Extreme Reactors

Overview

Extreme Reactors is a power generation mod built around two multiblock machines: the Reactor and the Turbine. Reactors consume Yellorium or Blutonium fuel to produce either Redstone Flux (RF) directly through passive cooling, or Steam through active cooling that feeds into Turbines for significantly higher power output. The mod is a port of the classic Big Reactors mod from Minecraft 1.7.10, updated for modern Minecraft versions.

The core gameplay loop involves mining Yellorite Ore, smelting it into Yellorium Ingots, building a Reactor, and then scaling up your power infrastructure as your energy needs grow. Both Reactors and Turbines are highly configurable multiblock structures that can range from compact 5x5x5 starter builds up to enormous 32x32x48 Reactors and 16x16x32 Turbines. The mod also supports ComputerCraft and OpenComputers integration, allowing you to automate and monitor your power systems with Lua programs.

You can browse all 110 items and blocks this mod adds using the Items tab above, and check the Recipes tab for the full list of 50 crafting recipes.

Reactor Mechanics

Understanding how Reactors work under the hood is essential for building efficient designs. The Reactor simulates a simplified fission process where fuel rods emit radiation that interacts with surrounding moderator materials. The radiation generates heat, which is then converted into either RF (passive cooling) or Steam (active cooling).

Fuel and Waste

Reactors accept two fuel types: Yellorium and Blutonium. Both produce Cyanite as waste. Each Fuel Rod column holds 4,000 mB of fuel (4 ingots worth), and the total fuel capacity scales with the number of Fuel Rod columns. Waste accumulates in the same Fuel Rods and must be extracted through an Access Port set to Output mode. Cyanite isn't useless though: 8 Cyanite Ingots can be crafted into 1 Blutonium Ingot, creating a fuel recycling loop that stretches your Yellorium supply significantly.

Control Rods

Each Fuel Rod column requires a Control Rod on top. Control Rods have an insertion level from 0% (fully withdrawn, maximum output) to 100% (fully inserted, minimal output). Increasing insertion reduces radiation intensity, which lowers both power output and fuel consumption. This lets you throttle your Reactor to match your actual power needs rather than burning fuel at maximum rate constantly. You can set all Control Rod levels at once through the Reactor Controller GUI or individually through each Control Rod's GUI.

Heat and Temperature

Reactors track two temperatures: Fuel Temperature and Casing Temperature. Radiation from fuel rods generates heat in the fuel, which transfers to the reactor casing. In passively cooled Reactors, casing heat dissipates into RF at 50% efficiency. The Reactor stores up to 10,000,000 RF internally. Higher temperatures don't necessarily mean more power; what matters is the rate of heat transfer. A well-moderated Reactor runs cooler while producing more useful energy per unit of fuel consumed.

Interior Moderator Blocks

The blocks you place inside your Reactor's interior dramatically affect its performance. Moderator blocks sit between and around Fuel Rods and influence four key properties: Absorption (how much radiation the block captures), Heat Efficiency (how effectively absorbed radiation converts to heat), Moderation (how much the block slows neutrons, increasing their chance to cause further fission), and Heat Conductivity (how quickly heat transfers through the block to the casing). The ideal moderator depends on whether you're running passive or active cooling.

For passively cooled Reactors producing direct RF, you want high moderation and heat efficiency to maximize power per fuel unit. Graphite Blocks are the best vanilla option with 2.0 moderation and 0.5 heat efficiency. For actively cooled Reactors producing Steam, Diamond Blocks (0.85 heat efficiency, 1.5 moderation, 3.0 conductivity) or Enderium Blocks (0.88 heat efficiency, 1.6 moderation, 3.0 conductivity) are top-tier choices. If you have access to Thermal Expansion, Gelid Cryotheum fluid placed inside the Reactor offers the best moderation value in the game at 6.0, with 0.95 heat efficiency.

Passive vs. Active Cooling

Reactors operate in one of two modes depending on their components. A passively cooled Reactor has Power Taps but no Coolant Ports, and converts heat directly into RF at 50% efficiency with a 20% heat transfer rate. This is simpler to build and works well for early to mid-game power needs. A passively cooled Reactor can store up to 10,000,000 RF internally.

An actively cooled Reactor has Coolant Ports instead of (or in addition to) Power Taps. Water is pumped in through an inlet Coolant Port, absorbs heat from the reactor casing, and vaporizes into Steam at a rate of 4 RF worth of heat per mB of Water. The Steam is then piped out through an outlet Coolant Port to a Turbine for power generation. Active cooling is more complex to set up but produces substantially more power per unit of fuel, especially when paired with optimized Turbines.

Building Turbines

Turbines are the second multiblock machine in Extreme Reactors. They consume Steam from actively cooled Reactors and convert it into RF through a spinning rotor mechanism. A Turbine is built as a hollow rectangular structure using Turbine Housing blocks, similar to how Reactors use Reactor Casing. The minimum size is 5x5x4 and the maximum is 16x16x32.

Turbine Components

Every Turbine requires one Turbine Controller, at least one Turbine Power Tap (RF or Tesla), at least one Turbine Fluid Port for steam input, and exactly one Turbine Rotor Bearing. The Fluid Port can be toggled between inlet (for Steam) and outlet (for exhausted Water) by right-clicking with a Wrench. You'll need at least two Fluid Ports, one for each direction, to maintain flow.

The Rotor Assembly

Inside the Turbine, you build a rotor from Turbine Rotor Shaft blocks and Turbine Rotor Blade blocks. The shaft runs from the Rotor Bearing inward along one axis, and blades extend outward from the shaft perpendicular to it. Each blade can process 25 mB of Steam per tick by default, so more blades means higher throughput. The maximum Steam intake for any Turbine is 2,000 mB per tick, meaning you need at most 80 blades to handle maximum flow. Each shaft and blade block adds 10 to the rotor mass, which affects inertia and friction.

Coil Blocks

The Turbine generates power through electromagnetic induction. Metal blocks placed adjacent to the Rotor Shaft (but not on the blade end) act as inductor coils. The coil material determines three properties: Efficiency (power multiplier), Bonus (additional power scaling), and Extraction Rate (how quickly energy is pulled from the rotor). Better coil materials mean more RF per mB of Steam consumed. The inductor can be engaged or disengaged through the Turbine Controller GUI, letting the rotor spin up to speed before you start extracting power.

Materials and Fuel Cycle

Yellorium

Yellorium is the primary fuel for Reactors. It comes from smelting Yellorite Ore, which spawns below Y=32 in the Overworld. If the config option registerYelloriteSmeltToUranium is enabled (default: true), Yellorite Ore will smelt into whatever item is registered as ingotUranium in the ore dictionary, providing cross-mod compatibility. Similarly, if registerYelloriumAsUranium is enabled, all Extreme Reactors recipes will accept Uranium Ingots in place of Yellorium.

Cyanite and Blutonium

Cyanite is the waste byproduct of reactor fission. It accumulates in the Fuel Rods and must be extracted periodically through an Access Port set to Output. Cyanite can be recycled: craft 8 Cyanite Ingots together to produce 1 Blutonium Ingot. Blutonium functions identically to Yellorium as reactor fuel and also produces Cyanite waste, creating a closed fuel loop. Alternatively, Cyanite can be crafted from Yellorium Ingots and Sand if the config option enableCyaniteFromYelloriumRecipe is enabled.

Graphite and Steel

Graphite Ingots are obtained by smelting Coal or Charcoal. They're used extensively in crafting Reactor Casing and Turbine Housing, and Graphite Blocks serve as excellent reactor moderators. Steel Ingots are used in various component recipes. Both materials can be stored as compact 3x3 storage blocks.

Ludicrite

Ludicrite is the high-end material in Extreme Reactors. Ludicrite Blocks require Blutonium Ingots and either a Nether Star or Blaze Rods to craft, making them expensive but powerful. As a Turbine coil material, Ludicrite offers the best efficiency (3.5x) and extraction rate (3.5x) in the mod. Ludicrite crafting requires resources from both the Nether (Blaze Rods) and boss fights (Nether Star), placing it firmly in late-game progression.

Ores and World Generation

Extreme Reactors generates three ores across three dimensions. All world generation settings are configurable and can be disabled entirely.

Redstone and Computer Control

Redstone Port

The Reactor Redstone Port allows basic automation without mods like ComputerCraft. It can be configured to output a Redstone signal based on reactor conditions (temperature thresholds, fuel levels, energy stored) or accept input signals to activate/deactivate the reactor or set control rod levels. The Redstone Port emits particle effects when outputting a signal, making it easy to see its state at a glance. Redstone updates occur every 20 ticks (1 second) by default.

ComputerCraft and OpenComputers

For advanced automation, both Reactors and Turbines support Computer Ports compatible with ComputerCraft and OpenComputers. The Reactor Computer Port exposes methods to query fuel temperature, casing temperature, energy stored (up to 10,000,000 RF), fuel and waste amounts, coolant levels, energy produced last tick, and fuel consumed last tick. You can also set control rod levels, activate/deactivate the reactor, and eject waste or fuel programmatically.

The Turbine Computer Port provides methods to read rotor speed (RPM), energy production, fluid flow rates, blade count, blade efficiency, rotor mass, and inductor engagement status. Control methods let you set the maximum fluid flow rate, switch vent modes (DoNotVent, VentOverflow, VentAll), and engage or disengage the inductor coil. This enables sophisticated control loops that match Steam production to Turbine demand automatically.

Configuration Options

Extreme Reactors has an extensive configuration file organized into seven categories. Server administrators should pay special attention to the size limits and power multipliers, as these directly affect game balance in multiplayer environments.

The Reactor section controls maxReactorSize (default 32, X/Z dimensions) and maxReactorHeight (default 48). Reducing these values prevents players from building oversized Reactors that might cause server performance issues. The reactorPowerProductionMultiplier (default 1.0) stacks with the global powerProductionMultiplier to scale output.

The Turbine section sets maxTurbineSize (default 16) and maxTurbineHeight (default 32). The turbineFluidPerBladeMultiplier adjusts how much Steam each blade processes (base 25 mB). The drag multipliers (aero, coil, mass, friction) let you fine-tune how efficiently Turbines convert kinetic energy to RF.

The Recipes section contains several toggles. Set requireObsidianGlass to true to require hardened or reinforced Glass from other mods instead of regular Glass. If registerCharcoalForSmelting or registerCoalForSmelting conflict with other mods, disable them and enable the alternative crafting recipes (registerGraphiteCharcoalCraftingRecipes or registerGraphiteCoalCraftingRecipes) that use Gravel instead.

World generation can be toggled per-ore and per-dimension using the dimensionWhitelist (which can also act as a blacklist by setting useBlacklist to true). The fuelUsageMultiplier globally scales how quickly Reactors consume fuel.

Progression Guide

Early Game: Your First Passive Reactor

Start by mining Yellorite below Y=32 and smelting Coal into Graphite Ingots. Build a 5x5x5 passively cooled Reactor with a single Fuel Rod column in the center, surrounded by Graphite Blocks as moderators. This compact design produces a steady stream of RF with good fuel efficiency. Connect a Power Tap to your energy storage or cable network and you'll have reliable power for early automation.

Mid Game: Scaling Up and Active Cooling

As your power demands grow, expand your Reactor or build larger ones with more Fuel Rod columns. Once you have a reliable Water supply (Aqueous Accumulator, pump, or similar), transition to active cooling by adding Coolant Ports. Pipe Water in and Steam out to your first Turbine. A properly built Turbine with Gold or Silver coils will produce significantly more RF per mB of fuel consumed than a passive Reactor of the same size.

Late Game: Optimized Turbine Arrays

The endgame of Extreme Reactors involves building large Reactors feeding multiple Turbines. Craft Ludicrite Blocks (requiring Blutonium and Nether Stars) for the best coil material at 3.5x efficiency and 3.5x extraction rate. Optimize your Reactor interior with Diamond Blocks or, if available, Gelid Cryotheum for maximum Steam output per fuel unit. Set up ComputerCraft controllers to manage rod insertion and Turbine flow rates automatically, matching production to demand and minimizing waste.