Small Reactors
Tech mods are the backbone of many long-term Minecraft worlds, and Small Reactors is a bold attempt to build a fresh industrial progression from the ground up. Originally created as an experimental tech add-on for Minecraft 1.17, it is still marked as highly work in progress, yet it is fully functional and playable from the first ore you mine to the moment your first lightning bolt powers a factory. If you enjoy mods that reward planning, ore processing chains and smart energy management, this one deserves a spot in your modpack.
Supported Versions and Loaders
Small Reactors targets Minecraft 1.17 and is built for the Fabric loader, making it a natural fit for players who prefer lightweight, fast-loading mod setups. Because the project is still in development, expect the version list to grow over time. Always check that your loader and game version match the build you plan to use, since mixing versions is the fastest way to break a world.
Ores and World Generation
The foundation of the mod is a set of custom ores, each with its own spawn rules and purpose. Learning where they appear saves hours of blind mining.
- Silver spawns like gold and feeds alloys, power components and one of the starter generators.
- Zinc appears in uncommon but larger veins in higher regions, used for alloys and upgrade kits.
- Bismuth generates uncommonly in lower regions and supports alloys, radiation shielding and RF containment.
- Apatite is rare around sea level in large veins, supplying phosphate fertilizer and fluorine.
- Brimstone forms large common veins across the Nether and becomes sulfuric acid for processing apatite.
- Spodumene is rare around diamond level and refines into lithium through an advanced chain.
- Bauxite appears in uncommon large veins up high and, with cryolite from crushed redstone ore, becomes aluminium.
- Rock Salt spawns in large clumps similar to andesite and produces brine for sodium hydroxide and chlorine.
Generators and Power Production
Power generation is where Small Reactors really differentiates itself. Instead of one universal generator, you get a ladder of options that scale with your infrastructure.
- Stirling Engine burns furnace fuel for 20RF/t and intelligently avoids wasting fuel while its buffer has room.
- Steam Engine converts steam into 40RF/t.
- Gas Engine burns fluid fuels for 80RF/t and can be upgraded with steam for 50% more efficiency and power.
- Fuel Cell Engine burns high purity fuels slowly at 20RF/t but starts at +50% efficiency, can reach +125% with the gas engine upgrade, and doubles output when restricted to hydrogen.
- Lightning Engine captures strikes from a connected lightning rod, producing 1,000,000RF per bolt at 160RF/t.
That lightning engine is the highlight for many players. It discharges fully even when there is nowhere for the energy to go, and it cannot accept a new bolt until the previous charge is spent, so timing your storms matters.
RF Storage and Machines
Energy management is handled by two tiers of energy cells. The Basic Energy Cell stores 1,000,000RF and transfers 320RF/t, retains its charge when broken, and offers configurable sides plus a balance mode that equalizes power between connected cells. The Advanced Energy Cell jumps to 16,000,000RF and 5,120RF/t, giving you room for serious automation.
Machines cover the full production chain. The Redstone Furnace smelts twice as fast at equal efficiency and upgrades into a smoker or blast furnace. The Alloy Smelter produces the mod's alloys, while the Crusher processes ore blocks at fortune 3 equivalent, upgrades to fortune 4, and turns raw ores into dusts at 1.25x with secondary outputs. The Water Source fills nearby tanks, and the Geothermal Well slowly solidifies underground lava across a 4x4 chunk area to generate steam, though it refuses to work in the Nether.
Chemistry fans get plenty of depth too. The Chemical Reactor gassifies coal, wood and kelp into syngas and can reform it into hydrogen, with ingredient order mattering: carbon first, oxygen second, steam third. The Pressurized Absorption Swinger pulls oxygen from the air, the Biogas Reactor turns any compostable junk into biogas, the Electrolyzer splits fluids into two or three outputs at up to 320RF/t, and the Magma Crucible melts solids for aluminium and lithium refining. A Wrench rotates engines and configures energy cell sides, while the Gas Vent releases unwanted gases, so be careful with waste chlorine.
If you would rather skip manual mod folder juggling, the foxygame.net launcher installs Small Reactors in a single click and keeps your add-ons updated automatically, which is a real convenience for a mod that receives frequent changes.
Getting Started
To download Small Reactors, grab the build that matches Minecraft 1.17 and your Fabric setup. If you are unsure how to install it, drop the mod file into your mods folder alongside Fabric API, launch the game once to generate configs, then start hunting silver and zinc. From there, build a Stirling Engine, expand into steam, and work toward the lightning engine for late-game power.
Final Thoughts
Small Reactors for Minecraft is rough around the edges and openly unfinished, but that is part of its charm. The ore variety, layered generator progression and chemistry-driven machine chains give tech players a genuinely new puzzle to solve. If you want a mod that grows with your world and rewards careful engineering, this add-on is well worth the download.
===ARTICLE===