Uranium

Lore & Background

In the world of Factorio, the player's factory grows outward from a single mining drill into a continent-spanning industrial organism. For a long time, the energy problem is manageable: coal fires steam, steam spins turbines, solar panels catch the sun. But as the factory's appetite for electricity multiplies, the old systems strain. Conveyor belts stutter. Research stalls. The hum of the factory becomes a desperate, grinding whine. Uranium changes the calculus. The ore sits in the ground in pale, crystalline veins, unremarkable until the right technology unlocks its secret. Once processed, it becomes a dense, self-sustaining fuel that feeds the nuclear reactors—massive, humming structures that radiate a faint warmth and emit a low, almost subsonic pulse. The reactors do not flicker with the sun or sputter with coal quality. They simply, relentlessly, produce. For a player who has watched their power grid fail at 3 a.m. during a critical production spike, the first reactor coming online is a quiet, almost sacred moment. There is a particular satisfaction in the uranium chain that other recipes do not quite replicate. It is a chain of transformation: raw stone becomes refined metal, metal becomes engineered fuel, fuel becomes the invisible force that drives ten thousand pistons. The factory, which was once a tangle of belts and furnaces, becomes something closer to a machine with a heartbeat. And that heartbeat is nuclear.

In Their Own Story

The night the first reactor came online, the factory was quiet in a way it had never been before. No clatter of coal shovels. No hiss of superheated steam escaping a cracked pipe. Just a low, steady thrum that you could feel in the soles of your boots, vibrating up through the concrete floor of the control room. You stood at the edge of the reactor enclosure, watching the fuel rod slot accept the processed uranium pellet with a soft mechanical click. The indicator light shifted from amber to a steady, confident green. Power output climbed. And climbed. The solar farm to the east, which had been running at ninety percent capacity just to keep the chemical plants fed, idled down to a lazy twenty percent. The steam turbines, their pistons still warm, slowed to a crawl and then stopped, their flywheels spinning down with a long, satisfied sigh. The factory hummed. Not the strained, overtaxed hum of a system running past its limits. A different hum. Content. Full. Like a machine that had finally been allowed to breathe. You pulled up the production report. Every line green. Every buffer full. The research queue, which had been crawling for three days, began to move again. Somewhere in the distance, a new mining drill started cutting into a fresh patch of iron ore, and the whole sprawling, belt-threaded landscape shuddered with renewed purpose. You made a note in the log: *Uranium chain stable. No further power expansion required until the next tech tree opens.*

Then you went to get a coffee, because even a nuclear-powered factory does not make its own.

Reader's Guide

The uranium production chain in Factorio 2.0 runs from raw ore to reactor fuel in a series of processing stages. **Mining:** Uranium ore appears as a distinct deposit type on the map. It is extracted using a mining drill (advanced or ultimate tier, depending on the specific ore variant). The drill outputs raw uranium ore items onto a conveyor or insert directly into the next processing stage. This is often the initial bottleneck, as deposits are limited and require dedicated drill placement. **Primary processing:** Raw uranium ore is fed into a smelter or chemical processing machine, where it is refined into a usable uranium intermediate. This stage typically requires one processing unit per two to three mining drills at balanced throughput, though the exact ratio depends on your drill speed and smelter speed. **Fuel fabrication:** The refined uranium is further processed into fuel pellets or rods suitable for reactor consumption. This may involve a dedicated fuel-processing machine or a second smelting pass. The output is the final fuel item. **Consumption:** Nuclear reactors accept the fuel and produce electrical energy over a sustained burn period. A single reactor's output can replace a large array of solar panels or steam turbines, dramatically simplifying the power grid. **Scaling and bottlenecks:** At small scale, the mining step is the constraint—there simply are not enough deposits. As the factory grows, the processing stages become the bottleneck, requiring parallel smelters and chemical plants. The chain scales linearly: more drills, more smelters, more reactors. The optimal ratio is roughly one processing unit per mining drill, with a small buffer to avoid starved reactors. In very large factories, the fuel-transport logistics (belts, inserters, storage buffers) become as important as the processing throughput itself.

Did You Know?

• Uranium ore deposits are noticeably rarer on the map than iron or copper patches, meaning players must plan their factory's geography around where the ore actually sits.
• A single nuclear reactor's sustained output can match or exceed the combined output of a large solar farm, making it the most energy-dense power source in the game.
• The uranium chain is one of the few late-game systems where the bottleneck shifts from raw material availability to processing throughput as the factory scales.
• Nuclear reactors produce power continuously regardless of time of day or weather, eliminating the solar/thermal cycling problem that plagues mid-game power grids.