Nuclear Furnace

A 5x5 smelter fired by uranium fuel cells instead of the power grid.

What it does

• Burns uranium fuel cells, returns depleted cells. No electricity needed.
• Crafting speed 4, 4 module slots, +50% base productivity (all configurable).
• Smelts everything an electric furnace can, including recipes added by other mods.

Cooling loop (on by default)

• Water in, 500 °C steam out - depending on crafting speed
• Both fluid boxes pass through, so machines can be chained without pipes between them.
• Steam output is not multiplied by productivity.
• Get rid of the steam either way:
• Steam turbine — needs a pump between furnace and turbine (workaround; The pump fixes the different fluids bug)
• Steam condensation in a chemical plant — returns 90 water per 1000 steam. The mod unlocks this recipe with its own technology, so it is available without Vulcanus.
• Fresh water supply stays mandatory in both cases.

Recipes

With the cooling loop on, the mod auto-generates a water-cooled nuclear-smelting variant of every electric furnace recipe. Variants copy the original 1:1 and only add water + steam. Ingredient amounts, result amounts and craft times are unchanged. Each variant is unlocked by the same technology as its original. Recipes that already use a fluid are skipped.

Technology

Nuclear furnace — 1000 × (automation + logistic + chemical + production + utility), 60 s.
Prerequisites: Advanced material processing 2, Nuclear power, Utility science pack, Production science pack.

Crafted from: 1 nuclear reactor, 2 electric furnaces, 50 processing units, 100 steel plate, 20 heat pipes, 100 concrete.

Settings (startup)

Fuel consumption and pollution scales with the crafting speed setting.

Cheaper recipe / Cheaper technology

Both are aimed at Space Age, where the nuclear furnace competes with the foundry and the default costs land late enough to make it a hard sell. They work in the base game just as well.

Compatibility

Factorio 2.1. Space Age optional (adds heating on Aquilo and lets the foundry build it). Modded smelting recipes are picked up automatically; anything in a custom crafting category can be registered through the API.

API for mod authors

Recipes in a crafting category no vanilla furnace knows are not picked up automatically. Opt in from any data stage file:

if mods["nuclear-furnace"] then
  local nuclear_furnace = require("__nuclear-furnace__.api")
  nuclear_furnace.add_source_category("my-smelting")  -- every recipe in this category
  nuclear_furnace.add_source_recipe("my-recipe")      -- this one recipe, any category
end

Both take a prototype name and return false when it was rejected outright. Registrations made before Nuclear Furnace builds its variants are collected and processed in that one pass; anything registered afterwards, which includes the data-final-fixes of every mod depending on this one, is converted on the spot.

Conversion follows the same rules as for vanilla recipes: a recipe that already uses a fluid is skipped, because the cooling loop claims both fluid boxes.

With the cooling loop turned off there are no variants at all. A registered category is then handed to the furnace directly, and a registered recipe gets nuclear-smelting added to its own categories.

Recommended mods

• Assembling Plant — an endgame assembling machine
• Chemical Complex — an endgame chemical plant
• Plasma Beacon — an endgame beacon

AI

Mod concept & design by Morlot.
Implementation developed with the help of Claude (AI assistant by Anthropic).