Documentation Index
Fetch the complete documentation index at: https://mintlify.com/hbmmods/hbm-s-nuclear-tech-git/llms.txt
Use this file to discover all available pages before exploring further.
Nuclear fuel in NTM is not a single item — it is the culmination of an entire industrial processing chain that begins with raw ore and ends with fuel rods loaded into reactors. Uranium ore must be mined, crushed, and centrifuged into yellowcake and then powder; that powder is enriched or combined with other isotopes to produce pellets; pellets are fabricated into the appropriate rod or cartridge format for your reactor type. Different reactor systems — the RBMK, PWR, Watz, and Zirnox — all use different fuel formats with different enrichment levels and thermal behaviors. Managing the back end of the fuel cycle (reprocessing spent fuel, handling radioactive waste, and breeding new fissile material) is equally important: neglecting it leads to dangerous radioactive material accumulating in your base with nowhere to go.
The Nuclear Fuel Cycle
Uranium/Thorium Ore
│
▼
Crusher / Sifter
│
▼
Centrifuge (separates isotopes, produces powders)
│
▼
Enrichment / Blending
(LEU, HEU, MOX, Thorium mixes)
│
▼
Fuel Fabrication
(RBMK rods, PWR cartridges, Watz pellets, Zirnox rods)
│
▼
Reactor Operation
(fission / breeding)
│
▼
Spent Fuel / Breeding Rod Output
│
▼
Reprocessing (BreederRecipes, centrifuge)
or Long-Term Storage
Radiation Values
Before handling any nuclear materials, understand their radiation hazard. The HazardRegistry in NTM tracks radiation emission rates for all isotopes:
| Isotope | Half-life | Decay | Radiation (Rad/s) | Hazard Level |
|---|
| Th-232 | 14,000,000,000 a | α | 0.10 | Very Low |
| U-238 | 4,500,000,000 a | α | 0.25 | Very Low |
| U-235 | 700,000,000 a | α | 1.00 | Low |
| U-233 | 160,000 a | α | 5.00 | Moderate |
| Np-237 | 2,100,000 a | α | 2.50 | Moderate |
| Pu-239 | 24,000 a | α | 5.00 | Moderate |
| Pu-240 | 6,600 a | α | 7.50 | High |
| Pu-241 | 14 a | β− | 25.00 | Very High |
| Pu-238 | 88 a | α | 10.00 | High |
| Am-241 | 432 a | α | 8.50 | High |
| Am-242 | 141 a | β− | 9.50 | High |
| Cs-137 | 30 a | β− | 20.00 | Very High |
| Co-60 | 5 a | β− | 30.00 | Very High |
| Po-210 | 138 d | α | 75.00 | Extreme |
| Xe-135 | 9 h | β− | 1,250.00 | Critical |
Xe-135 (xenon-135) has an extremely high radiation rate of 1,250 Rad/s and accumulates inside RBMK fuel channels during reactor operation. Never handle freshly removed RBMK fuel rods without a full hazmat suit and radiation-shielded storage. Spent fuel should be stored in shielded containers or RBMK Storage Columns immediately after removal.
Uranium Fuels
Uranium is the backbone of early-to-mid NTM nuclear power. Natural uranium contains ~0.7% U-235 (fissile) and ~99.3% U-238 (fertile). Enrichment increases the U-235 fraction.
RBMK Uranium Rods
PWR Fuel Cartridges
RBMK fuel rods are the primary format for the RBMK reactor. They are individual items with NBT-tracked depletion and each has a reactivity value, heat per outgoing flux, and a burn function (logarithmic, linear, exponential, etc.).| Rod ID | Description | Burn Function |
|---|
rbmk_fuel_ueu | Unenriched natural uranium | Low output |
rbmk_fuel_meu | Medium-Enriched Uranium | Logarithmic, general purpose |
rbmk_fuel_heu233 | High-Enriched U-233 | High reactivity |
rbmk_fuel_heu235 | High-Enriched U-235 | High reactivity |
rbmk_fuel_uzh | Uranium–Zirconium Hydride | Specialized |
rbmk_fuel_thmeu | Thorium + MEU hybrid | Thorium cycle |
ItemRBMKRod with configurable parameters including xGen (xenon production multiplier, default 0.5), xBurn (xenon burnup rate, default 50), meltingPoint (default 1000 °C), and diffusion (core-to-hull heat transfer rate, default 0.02). ItemPWRFuel powers the Pressurized Water Reactor. PWR fuel uses an EnumPWRFuel type to define its heat output and burn function:| Type | Heat/Flux (TU) | Function | Notes |
|---|
| MEU | 5.0 | Logarithmic | Standard enriched uranium |
| HEU-233 | 7.5 | Square-root | U-233 based |
| HEU-235 | 7.5 | Square-root | High-enriched U-235 |
| MEN (Neptunium) | 7.5 | Logarithmic | Np-237 blend |
| HEN-237 | 7.5 | Square-root | High-enriched neptunium |
| MOX | 7.5 | Logarithmic | Mixed oxide (Pu+U) |
| MEP (Plutonium) | 7.5 | Logarithmic | Pu mix |
| HEP-239 | 10.0 | Square-root | High-enriched Pu-239 |
| HEP-241 | 10.0 | Square-root | High-enriched Pu-241 |
| MEA (Americium) | 7.5 | Logarithmic | Am blend |
| HEA-242 | 10.0 | Square-root | High-enriched Am-242 |
| HES-326 / HES-327 | 12.5 | Square-root | Schrabidium exotic |
| BFB-AM-MIX | 2.5 | Square-root | Special, 250M yield |
| BFB-PU241 | 2.5 | Square-root | Special, 250M yield |
Plutonium Fuels
Plutonium is produced by irradiating U-238 in a reactor. It is more energetic than uranium but more radioactive and harder to handle.
RBMK Plutonium Rods:
rbmk_fuel_lep — Low-Enriched Plutoniumrbmk_fuel_mep — Medium-Enriched Plutoniumrbmk_fuel_hep239 — High-Enriched Pu-239 (strongest standard plutonium rod)rbmk_fuel_hep241 — High-Enriched Pu-241 (short-lived, very hot)rbmk_fuel_mox — Mixed Oxide (Pu-239 + U-238 blend)
PWR MOX (EnumPWRFuel.MOX): 7.5 TU/flux, logarithmic burn — a good mid-tier PWR fuel.
Thorium Fuels
Thorium-232 is fertile (not directly fissile) but can be transmuted to U-233 under neutron irradiation. The thorium cycle is a lower-waste alternative to the uranium-plutonium cycle.
rbmk_fuel_thmeu: RBMK rod using a Thorium + MEU blend, enabling thorium cycle operation inside the RBMK.- Breeding Rod
TH232 → THF: A Breeding Rod loaded with Th-232 absorbs neutrons and converts to thorium fluoride (THF), a step toward U-233 production (requires 500 flux).
Th-232 has an extremely low radiation level (0.10 Rad/s) — it is the safest common nuclear material to handle. However, its decay products (including Ra-226 and Ac-227) are significantly more hazardous.
Watz Isotropic Fuel (Watz Pellets)
ItemWatzPellet (formally “Watz Isotropic Fuel, Oxidized”) is a specialized pellet format for the Watz reactor system. Each EnumWatzType variant has unique color, heat emission, burn function, and temperature coefficient properties:
| Type | Max Heat | Heat/Flux | Burn Func | Notes |
|---|
| SCHRABIDIUM | 2,000 | 20.0 | Linear (1.5×) | Highest tier, exotic |
| HES | 1,750 | 20.0 | Linear (1.25×) | High-enriched Schrabidium |
| MES | 1,500 | 15.0 | Linear (1.15×) | Medium Schrabidium |
| LES | 1,250 | 15.0 | Linear (1.0×) | Low-enriched Schrabidium |
| HEN | 0 | 10.0 | Square-root | High-enriched Np |
| MEU | 0 | 10.0 | Square-root | Medium uranium |
| MEP | 0 | 15.0 | Square-root | Medium plutonium |
| LEAD | 0 | 0 | — | Absorber (negative coeff.) |
| BORON | 0 | 0 | — | Improved absorber (linear) |
| DU | 0 | 0 | — | Depleted U absorber (positive coeff.) |
| NQD / NQR | 2,000–2,500 | 20–30 | Linear | Special exotic |
mudContent parameter that tracks the rate of “mud” byproduct production per reaction flux, and a heatDiv (temperature coefficient function) that governs how the reactor self-regulates based on heat.
Zirnox Fuel Rods
ItemZirnoxRod is NTM’s Zirnox reactor fuel — a zirconium-alloy cladded rod type with NBT-tracked lifetime (life counter). Each EnumZirnoxType has a maxLife, heat output per tick, and optional breeding capability:
| Type | Max Life | Heat/t | Breeding |
|---|
| Natural Uranium Fuel | 250,000 | 30 | No |
| Uranium Fuel | 200,000 | 50 | No |
| Th-232 | 20,000 | 0 | Yes |
| Thorium Fuel | 200,000 | 40 | No |
| MOX Fuel | 165,000 | 75 | No |
| Plutonium Fuel | 175,000 | 65 | No |
| U-233 Fuel | 150,000 | 100 | No |
| U-235 Fuel | 165,000 | 85 | No |
| LES Fuel (Schrabidium) | 150,000 | 150 | No |
| Lithium | 20,000 | 0 | Yes |
| ZFB-MOX | 50,000 | 35 | No |
breeding = true (Th-232 and Lithium) generate new fissile material through neutron capture rather than directly producing heat.
Breeding Rods
ItemBreedingRod rods are inserted into RBMK irradiation channels or similar irradiators. They absorb neutron flux to convert the input isotope to an output isotope (tracked by BreederRecipes):
| Input Rod | Output Rod | Required Flux |
|---|
| Lithium | Tritium | 200 |
| Co (Cobalt) | Co-60 | 100 |
| Ra-226 | Ac-227 | 300 |
| Th-232 | THF (Th fluoride) | 500 |
| U-235 | Np-237 | 300 |
| Np-237 | Pu-238 | 200 |
| Pu-238 | Pu-239 | 1,000 |
| U-238 | RGP (Reactor-Grade Pu) | 300 |
| Uranium (natural) | RGP | 200 |
| RGP | Waste | 200 |
The Lithium → Tritium breeding route (200 flux) is the primary way to produce tritium for fusion reactor fuel. A single RBMK irradiation channel or Fusion Reactor Breeding Chamber can run multiple breeding rods simultaneously.
Depleted RTG Pellets
ItemRTGPelletDepleted represents spent radioisotope thermoelectric generator (RTG) fuel pellets. They are the waste product of RTG operation and come in the following types:
BISMUTH, MERCURY, NEPTUNIUM, LEAD, ZIRCONIUM, NICKEL
These are low-level radioactive waste items. They should be stored in shielded containers or disposed of through appropriate waste management machines, not left loose in chests.
Fuel Processing: Centrifuge
The centrifuge is the workhorse of the fuel processing chain. It separates ore chunks, coal, and raw materials into usable powders and separated isotopes. Example outputs from CentrifugeRecipes:
- Rare ore chunk → cobalt powder (×2 tiny), boron powder (×2 tiny), niobium powder (×2 tiny), zirconium nuggets (×3)
- Coal ore → coal powder (×6), gravel (×1)
Uranium ore is crushed and centrifuged to yield separated U-235 and U-238 powders, which are then blended or enriched to the desired enrichment level.
Spent Fuel and Reprocessing
Spent RBMK fuel rods, depleted PWR cartridges, and other irradiated items are highly radioactive. Plutonium-241 at 25 Rad/s and Co-60 at 30 Rad/s are among the most hazardous spent fuel components. Always wear a full radiation suit (hazmat gear) when handling spent fuel, and store it immediately in lead-lined or shielded containers. Never leave spent fuel on the ground or in open inventories near your base.
- Breeding Rods: Place spent or partially-depleted rods back into an irradiation channel to continue neutron capture chains (e.g., Np-237 → Pu-238 → Pu-239).
- Centrifuge: Some spent materials can be re-centrifuged to separate remaining fissile content.
- Long-term storage: Truly depleted waste (e.g., RGP → Waste rod) should be stored permanently in deep underground storage or disposed of via waste processing machines.
Fuel Selection Guide
| Reactor | Recommended Early Fuel | Recommended Late Fuel | Notes |
|---|
| RBMK | rbmk_fuel_ueu or rbmk_fuel_meu | rbmk_fuel_heu235, MOX, Schrabidium | Start with natural/MEU; upgrade as enrichment infrastructure grows |
| PWR | pwr_fuel_meu | HEP-239, HEA-242, HES-326 | Logarithmic fuels are stable; sqrt fuels have high burst output |
| Watz | MEU or MEP pellets | SCHRABIDIUM, NQR | Watz has unique temperature coefficient mechanics — read heatDiv values |
| Zirnox | Natural Uranium or Uranium Fuel rods | U-233, LES, Plutonium | Breeding rods (Th-232, Lithium) enable in-situ fuel generation |
| Fusion | Deuterium + Tritium | Higher-tier plasma fuels | No fuel rods — uses fluid isotopes; tritium bred via Lithium Breeding Rod |
