will require 190 uranium ore, which is 0.95 ore/s per reactor, or 19 ore/s per 20 reactors.