Reactor

The reactor is a milestone found at 1133-1134km (W2-101 - W2-102km). The Buff Lab is found at 1135km (W2-103km). This is where you finally learn why not to sell isotopes. Its shortcut is "R".

The reactor is used to generate Nuclear Energy that is stored in batteries and used for creating bombardments. The bombardments are burned to create late moon isotopes Einsteinium and Fermium.

The Reactor is a puzzle/management minigame into itself, and a quite entertaining one at that. As such, this page has been designed to keep as spoiler-free as possible until the "Strategy" heading. 8th classical guide (careful, as that guide is not spoiler-free) is also linked from there.

For the really helpful Reactor Planner made by Adversarius#2964 click here.

Historical note

• Before v0.40, the Reactor was located at 1313km, W2-301 and W2-302. The Buff Lab was found at W2-303.
• When the Reactor was first added all the components were known from the first level.

Basic concepts

Preparation

Once you're near the Reactor, stock up on Oil. It will be your second-most-needed resource.

As now the reactor is unlocked just before unlocking Magnesium, at the start there is really not much to do. Without Magnesium you cannot craft batteries, and without batteries you cannot store Energy, and thus you cannot use buffs or upgrade the reactor. You can, however, start crafting the other components. Patience. Magnesium used to be the most limiting resource even when the Reactor was unlocked 200 km deeper.

Components

There are six types of components:

• Rods: Generate energy and heat
• Fans: Cool/Dissipate heat.
• Batteries: Store the energy into Nuclear Energy
• Heat Ducts: Connect Rods to Fans and other Heat Ducts
• Bombardments: Consume energy to create new isotopes, generate heat
• Buffs: Enhance the effects of the Rods/Fans/Batteries they are placed next to (cannot buff buffs). Unlocked at Reactor lv. 3

You craft components and put them on a "layout". The components you can craft and the size of your possible layouts will depend on your Reactor level. Your objectives are:

• First, enough cooling. If not enough cooling, the Reactor will stop.
• Second, generate enough energy
• Third, use up that energy.

There are nuances to how fans and ducts connect to rods so if you don't want to read the full strategy it's best to ask questions in the Discord General chat channel if you get stuck.

Shift + Click

The most useful shortcut here is Shift+Click.

• If used on the Inventory (left column), it places that component into the first available slot of the reactor (left to right, up to down).
• If used on the Reactor, it places that component back into the Inventory. There are subtleties to this, which are explained below, at the start of the Strategy section. The spoiler-free version is: Better not to use it on Fuel Rods OR Bombardments unless you're very sure they've completely burned (finished timer).

Reactor and Buff Lab Level Cost

(Very minor spoilers: If you want to discover all by yourself, stop here. The only surprises are the sizes and shapes of the Reactor at each level)

Reactor and buff lab Level costs

level	Reactor cost	grid space	Buff lab cost	Buff Discount
level 1	free	(9 slots)	free	0%
level 2	25 Bm 20k power 10 e1	(15 slots)	50 Bm 400,000 power	10%
level 3	50 Bm 200,000 power 100 e1	(25 slots)	100 Bm 3,000,000 power	20%
level 4	100 Bm 750,000 power 50 e2	(45 slots)	250 Bm 5,000,000 power	25%
level 5	500 Bm 1,500,000 power 30 e3	(81 slots)	400 Bm 8,000,000 power	30%

Reactor Components

(Mild spoilers: If you want to discover by yourself all components and when are they unlocked, stop here. Otherwise, it's nothing the game won't eventually tell you, right on the user interface).

this is what it would look like if you have all the components

Component Name/ List Priority	Makes/Does	Type	Heat	Cost to make	Unlocks in
Fan	-12 heat	Fan	-12 heat (-1 Fan worth of Heat)	2.5 million aluminum 1,000 oil	Reactor 1
Highly Enriched Uranium Fuel Rod	4,500 u2 750 u3 2,500 Pu1 500 Pu2 36,000 energy (10 per sec) 1 hour	Fuel Rod	24 heat (2 fans worth of heat)	8,000 u1 3,000 u2 500 u3	Reactor 1
Dual Highly Enriched Uranium Fuel Rod	9,300 u2 1,550 u3 5,050 Pu1 1,010 Pu2 108,000 energy (30 per sec) 1 hour	Fuel Rod	66 heat (5.5 fans worth of heat)	16,000 u1 6,000 u2 1,000 u3	Reactor 2
Quad Highly Enriched Uranium Fuel Rod	19,200 u2 3,200 u3 10,200 Pu1 2,040 Pu2 324000 energy (90 per sec) 1 hour	Fuel Rod	180 heat (15 fans worth of heat)	32,000 u1 12,000 u2 2,000 u3	Reactor 3
Enriched Uranium Fuel Rod	23,000u2 17,250 Pu1 144000 energy (10 per sec) 4 hours	Fuel Rod	18 heat (1.5 fans worth of heat)	72,000 u1 11,500 u2	Reactor 1
Dual Enriched Uranium Fuel Rod	23,000u2 17,250 Pu1 432,000 energy (30 per sec) 4 hours	Fuel Rod	48 heat (4 fans worth of heat)	144,000 u1 23,000 u2	Reactor 2
Quad Enriched Uranium Fuel Rod	23,000u2 17,250 Pu1 1,296,000 energy (90 per sec) 4 hours	Fuel Rod	126 heat (10.5 fans worth of heat)	288,000 u1 46,000 u2	Reactor 3
Mixed Oxide Fuel Rod	2,000 u3 1,500 Pu13 288,000 energy (8 per sec) 10 hours	Fuel Rod	21 heat (1.75 fans worth of heat)	22,800 u2 2,880 u3 32,700 Po1 3,270 Po2	Reactor 1
Dual Mixed Oxide Fuel Rod	4,040 u3 3,030 Pu3 864,000 energy (24 per sec) 10 hours	Fuel Rod	54 heat (4.5 fans worth of heat)	57,600 u2 5,760 u3 65,400 Po1 6,540 Po2	Reactor 2
Quad Mixed Oxide Fuel Rod	8,210 u3 6,160 Pu 2,592,000 energy (72 per sec) 10 hours	Fuel Rod	144 heat (12 fans worth of heat)	115,200 u2 11,520 u3 130,800 Po1 13,080 Po2	Reactor 3
Small Battery	stores 5,000 energy	Battery	0 heat (0 fans worht of heat)	2 million magnesium	Reactor 1
Large Battery	stores 50,000 energy	Battery	0 heat (0 fans worth of heat)	2 small batterys 10 million magnesium 25,000 power	Reactor 2
Extra Large Battery	stores 250,000 energy	Battery	0 heat (0 fans worth of heat)	2 large batterys 50 million magnesium 400,000 power	Reactor 3
Heat Duct	transfers heat	duct	0 heat (0 fans worth of heat)	15 million iron 2,000 power	Reactor 1
Copper Buff	buffs the top and bottom by 55%	Buff	0 heat (0 fans worth of heat)	50 milllion copper 200,000 power	Reactor 3
Platinum Buff	buffs the left side and bottom by 55%	Buff	0 heat (0 fans worth of heat)	50 milllion platinium 500,000 power	Reactor 4
Silver Buff	buffs the top and right side by 55%	Buff	0 heat (0 fans worth of heat)	50 milllion silver 500,000 power	Reactor 4
Gold Buff	buffs the corners by 30%	Buff	0 heat (0 fans worth of heat)	50 million gold 1.5 million power	Reactor 5
Californium Bombardment 1	10 e1 -288,000 energy (-10 per sec)	Bombardment	24 heat (2 fans worth of heat)	15,000 power 1 million califormium 1,000 h1	Reactor 1
Californium Bombardment 2	10 e2 -864,000 energy (-30 per sec)	Bombardment	72 heat (6 fans worth of heat)	150,000 power 1 million califormium 1,000 h2	Reactor 2
Californium Bombardment 3	10 e3 -2,592,000 energy (-90 per sec)	Bombardment	216 heat (18 fans worth of heat)	1.5 milllion power 1,000,000 californium 1,000 h3	Reactor 3
Pu/Po Fuel Rod	2,000 Po3 921600 energy (16 per sec)	Fuel Rod	36 heat (3 fans worth of heat)	4,000 Pu3 72,500 Po1 7,250 Po2	Reactor 1
Dual Pu/Po Fuel Rod	4,040 Po3 2764800 energy (48 per sec) 16 hours	Fuel Rod	96 heat (8 fans worth of heat)	8,000 Pu3 145,000 Po1 14,500 Po2	Reactor 2
Quad Pu/Po Fuel Rod	8,160 Po3 8294400 energy (144 per sec) 16 hours	Fuel Rod	264 heat (22 fans worth of heat)	16,000 Pu3 290,000 Po1 29,000 Po2	Reactor 3
Polonium RTG Fuel Rod	1036800 energy (6 per sec) 48 hours	Fuel Rod	15 heat (1.25 fans worth of heat)	2,500 Po3	Reactor 1
Einsteinium Bombardment 1	1 F1 -1,152,000 energy (-20 per sec) 16 hours	Bombardment	30 heat (2.5 fans worth of heat)	1,000,000 power 1 million n1 10 e1	Reactor 5
Einsteinium Bombardment 2	1 F2 -3,456,000 energy (-60 per sec) 16 hours	Bombardment	90 heat (7.5 fans worth of heat)	3 million power 1 million n2 10 e2	Reactor 5
Einsteinium Bombardment 3	1 F3 -10368000 energy (-180 per sec) 16 hours	Bombardment	270 heat (22.5 fans worth of heat)	9 million power 1 million n3 10 e3	Reactor 5

Strategy

Full spoilers ahead. You've been warned. You can also check 8th's guide

Shorhands / notation

We'll be using these shorthands in discussion, and in layouts.

There are five types of Fuel Rods. The color names are also used in the Discord and the Guide.

• HE (red): Highly Enriched Uranium Fuel Rod
• E (green): Enriched Uranium Fuel Rod
• MO (purple): Mixed Oxide Fuel Rod
• PP (gray): Pu/Po Fuel Rod (gray)
• RTG (RTG): Polonium RTG Fuel Rod

The first four have a Dual and a Quad version, so Dual Highly Enriched will be DHE and Quad Pu/Po will be QPP in this notation.

There are also six types of Bombardments, three Californium Bombardments (generate Einsteinium) and three Einsteinium Bombardments (generate Fermium). Annotated, CB1, CB2, CB3, EB1, EB2, EB3

Batteries are annotated as "B", Heat Ducts as "HD", Copper Buffs as "CB", Silver Buffs as "SB", Platinum Buffs as "PB" and Gold Buffs as "GB"

General mechanics / Burn cascade

This has interesting similarities to real life, like how some nuclear fuels can be used to craft others, and how RTG are used for long-term electricity generation. See Nuclear Fuel and RTG on Wikipedia, for starters. Though the game mechanics are, of course, highly stylized.

Each type of rod will take some isotopes to craft, and give some isotopes as a "decay reward", provided you burn it in full (which you should). Decay rewards more than offset some of the isotopes used on creation, so the rods are "net negative" in some isotopes and "net positive" in others. When we say "use up/consume" here, we'll mean "net negative, after full burn".

• Red Rods/HE use up U-1, generate U-2, U-3, Pu-1, Pu-2
• Green Rods/E use up U-1, generate U-2, Pu-1
• Purple Rods/MO use U-2, U-3, Pu-1, Pu-2, generate Pu-3
• Grey Rods/PP use up Pu-3, Po-1, Po-2, generate Po-3
• RTG use up Po-3, generate nothing.

At the same time, Red Rods/HE have very short burn time (1h), with 4h for green rods/E, 10h for Purple/MO, 16h for Grey/PP, and 48h for RTG.

Isotope burn cycle

Red -> Purple -> Grey -> RTG. Note the absence of Green.

This is because, for each step (single/dual/quad), Green Rods produce the same energy (with less heat), than the corresponding Red Rod, and they last for 4h instead of 1h, so they're better for both babysitting (less rod replacement) and layout (less fans) reasons. However, they use up, each hour, on net, more than double U-1 than the Red Rods (specifically, 225% as much), without producing the corresponding doubled decay rewards (for Pu-1 it's +72%, and for U-2 it's +90% for the basic Green, and down to +66% for the Quad Green, owing to higher "double/quad" bonus in decay rewards for the Red Rods). Plus, Green Rods do not produce U-3 or Pu-2, both needed for the Mixed Oxide (Purple) Rods. And Purple Rods are the only ones producing Pu-3, needed for the Dual Pu-Po (Grey) rods, which in turn is needed by the RTG.

So, in short, if you burn Green for its advantages over Red, you will end up short in resources for Purple and Grey. So you should burn Red, always, unless time management makes this impractical.

Shift + Click Subtleties

• For Fans, Batteries, Heat Ducts and Buffs, there is no problem (other than probably stopping the Reactor) with moving them from the Inventory to the Reactor and vice versa.
• Spent (empty) Fuel Rods automatically collect its decay rewards. Be careful: Decayed fuel rods still serve as connections and removing them can stop your reactor. This applies especially when you are expecting to fill your batteries once one or more bombardments end.
• Full Fuel Rods (haven't started burning, either because you put them into the Reactor when it was stopped, or because putting them in caused the Reactor to stop), can be recovered freely.
• Half-spent Fuel Rods are another matter. You can't recover partially-spent Fuel Rods (trying to recover them would delete them instead). The game puts up a confirmation message if you click or shift-click a partially spent Rod.
• Bombardments: There is not a confirmation message for half-done Bombardments (as you recover them, they count as a Full Fuel Rod), so you can make the mistake of recovering a partially-used Bombardment. This has the effect of losing all of its progress (all the energy spent is wasted), although you can place it again in the Reactor. All in all, the only thing you lose is time. Be careful around them.

He is for Es

After blueprints levels 24, all Helium is used for is Einsteinium. DON'T SELL IT!!! The problem will be He-3. It always is. See Helium for details.

N is for Fm

• After blueprints for level 26, all Nitrogen is used for Fermium.
• DO NOT SELL NITROGEN EVER!!!
• NITROGEN IS THE LIMITING FACTOR FOR FERMIUM, NOT HELIUM!!!

Layout tips and tricks

• Generally, a layout is something you get to incrementally, instead of designing it from scratch (at least, from level 3)
• You can always substitute a Duct for a Fuel Rod, in a layout.
• Try your heat model with a Californium Bombardment, instead of a fuel rod. If it works, you can recover it (there's no commitment)
• Design first for heat, then for other things.
• Design a workable prototype first, then substitute components with Buffs, using the +55% twice trick to slowly increase the amounts.
• Buffs on Fuel Rods help with getting more energy from them, faster, useful sometimes with the long-time RTG, or when waiting to empty reactor

Notifications

• If Reactor is generating energy and the rods finish burning, the Reactor will stop (but only when the last fuel rod stops burning), and you will get a notification in news. If it is consuming energy for Bombardments, the Reactor will stop when it doesn't have any energy (and thus, notification). However, it there are batteries and bombardments, the energy will be consumed (and no notification will be sent) until all energy is consumed, even if the rods themselves burn (another way of looking at it, Bombardments are rods too, so until they are consumed, not all rods are burned, thus no notification). So, in short, if you are counting on notifications to change your rods (for example, to maintain your buffs), you cannot do Bombardments at the same time. Or, if you do Bombardments, you have to manually check rod's expiration (either on the Reactor, or having an eye on the energy meter).

Reactor component progression

• At Reactor Level 2, you'll be able to craft Californium Bombardment 2, Large Battery (50k energy each), and Dual versions of all rods except RTG.
• At Reactor Level 3, you'll unlock Californium Bombardment 2, the Quad versions of the Rods, and the Extra Large Battery (250k energy each).
• At Reactor Level 4, you'll unlock Platinum Buff and Silver Buff.
• At Reactor Level 5, you'll unlock Gold Buff and Einsteinium Bombardments 1, 2, and 3.

Reaching Level 4 is quite quick if you don't sell isotopes, because you'll be able to power through a lot of burning with timelapses. You may be able to reach it around depth 1350. However, Level 5 requires Einsteinium 3, which requires Helium 3, which is very, very rare, and only becomes practical to obtain (in the amounts needed for this) around depth 1465, when you'll be mining promethium. Thus you will reach Reactor Level 5 around depth 1500 (or more).

Getting to Level 2

This is the starter level. At first you'll only be able to craft Fans, Heat Ducts, Small Batteries (5k energy each), the 5 basic Fuel Rods and Californium Bombardment 1. You start with 1 Highly Enriched Uranium fuel rod, 2 Fans and 1 Small Battery.

Your mission is to get 20K energy and 10 Einsteinium-1 for the next level (also make sure you have 25 building materials).

Getting to Level 3

This time, you'll need 200K energy, so save up on Magnesium! You'll also need 100 Einsteinium-1. The 50 building materials shouldn't be a problem at this point, as long as you didn't squander it all on other upgrades.

Getting to Level 4

This time, you're gonna need 750K energy, so don't sell Magnesium. Also, the faster you get energy the better, so don't sell Aluminum either. You'll also need even more energy to make the 50 Einsteinium-2 required for the upgrade. Again, the building materials (150 this time) shouldn't be a problem (or at most just a little bit of a problem) by now.

Getting to Level 5

You'll need 1.5M Energy, SO YOU ABSOLUTELY CANNOT SELL ISOTOPES!!!!! Then, there's still the 30 Einsteinium-3 that is also required, which is another reason to not sell your isotopes. The building materials (500) will be a slightly bigger problem this time.