Phoenix's Fission
by Phoenixvine
Phoenix's Fission is a Forge reactor mod for GregTech modern that lets pack developers reshape how fission reactors behave, with three main reactor multiblocks and four base machine classes.
What it does
Reactors in the mod are built from three main multiblocks and use fission coolers, fission moderators, driver fuel rods and blanket rods. Installed coolers total their heat removal in HU/t, and coolant consumption is configurable, with only the primary, highest-tier cooler setting the coolant use. Blanket processing accepts fluid and item inputs and outputs using GT material IDs and Forge registry IDs, and additive blankets versus primary-only matching can be set in config. Heavier fissile materials are slower to process but yield safer and more useful products.
The reactor builds up Xenon Poisoning over time, and extract fluid hatches are needed to deal with it. Component types can be defined in KubeJS, with an optional mask texture layer for their models. The mod can be used standalone or as a balancing tool in custom packs, and it is open source under the GNU Lesser General Public License v3.0 only.
Key features
Configurable coolant use
Coolant consumption and the heat removal of installed coolers can be set in config, with only the highest-tier cooler determining coolant use.
Blanket processing
Blankets take fluid and item inputs and outputs, with additive or primary-only matching chosen in config.
Xenon Poisoning
The reactor builds up Xenon Poisoning over time, which is countered through extract fluid hatches.
KubeJS-defined components
Coolers, moderators, fuel rods and blanket rods are defined through KubeJS, with an optional mask texture layer on their models.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
How it compares
Dea's Fission is a Forge fission addon for 1.20.1 under All rights reserved, and it is not open source, while Phoenix's Fission is open source under the GNU Lesser General Public License v3.0 only. Mekanism Fission Meltdown Rework is server-side only and open source under the MIT License for 1.20.1 – 1.20.6, so players can join without installing it. GregTech Modern Utilities is open source under the GNU Lesser General Public License v3.0 or later and is a client and server mod for 1.20.1.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Phoenix's Fission | Forge | 1.20.1 | Client and server | 2026-07-11 |
| Dea's Fission | Forge | 1.20.1 | Client and server | 2025-11-03 |
| Mekanism Fission Meltdown Rework | Forge | 1.20.1 – 1.20.6 | Server-side only | 2026-03-06 |
| GregTech Modern Utilities | Forge | 1.20.1 | Client and server | 2026-08-25 |
Questions
Does Phoenix's Fission require GregTech Modern?
Does the server need Phoenix's Fission?
Can a pack developer add custom reactor parts?
In the catalog
Phoenix's Fission is one of 8,499 Technology mods on ModsFinder, and one of 4,122 Technology mods for Forge. 34,764 mods support Minecraft 1.20.1.
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What the author says
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. Uses Fission Coolers, Fission Moderators, and a Driver Fuel…
Official listing
- Modrinth page
- modrinth.com/mod/phoenixs-fission
- Owner
- Phoenixvine
- Published
- 2026-07-11
- Updated on Modrinth
- 2026-07-11
- Facts verified
- 2026-10-15