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Games / Subnautica 2 / Thermal Reactor Module

1 Why Thermal Energy Means Never Charging Again

🌋

Thermal Reactor Module

★★★★☆ — Infinite Lava Power
Mid Game

The Thermal Reactor Module converts heat from thermal vents into unlimited power for your Tadpole. Park near any lava geyser or thermal vent and your Power Cell recharges automatically — no sun needed, no resources consumed, completely free energy forever.

★ What This Means for You

This is endgame power management. Combined with the Depth Module MK1, you can explore the volcanic depths indefinitely. The Thermal Reactor turns the most dangerous environments into your personal charging stations. No more rationing power on long expeditions.

2 Crafting Recipe

Final Craft

Thermal Reactor Fragment x2 @ Scanner = Blueprint
Magnetite x2 + Kyanite x1 + System Chip x1 + Titanium Ingot x1 @ Vehicle Modification Station = Thermal Reactor Module

Complete Materials List

MaterialQtySourceLocationRate
Thermal Reactor Fragment2Scan fragmentsLava Castle (~1200m) / Thermal Vents (~200-400m)100% (scan)
Magnetite2Magnetite outcropsJellyshroom Caves (~250m) / Mountains (~300m)100% (node)
Kyanite1Kyanite outcropsLava Zones ONLY (~900-1400m)100% (node)
System Chip1Craft1 Gold + 1 Copper Wire @ Fabricator
Titanium Ingot1Craft10 Titanium @ Fabricator

3 Materials & Locations

Each material with exact location, drop rate, and farming tips.

⚒ Thermal Reactor Fragment

Source: Scan fragments
Location: Lava Castle (~1200m) / Thermal Vents (~200-400m)
Drop Rate: 100% (scan)

⚒ Magnetite

Source: Magnetite outcrops
Location: Jellyshroom Caves (~250m) / Mountains (~300m)
Drop Rate: 100% (node)

⚒ Kyanite

Source: Kyanite outcrops
Location: Lava Zones ONLY (~900-1400m)
Drop Rate: 100% (node)

⚒ System Chip

Source: Craft
Location: 1 Gold + 1 Copper Wire @ Fabricator
Drop Rate:

⚒ Titanium Ingot

Source: Craft
Location: 10 Titanium @ Fabricator
Drop Rate:

4 Optimal Collection Route

Follow this order to minimize backtracking and maximize efficiency.

① Scan Fragments (Deep/Dangerous)

Fragment 1: Lava Castle (~1200m) — INACTIVE LAVA ZONE, extremely dangerous. Requires Prawn Suit with Depth Module MK2 and thermal protection.
Fragment 2: Large Thermal Vents (~200-400m) — safer alternative, found in Grassy Plateaus borders and Blood Kelp edges.

② Get Kyanite (The Real Challenge)

Kyanite ONLY spawns in Lava Zones at 900-1400m depth. You need:
- Prawn Suit with Depth Module MK2 (900m+)
- Or Cyclops with Shield Generator
- Thermal protection (Prawn Suit has built-in)
Look for blue crystal outcrops on cave walls in the Inactive Lava Zone.

③ Gather Other Materials

Magnetite: Jellyshroom Caves or Mountains (see Engine Efficiency guide)
Titanium Ingot: 10 Titanium from Limestone Outcrops
System Chip: Gold + Copper Wire

④ Install

Craft at Vehicle Modification Station → Install on Tadpole
INFINITE THERMAL POWER

5 ⚠ Gotcha Tips — Don't Waste Your Time

Read this BEFORE you start.

⚠ Kyanite requires Prawn Suit + Depth MK2

You cannot reach Kyanite depths (900m+) without a Prawn Suit upgraded with Depth Module MK2. This is a major prerequisite chain. Plan accordingly.

⚠ Lava Zones have Sea Dragon Leviathans

The Inactive Lava Zone is patrolled by Sea Dragon Leviathans — the most dangerous predators in the game. Stay near walls, move quietly, and have a Shield Module ready.

⚠ Thermal Vents damage unshielded vehicles

Direct contact with thermal vent heat damages your Tadpole. Park at the edge of the heat radius, not directly on top of the vent.

⚠ This is ENDGAME — don't rush it

The Thermal Reactor requires Prawn Suit, Depth MK2, and Lava Zone access. This is one of the last upgrades you should pursue. Get Depth Module MK1, Engine Efficiency, and Photovoltaic Charger first.

6 🎁 Free Benefits — Loot Along the Way

Don't leave empty-handed.

🎁 Lava Zone exploration

While hunting Kyanite: The Lava Zones contain precursor technology, data terminals with critical story information, and unique resources like Crystalline Sulfur and Nickel Ore.

🎁 Prawn Suit preparation

While building up to this: You'll need to build a Prawn Suit anyway, which gives you drilling capability for large resource deposits and combat options against Leviathans.

🎁 Thermal vent areas (shallow)

While scanning the safer fragment at 200-400m vents: These areas have unique flora, precursor scans, and sometimes hidden supply caches from other survivors.