Uranium-235

Lore & Background

In the sprawling industrial landscape of Factorio, uranium ore deposits cling to the edges of the world where pollution has thickened the air and the ground glows faintly with residual radiation. These sparse veins of dark, dense ore are the raw material from which the most powerful fuel in the game is born. The Centrifuge is a quiet, humming machine—far less violent than a smelter or furnace. It is not explosive in the hands of the factory, but it is hungry. Slotted into an empty Nuclear Fuel Cell, it begins a slow, steady burn that will outlast any coal or oil-fired generator by an order of magnitude. The fuel cell glows with a soft, persistent warmth as it feeds the reactor core. It frees the production lines from the tyranny of oil wells and coal mines, yet it introduces a new rhythm: fuel cells degrade, reactors must be refueled, and the centrifuge must never stop turning. The nuclear chain is a living system, and the player becomes its caretaker.

In Their Own Story

The centrifuge hall was quiet at 3 a.m. by factory-time, a long corridor of white machines humming in unison, their glass fronts glowing faintly amber. Mira walked the inspection path between the rows, listening. The rhythmic whir was steady—good. A centrifuge that stuttered meant a jammed isotope feed, and a jammed feed meant a reactor going cold within the hour. She pulled a sample tray from the output chute. She dropped them into the fuel-cell loader and watched the empty cells click into place, one by one, their cores igniting with a low, warm pulse. Down the hall, the reactor array breathed. Heat exchangers hissed, steam turbines spun, and the grid held. Somewhere far below, the last oil pipeline was already being dismantled, its pipes coiled and stacked. The factory had outgrown fire. Now it ran on the slow, patient burn of enriched isotope, and Mira's only job was to make sure the centrifuges never, ever stopped.

Reader's Guide

This is carried by conveyors or inserters into the Centrifuge. This is the enrichment step and the only place the isotope is produced. Downstream: Charged Nuclear Fuel Cells are inserted into Nuclear Reactors. Reactors transfer heat to adjacent Nuclear Heat Exchangers, which produce steam. Steam Turbines convert that steam into electricity for the grid. Bottleneck: The Centrifuge is almost always the rate-limiting stage. It has a fixed processing speed per unit, so large-scale nuclear grids require many centrifuges running in parallel. Fuel-cell replacement logistics (removing spent cells, inserting fresh ones) also add a recurring bottleneck that grows with reactor count. Scaling: As the factory expands, you will need to build out centrifuge banks, dedicated fuel-cell staging areas, and automated replacement loops. The nuclear chain is modular—each reactor + heat exchanger + turbine cluster is a self-contained unit—but the shared centrifuge and fuel-cell supply must scale linearly with the number of active reactors. Plan your uranium mining, enrichment, and fueling logistics early to avoid a grid-wide blackout when the last fuel cell runs dry.

Did You Know?

• Nuclear Fuel Cells have a finite operational lifespan—once spent, they must be removed and replaced, introducing a recurring maintenance loop absent from coal or oil generation.
• Uranium ore deposits are sparse and clustered in specific high-pollution regions of the map, making early scouting and logistics planning critical for any factory aiming for nuclear power.