Neutronics

A reactor is a heat-economics engine you build into a station or rented room. Load fissile fuel, a real neutron-flux simulation runs, and the heat it captures is turned into Drive Cells — the warp fuel that moves capital fleets. Run one well and it out-produces every other generator; run one badly and it melts down. No reactor is meltdown-proof.

In this section

• Building a Reactor: the block set, the sealed shielding box, the coolant run to the turbine, and commissioning the Core Console.
• Fuel & Isotopes: mining and enriching uranium, the U-235 → spent → U-238 → Pu-239 chain, and the β safety margin each fuel carries.
• Neutronics Physics: criticality (k-eff), Doppler self-limiting, the demand-follower servo, and the xenon poison transient.
• Power & Operation: throttle as control rods, the cruise / push / redline bands, SCRAM, and how heat becomes Drive Cells.
• Nuclear Waste: fission products and Xe-135, why everything you withdraw consolidates into one Nuclear Waste item.
• Neutronics Roster: every reactor block, fuel, and byproduct at a glance.
• Troubleshooting & FAQ: won't commission, climbing heat, a dead k gauge, xenon dead-time, over-bred plutonium, and meltdowns.

The Starter Kit

Buy one Reactor Starter Kit (reactor.starter_kit) and right-click to unpack. It drops the exact tested T1 layout — the known-good build that makes ~1,000 Drive Cells/hr at 45% throttle, walk-away-safe — into your inventory, plus a starter fuel supply:

The Plating, Viewports, Hatches, and Door wrap the working guts in a simple hollow box — the shielding gate only cares that no working block faces outside air, so open interior space is fine. The full build walkthrough is on Building a Reactor. Reactors run only on a station or a rented room, never on a ship.

The big loop

1. Build and commission. Cluster the guts — fuel touching exchangers, exchangers on a coolant run that reaches the turbine, a vent beside each fuel block — then wrap the whole thing in a hollow Plating box with a few Viewports to watch it. Set the Core Console in one wall and right-click it to commission. See Building a Reactor.
2. Enrich fuel. Mine Raw Uranium Ore from deep planet veins and enrich it at an Enrichment Centrifuge (a dedicated machine, not the ore refinery). One run splits the ore into Uranium-235 rods plus Uranium-238 tailings. See Fuel & Isotopes.
3. Load and run. Right-click a Fuel Assembly holding a rod to load it, then right-click the Core Console to raise the throttle. The throttle is the control rods. Hold it in the cruise band and Doppler feedback self-limits the core, so it's safe to leave; the push band adds output for more burn and more heat, attended only; redline melts. See Power & Operation.
4. Collect Drive Cells. The heat the core sheds through the exchangers spins the turbine, and that becomes Drive Cells — your warp fuel and the whole point of the machine.
5. Breed premium fuel. A burnt-out rod ejects Uranium-238 directly — a spent rod IS depleted uranium — and you already have U-238 from the enrichment tailings. Load it as fertile fuel into a breeder — a tight-packed 2×2×2 fuel cube with the moderator pulled back — and it breeds to Plutonium-239, which makes 1.5× the Drive Cells of U-235. Breeding is a harvest-timing skill: pull the Pu-239 before it walks on to poisonous Pu-240. See Fuel & Isotopes.

Running accrues fission products and xenon poison. You see them live in the Fuel Port, but withdrawing any of them consolidates the lot into one terminal Nuclear Waste item — see Nuclear Waste.

See also

• Stations: rent a door to run a reactor without owning a station
• Mining: where Raw Uranium Ore and other feedstock come from
• Fabrication: building reactor blocks and enriching fuel
• Crafting wiki: full bootstrap tree for every item