A fission addon for GregTech Modern focused on **cool, adaptable features** and **heavy configurability**. It can be used standalone, but it’s primarily designed for **pack developers** who want to reshape reactor behavior, balance, and progression for their own packs. There are 3 **main reactor multiblocks**: ### **Pressurized Fission Reactor** Uses **Fission Coolers**, **Fission Moderators**, and a **Driver Fuel Rod** to produce **EU** and **waste**. * **Cooling** is provided by all installed coolers (total HU/t). * **Coolant consumption behavior is configurable**: * **Additive**: every cooler adds to the coolant draw, or * **Primary-only**: only the “primary” (highest-tier / most dominant) cooler determines coolant use. ### **High Performance Breeder Reactor** Uses **Fission Coolers**, **Fission Moderators**, **Blanket Rods (targets)**, and a **Driver Fuel Rod** to produce **stronger fuels** for future breeder cycles, plus some power. * Blanket processing supports **fluid or item inputs/outputs** (GT material IDs _or_ Forge registry IDs). * Blanket usage behavior can be made **configurable** as well (additive blankets vs primary-only), matching the coolant model style. ### **Molten Salt Reactor** Uses **MSR Liners** and **Fission Coolers** to process molten salts. * Designed to process heavier fissile materials and slowly process them into safer more useful products. * Will accumulate Xenon Poisoning over time that you will need to extract from fluid hatches. * Has a different heat model focused around flow, not heat. ## Custom UIs. All 4 base machine classes have a custom UI for your viewing pleasure! ### Base fission reactor and breeder reactor ui. ![image](https://media.forgecdn.net/attachments/description/1443603/description_abbc9ae8-472c-43c9-acba-50c7b3d9aece.png) There are even graphs to see your safety at a glance! ![image](https://media.forgecdn.net/attachments/description/1443603/description_d973f401-4dc0-45dd-9d65-36b93ccdefe5.png) ![image](https://media.forgecdn.net/attachments/description/1443603/description_282848a3-5919-45f8-9782-2f9f4b7464b9.png) And a math page! ![image](https://media.forgecdn.net/attachments/description/1443603/description_0521f732-6f05-4eac-b0ef-a94ff6de5222.png) ![image](https://media.forgecdn.net/attachments/description/1443603/description_b5cf056e-7b96-4b93-8756-754feee65b8e.png) ## Molten Salt Reactor UI. ![image](https://media.forgecdn.net/attachments/description/1443603/description_052ddabc-9bd2-42c5-9ace-15d75bf8fd17.png) ## Heat exchanger UI. ![image](https://media.forgecdn.net/attachments/description/1443603/description_13c1c469-0122-4c96-9bca-bc3b73a6f86b.png) *** ## KubeJS Content Support New **Coolers**, **Moderators**, **Fuel Rods**, and **Blanket Rods** can all be defined in **KubeJS**. Key points: * Coolers now use **pure Forge fluid registry IDs** for coolant (example: `gtceu:distilled_water`). * Coolers may optionally define an **output “hot” coolant** (example: distilled water → steam). * If the reactor **can’t output the hot variant**, it can optionally **void the output** (pack-configurable behavior), so the reactor can still run without requiring an output hatch in every build. * Usage behavior (coolant / fuel / blanket) can be driven by **config toggles** (additive vs primary-only). Below is an example of each type.

StartupEvents.registry("block", event => {

// 1. CUSTOM FISSION COOLER
event.create('aether_flow_cooler', 'phoenix_fission:fission_cooler')
.displayName('Aether-Flow Cooler')
.tier(3) // Determines explosion scaling and tier-matching logic
.coolerTemperature(1025) // Active heat dissipation capacity (HU/t)
.coolantUsagePerTick(10) // Millibuckets of coolant fluid consumed per operation tick
.requiredCoolantMaterialId('phoenixcore:frost') // Input fluid registry ID
.outputCoolantFluidId('phoenixcore:warm_frost') // Output heated fluid registry ID
.tintColor(0xFF7DE7FF) // Does nothing but nessecary, leave default
.texture('kubejs:block/fission/aether_flow_cooler') // Note: Requires a matching block and active block texture (active is appended to the end)

.maskTexture('phoenix_fission:block/fission/cooler_mask'); // Optional mask texture layer

// 2. CUSTOM FISSION FUEL ROD
event.create('high_density_driver_rod', 'phoenix_fission:fission_fuel_rod')
.displayName('High-Density Driver Rod')
.tier(3) // Controls internal multi-block priority and explosion tiers
.baseHeatProduction(50) // Core HU/t heat produced before moderator modifiers
.durationTicks(1200) // Lifetime in ticks before burning another cycle of fuel
.amountPerCycle(1) // Quantity of fuel items consumed per cycle completion
.neutronBias(1) // Interacts with nearby Breeder/Blanket rod output instability weights
.fuelKey('gtceu:uranium_235_nugget') // Input item ID (Supports tags or specific registry IDs)
.outputKey('gtceu:depleted_uranium_235_nugget') // Output waste item ID
.texture('kubejs:block/fission/high_density_driver_rod'); // Note: Requires a matching block and active block texture (active is appended to the end)

// 3. CUSTOM FISSION MODERATOR

event.create('niobium_modified_silicon_carbide_moderator', 'phoenix_fission:fission_moderator')
.displayName('Nb-SiC Moderator')
.tier(4) // Primary moderator selection hierarchy weight
.euBoost(15) // Scaling factor for increasing EU generation output
.fuelDiscount(5) // Efficiency discount: Extends fuel rod duration ticks between cycles
.texture('kubejs:block/fission/niobium_sic_moderator');

// 4. CUSTOM BREEDER / BLANKET ROD
event.create('uranium_blanket_rod', 'phoenix_fission:fission_blanket_rod')
.displayName('U-238 Blanket Rod')
.tier(2) // Priority logic tier matching
.durationTicks(2400) // Total tick lifetime per transformation cycle
.amountPerCycle(1) // Item consumption rate per cycle completion
.inputKey('gtceu:uranium_238_nugget') // Target breedable material registry entry
// Dynamic Outputs: .addOutput(RegistryKey, Weight, Instability)
.addOutput('gtceu:plutonium_nugget', 70, 1)
.addOutput('gtceu:plutonium_241_nugget', 20, 3)
.addOutput('gtceu:plutonium_238_nugget', 10, 4) // High instability means higher output if neutronBias matches
.texture('kubejs:block/fission/uranium_blanket_rod');

// 5. CUSTOM MOLTEN SALT REACTOR (MSR) LINER
event.create('advanced_msr_liner', 'phoenix_fission:msr_core_liner')
.displayName('Advanced MSR Core Liner')
.tier(3)
.fluidFlowRate(40) // Max mB/t fluid flow processing rate through the liner
.heatPerMb(15.5) // Thermal energy generation constant per millibucket processed
.inputFluidId('gtceu:enriched_naquadah_salt') // Molten salt fuel blend input
.outputFluidId('gtceu:depleted_naquadah_salt')
.texture('phoenix_fission:block/fission/liner_base'); // Also needs an active texture
});

Phoenix's Fission

Compatibility

Minecraft: Java Edition

Platforms

Supported environments

Links

Tags

Creators

Details

Equilibrium Graph.

Breeder Reactor UI.

MSR UI

Heat Exchanger UI.

Net Rate Graph.