Nuclear Reactor

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Nuclear Reactor
Nuclear Reactor.png
ID: reactor1
Usable device for generating electrical power.
Item Slots 4 Fuel Rod slots 
Max Power Output 10000 kW 
Required Skill Electrical Engineering 55
Required Item Screwdriver.png Screwdriver
Nuclear Reactor
ID: outpostreactor
Usable device for generating electrical power.
Item Slots 4 Fuel Rod slots 
Max Power Output 20000 kW 
Required Skill Electrical Engineering 55
Required Item Screwdriver.png Screwdriver

The Nuclear Reactor is an installation. It uses fuel rods to produce power to the submarine.


The nuclear reactor's function is to generate power for other installations on the submarine. As long as the reactor is active, every other connected device on the ship will remain active as well. Power generated by the reactor is sent to other installations via wiring. Power distribution requires Junction Boxes to work, as the reactor cannot send power to other installations directly. Maintaining the power network is one of the most important aspects of a round, as the submarine cannot function without power.

The nuclear reactor undergoes nuclear fission, in which atoms are split apart, cause large amounts of energy to be released. The rate at which these reactions take place is measured by the fission rate. The resulting reaction also causes heat to be released that raises the overall temperature of the reactor. If the temperature raises past 6,000 degrees for too long, the reactor will catch on Fire. If the temperature stays over 9000 degrees for too long, it will meltdown, creating a massive radioactive explosion. It is possible to fix the submarine and reactor after a meltdown, but it is difficult due to radiation, lack of power and, often, hull breaches. Because of this, the cooling and fission rates must be adjusted to keep the temperature at a desired level - which is usually the same as the amount of power consumed by the electrical grid of the submarine.

Fuel Rods are required for the nuclear reactor to function. The reactor can hold up to four rods. They will be slowly consumed at a rate proportionate to the Fission Rate. Fuel Rods can be removed and replaced at any time.

If the reactor is in water, it will take damage over time, down to 10% condition.

Even when not in water, a reactor will slowly deteriorate over time, proportional to turbine output and fission rate. A reactor will not deteriorate below 10% condition by itself.

If the reactor reaches 0% condition and has a fuel rod in, it will instantly meltdown.


Turbine output

At maximum turbine output, the reactor has a maximum power output depending on the submarine. This can be changed in the Submarine Editor.

Turbine Output is how much electricity the reactor will output, which will need to be adapted to the ship's consumption. So if 2000kW are required and 1000kW are produced, the turbine output will need to be doubled.

The Turbine in turn works off heat. If there isn't enough heat, then the turbine can't produce the output it is set to. The turbine is merely capped by whether or not it has enough heat. It does not produce more power via excess heat. It only produces as much power as it is set to, as long as it has enough heat to sustain that level of power output.

  • Turbine Output constantly consumes heat, so suddenly increasing the turbine output without increasing fission rate will reduce the temperature of the reactor.
    • This will decrease the power output instead of increasing it, since the reactor won't keep up with the turbine.
    • Similarly, if turbine output is too low relative to fission rate a heat build-up may occur.

Therefore, Turbine Output must be balanced with heat generation by adjusting the Fission Rate.

Note: if the reactor outputs more power than is needed, junction boxes will gradually become damaged. And if load is higher than maximum output, electrical devices may flicker or stop working.

Generating heat

The Fission Rate combined with the fuel rods determines how much heat is available. It is fully linear, so doubling Fission Rate will double the heat output which will allow doubling the power generation by doubling the Turbine Output. Inserting a second rod while halving the Fission Rate will leave the heat unchanged and allow keeping the same Turbine Output and power output without consequences. Note: if rods are added and/or fission rate is increased but heat is not used by increasing the turbine output, then the reactor overheats and takes damage, eventually leading to a meltdown

  • Time before meltdown occurs can be increased via upgrades.
  • Max power output is achieved at 5000 degrees, being less than 5000 will lower output proportionally.

Note: if the fission rate is too low, there won't be enough heat and the turbine won't be able to generate the actual output that it has been set to.

Fuel rods

Different fuel rods burn hotter for the same fission rate. Maxing out 100% on the Turbine Output requires a Heat Potential of at least 100.

  • Heat Potential of all rods currently in the reactor is added together, this just means that a lower fission rate can be used to achieve the same heat.

Special Case: Only 1 Uranium Rod
The only way to get heat potential less than 100 is to use exactly 1 Fuel Rod, which has a Heat Potential of 80. Fission Rate has a maximum of 100% but it is limited by Heat Potential, so with only 80 Heat Potential Fission Rate is capped at 80%.

Due to the way heat generation works, 1 Uranium Rod can actually reach up to 85% maximum power output, however the Turbine output must be set to 85% or lower, because heat generation cannot be stably set past 80% fission.

If Turbine Output is above 85% with a single rod, the power output will drop to only 56% at 100% Turbine due to the loss in temperature.

  • In general, it is best to keep heat potential above 100 by using more rods or rods with higher heat potential; to avoid wasting overall power output.
  • It is possible to momentarily pass 80% fission, though the reactor will quickly correct this back down to 80% on the gauge.

Fuel efficiency

Fuel rods deteriorate proportionally to the fission rate and fuel consumption rate of the reactor, the lower fission rate the longer each rod lasts.

  • In the Submarine Editor, the fuel consumption rate of reactors can be changed. (Default: 0.2)
  • Fuel consumption rate can be decreased via upgrades.
  • The equation for per rod fuel consumption is (Fuel Consumption Rate * Fission) / # of rods
    • Therefore, The per rod consumption for a reactor containing 2 rods at 90% fission with the default consumption rate would be (0.2 * 0.9) / 2 = 0.06/s

The fission rate is linear, so using rods one at a time or all at once provides the same amount of runtime overall. For example, using 4 of the same type of rod just causes each rod to lose durability at 1/4th speed.

There are some other benefits to using multiple rods, mainly that changing rods is less frequent and less movement of the needle is needed for fission rate.

  • Reducing load to the reactor can decrease the fission rate and increase overall runtime.


The nuclear reactor's control panel.

Critical Heat:

  • The temperature is at or above 7742 and the reactor is on.
  • The reactor is melting down.

Critical Output:

  • The power output is more than 150% (1.5x) of the current load and the reactor is on.

Critically Low Temperature:

  • The temperature is below 2258 and the reactor is on.


  • The left gauge, labeled "Fission Rate", indicates the current fission rate of the reactor.
  • The right gauge, labeled "Turbine Output", indicates the current turbine output of the reactor.
  • Red areas show unrecommended settings.
  • Yellow areas show "ok" settings.
  • Green areas show recommended settings.

Temp Low:

  • The temperature is below 3660 and the reactor is on.


  • The temperature is at or above 6370 and the reactor is on.
  • The reactor will shortly burst into flames.

Output Low:

  • The power output is less than 90% (0.9x) of the current load.

Output High:

  • The power output is more than 110% (1.1x) of the current load.

Fuel Low:

  • The available fuel is less than the fission rate and the reactor is on.

Fuel Out:

  • The available fuel is less than 1% of the fission rate and the reactor is on.


  • The reactor is halfway past the meltdown timer and is on. OR The reactor has condition 0 and is on.


  • The reactor is powered off and the temperature is more than 0.

Temperature Graph

  • The colored squares indicate the current temperature of the reactor.
  • The bottom red notches indicate the lowest "ok" temperature for the reactor.
  • The top red notches indicate the highest "ok" temperature for the reactor.
  • A flashing red section above the top red notches indicate that the reactor is overheating, and may burst into flames or explode.

Power/Load Graph

  • "Load" indicates the current load of the connected power grid.
  • "Output" indicates the current power output of the reactor.
  • The yellow line is power output.
  • The blue line is grid load.
Example scenarios
  • There is a spike in load from captain suddenly steering the ship

Load is increased instantaneously, causing a low-power situation while the reactor increases its Fission Rate (which takes a little bit to catch up) and possibly Reaction Rate (unless there was already enough extra heat being generated).

  • There is a drop in load from unplugging oxygen generator

Load is decreased instantaneously resulting in far more power generated than required, which causes damage to the junction boxes until the Turbine Output decreases (and Fission Rate, too, to avoid excess heat).

  • More fuel rods are added to the reactor

More fuel rods without changing the Fission Rate results in dramatically increased heat, causing damage to the reactor and a possible meltdown, unless the Turbine Output is increased to consume that heat. No extra power is generated unless the Turbine Output is increased accordingly.

  • Turbine output is increased without increasing fission rate

Since heat level has not increased, the power generated won't actually go up, and might actually go down. This will be a "temp low" situation.

  • Turbine Output is decreased without decreasing fission rate

The turbine is no longer consuming the heat that is generated, so the reactor will begin to get hotter and possibly overheat and meltdown.


When a reactor is selected, a control panel opens up. The panel displays two gauges, a bar graph, and a line graph. They represent the fission rate, turbine output, temperature, and reactor load/output respectively.
In this control panel, players can manually set the fission rate and turbine output of the reactor or toggle automatic control.

Manual control

Under manual control, the Fission and Turbine are controlled manually. A player should be stationed near the reactor to adjust the fission and turbine appropriately for the ship's fluctuating power requirements.
Manual control can respond to power fluctuations faster than Automatic mode, but requires player attention. The suggested regions are affected by Electrical Engineering, which can compensate for slightly inaccurate placement.

  1. Start the reactor using the button on the top-right labelled "Power". The light next to the button should glow.
  2. Ensure automatic control is off. The light next to the switch should be off.
  3. The sliders beneath Turbine Output and Fission Rate can be drag & dropped. When hovering the mouse over one of the sliders, they can also be adjusted using the keyboard movement keys.
    • Horizontal movement (default A & D) controls the fission rate, vertical movement (default W & S) controls turbine output.

Note: In general, the fission rate should be as low in the green region as possible (to generate exactly as much heat as needed). The turbine output should be near upper part of the green (to exactly meet the load).

Automatic control

Enabling Automatic Control adjusts Fission and Turbine automatically. It reacts to changes in load slower than a human can, but requires little player attention.

  1. Start the reactor using the button on the top-right labelled "Power". The light next to the button should glow.
  2. Turn on automatic control using the switch on the top-right labelled "Automatic Control". The light next to the switch should be on.
  3. The reactor will slowly adjust Turbine Output towards the load and Fission Rate towards the middle temperature (5000).

Note: It is possible to use multiple fuel rods with regular Automatic Control, however this requires the fission to be lowered manually or shutting the reactor off before adding the extra rods. Otherwise the adjustment will be too slow and a fire will start if no preparation is done.

Connection Panel for Nuclear Reactor
Hover over pins to see their descriptions.
Connection Port.png
Connection Port.png
Connection Port.png
When it receives any signal, fission rate and turbine output are set to 0, and reactor is turned off.
Sets fission rate to a fixed percentage (0-100)
Sets turbine output to a fixed percentage (0-100)
Connection Port.png
Connection Port.png
Connection Port.png
Connection Port.png
Connection Port.png
Connection Port.png
Connection Port.png
Connection Port.png
Power output of the reactor.
Outputs the reactor's current temperature (0-10000).
Outputs a signal of 1 when reactor is high temp (>6000).
Outputs the current power level as a number (supplied power).
Outputs the current load level as a number (required power).
Outputs the cumulative Heat Potential of current fuel rods as a number (see Fuel Rods).
Outputs the Nuclear Reactor's current condition. (0-100)
Outputs the sum of the fuel rods' condition percentage. (0-100)

Wire control

Wire control adjusts Fission Rate and Turbine Output remotely through Wiring Components. Wire control overrides both Automatic and Manual controls. It can also be used to warn about overheating, meltdowns, and used to remotely shut down the reactor.
Wiring can change the Fission and Turbine much faster than Automatic, if calculated properly this can prevent overvoltage to junction boxes and other electrical devices.

  • The shutdown input can be used to remotely shutdown the reactor, unlike other inputs it will activate if any non-null signal is sent. (So sending 0 still shuts it down)
  • The reactor cannot be started remotely. However, it is possible to achieve a similar effect by setting Fission Rate and Turbine Output to 0 when you want the reactor to be "Off".

Fuel rods

Fuel Rod Type Durability Heat Potential Electrical Skill to Craft Crafting Materials Crafting Time Store Price
Fuel Rod.png Fuel Rod 100 80 25 Uranium.png Uranium

Lead.png Lead Steel Bar.png Steel Bar

10 135-150 Marks
Thorium Fuel Rod.png Thorium Fuel Rod 200 100 60 Thorium.png Thorium

Lead.png Lead Steel Bar.png Steel Bar

10 225 Marks
Fulgurium Fuel Rod.png Fulgurium Fuel Rod 150 150 40 Fulgurium Chunk.png Fulgurium Bar

Lead.png Lead Steel Bar.png Steel Bar

10 Not purchasable
Volatile Fulgurium Fuel Rod.png Volatile Fulgurium Fuel Rod 400 150 70 and Hazardous Materials Fulgurium Chunk.png Fulgurium Bar

Thorium.png Thorium Lead.png Lead Steel Bar.png Steel Bar

25 Not purchasable

Volatile Fulgurium Fuel Rods inflict 0.2 Affliction Radiation Sickness.png Radiation Sickness per second to nearby characters within 2.5 meters and 1/s within 1 meter, regardless of whether the rod is in the reactor, in a container, or in a character's inventory.
Any crew handling them or in proximity of the reactor should be equipped with radiation protective Gear.
The PUCS.png PUCS will grant immunity to Radiation Sickness, while a Hazmat Suit.png Hazmat Suit paired with any other type of Diving Suit will provide 70% resistance.


When a reactor reaches 0% condition, and if there is a fuel rod in it, it will meltdown, generating a large radioactive explosion. Fuel rods in the reactor will be completely exhausted.

Afflictions on Hit
Structure Damage
Kinetic Force
Explosion Radius (m)
Nuclear Reactor

Affliction Burn.png Burn : 200

Affliction Deep Tissue Injury.png Deep Tissue Injury : 50

Affliction Radiation Sickness.png Radiation Sickness : 50

Affliction Stun.png Stun : 5

Outpost Nuclear Reactor

Affliction Burn.png Burn : 200

Affliction Deep Tissue Injury.png Deep Tissue Injury : 80

Affliction Radiation Sickness.png Radiation Sickness : 80

Affliction Stun.png Stun : 5


Default Submarines Max Power Output

Submarine Max Output Fuel Consumption Rate
Azimuth 3,500 0.2
Barsuk 4,200 0.2
Berilia 6,500 0.3
Dugong 3,000 0.2
Herja 4,800 0.2
Humpback 2,950 0.2
Kastrull 5,000 0.3
Orca 3,500 0.3
Orca 2 3,500 0.3
R-29 5,200 0.2
Remora 5,000 0.3
Typhon 5,000 0.2
Typhon 2 5,000 0.25
Winterhalter 10,000 0.2


Submarine Weapons