Depleted Uranium

Lore & Background

In the Factorio world, the discovery of uranium ore marked the end of the era when every kilowatt had to be wrung out of crude oil and coal. The nuclear facility—its pale concrete halls, the soft blue glow of containment fields, the steady thrum of turbines—became the visual signature of a factory that had outgrown its modest origins. Depleted uranium, the spent byproduct of fuel refinement, sits in storage tanks beside the gleaming nuclear fuel pellets like a reminder that even the cleanest energy carries a trace of its origin. Fans often note the thematic weight of the nuclear chain: where the early game is all rust, soot, and the clatter of iron smelters, the nuclear era is sterile, precise, and almost surgical. Depleted uranium is the one element in that chain that feels like waste, like the factory exhaling. Yet without the full cycle—ore, processing, refinement, and the byproduct it sheds—the reactor simply does not turn, and the entire late-game production grid grinds to a halt. The aesthetic contrast is part of what makes the nuclear era memorable to players. After years of watching conveyor belts snake through forests and over rivers, the nuclear facility is a sealed, circular structure where the logic of the factory becomes almost biological: feed it uranium, it gives you power, and it gives back depleted uranium as the metabolic residue of that exchange.

In Their Own Story

The chemical plant hummed at a steady 4.2 hertz, a sound Mara could feel in her molars more than hear. She pressed her palm against the cold steel of the containment housing and watched the translucent fluid shift from a pale amber to a deep, exhausted grey as the last of the fissile material was drawn out. The nuclear fuel pellets glowed softly in their racks, ready for the reactor. The depleted uranium drained into the secondary tank with a slow, heavy sigh—thick, metallic, almost reluctant. She logged the batch number, wiped a smear of coolant from the glass, and stepped back. Somewhere beyond the facility's perimeter, the old oil refinery was still coughing black smoke into the evening sky, a relic of a factory that hadn't yet learned to dream in megawatts. Mara smiled, pulled her hard hat back on, and walked toward the reactor hall where the blue light was waiting, patient and endless, for its next pellet.

Reader's Guide

The nuclear fuel chain in Factorio runs roughly as follows: uranium ore is mined from the map, then processed (typically in a furnace or assembling machine) into raw uranium. That uranium is then fed into a chemical plant alongside a secondary reagent to produce nuclear fuel pellets, with depleted uranium generated as a co-product in the same reaction. The fuel pellets are subsequently refined—again in a chemical plant—into the final nuclear fuel that powers nuclear reactors. The full upstream dependency is: uranium ore → uranium → nuclear fuel pellet (+ depleted uranium byproduct) → nuclear fuel → reactor energy. Downstream, the reactor feeds the electric network, which in turn powers every assembling machine, furnace, and chemical plant in the factory, making the chain a self-sustaining energy loop once established. The typical bottleneck is the chemical-plant stage, because both the pellet synthesis and the final fuel refinement compete for the same machine type. Players usually need two separate chemical-plant lines (one for pellet creation, one for fuel refinement) to avoid stalling. Depleted uranium itself is not a bottleneck; it is a passive byproduct that requires only a storage tank and occasional cleanup. As the factory scales, the nuclear chain replaces oil-based power almost entirely. The ratio of uranium input to reactor output is forgiving compared to oil refining, but the chemical-plant count must roughly double to keep pace with a factory that has expanded into blue-circuit and rocket-part production. Depleted uranium accumulates in tanks and is best handled with a simple pipe-to-tank setup to avoid back-pressure on the chemical line.

Did You Know?

• Depleted uranium is produced as a byproduct in the same chemical-plant reaction that creates nuclear fuel pellets, meaning you do not need a separate machine or recipe to generate it.
• The nuclear reactor in Factorio can run for an extremely long time on a single fuel pellet, making the uranium chain one of the most energy-efficient production loops in the game.
• Unlike oil, which requires a refinery, multiple fractional-distillation steps, and a boiler-steam-turbine chain, the nuclear path skips the thermal-conversion stage entirely, simplifying the power infrastructure.
• The visual design of the nuclear facility—circular, sealed, with a distinct blue glow—was a deliberate aesthetic break from the industrial rust-and-iron look of the rest of the factory, signaling a new era of production.