Nuclear Power Plant – Guide

The Nuclear Power Plant (Atomkraftwerk) is a nuclear power station with a closed water loop. The reactor turns feedwater into main steam, the steam turbine turns that into about 1 MW of power, and the cooling tower releases the waste heat to the outside air. At the control room desk you watch and control the whole plant. On top of that there is a fuel rod factory, a nuclear waste bunker, a reprocessing plant, three measuring devices and radiation protection gear.

The plant is not a harmless generator. Spent fuel rods are highly radioactive, the dose adds up, and if cooling fails, the core can melt. Several warning levels, each with its own sound, give you time to act before that.

All structures have their own 3D models with displays, LEDs, buttons and gauges. Labels, displays and device names appear in German or English, depending on the game language. All structures and radiation sources are fireproof, on Venus too.

Since 1.1.0 there is a large plant with the large reactor (9 rods) and the 1.5 MW steam turbine, a radiation shield gate with airlock and lockdown, shielded containers for moving fuel rods and radioactive uranium ore, see New in 1.1.0.

As everywhere in the game, power figures are shown in W, meaning energy per tick (0.5 s).

Overview#

Part	Job	Key data	Size
Reactor (Boiling Water)	makes main steam	6 fuel rods, up to 3 MW heat, steam at 280 °C, own use up to 20 kW	1.5 × 1.5 m, 3 m high, fits on one frame
Steam Turbine 1 MW	steam in, power and condensate out	35% of the steam energy becomes power	3.5 × 1.5 m, 2 m high
Cooling Tower	cools the turbine's cooling water	up to 2.5 MW of waste heat, 5 kW power	3.5 × 3.5 m, 8 m high, stands on 2 × 2 frames
Control Room Desk	shows and controls the plant	three displays and an alarm list, 300 W	1.5 × 1 m
Fuel Rod Factory	makes fuel rods	20 uranium ore + 5 steel per rod, 60 s, 5 kW	1.5 × 1 m
Nuclear Waste Bunker	stores spent rods and barrels	12 slots, 99.99% shielding, 50 W	1.5 × 1 m, 1.72 m high
Reprocessing Plant	turns 3 spent rods into one new rod	120 s, 20 kW, plus one waste barrel	1.5 × 1 m, 1.55 m high
Radiation Monitor	measures, shows the strongest sources, warns	alarm limit 0.5 mSv/h, 20 W	on the wall, 3 cells wide
Radiation Detector	small detector without a display	LED, beep, 5 W	on wall or ceiling, 1 cell
Geiger Counter	hand-held device	clicks according to the dose rate	in the hand or the tool belt
Radiation Suit and Radiation Helmet	protect against radiation	95% together	suit and helmet slot
Large Reactor (9 rods)	makes main steam, since 1.1.0	9 fuel rods, up to 4.5 MW heat, own use up to 30 kW	5 × 5 cells, 3.7 m high
Steam Turbine 1.5 MW	like the 1 MW turbine, since 1.1.0	1.5 MW power, 2.8 MW waste heat – two cooling towers	9 × 3 cells, 2 m high
Radiation Shield Gate	airtight sliding gate with airlock, since 1.1.0	99.9% shielding, lockdown, emergency open, 150 W	2 m wall face
Transport Cask	carries 9 fuel rods shielded, since 1.1.0	99.99% shielding, pull it or put it on the rover	floor device
Fuel Rod Carrier	carries 3 fuel rods, since 1.1.0	99.9% shielding, fits through chutes	item

There are also the items Fuel Rod (Uranium), Spent Fuel Rod, Fuel Rod (decayed) and Nuclear Waste Barrel.

Requirements#

• Stationeers 0.2.6428, BepInEx 5.4.23.5, StationeersLaunchPad 1.0, see Installation
• Mod in the active mod pack
• In multiplayer: the server and all players
• For the cooling tower an outside atmosphere of at least 10 kPa, full output from 80 kPa. The air must be colder than the cooling water.
• For full output a power network made of Extreme Cable or Power Cable+. Game cables limit the turbine, see Cable protection.

Building and recipes#

Part	Machine	Time	Cost
Kit (Reactor)	Autolathe, tier 2	300 s	120 steel, 20 Inconel, 15 Hastelloy, 10 gold, 20 silicon, 10 electrum
Kit (Steam Turbine 1 MW)	Autolathe, tier 2	240 s	80 steel, 60 copper, 20 invar, 15 electrum, 10 Astroloy
Kit (Fuel Rod Factory)	Autolathe, tier 2	180 s	50 steel, 10 invar, 10 constantan, 10 electrum, 5 Hastelloy
Kit (Nuclear Waste Bunker)	Autolathe, tier 2	240 s	100 steel, 120 lead, 40 iron, 30 silicon, 5 gold
Kit (Reprocessing Plant)	Autolathe, tier 2	300 s	80 steel, 40 lead, 15 Stellite, 10 Hastelloy, 10 electrum, 10 gold
Kit (Cooling Tower)	Hydraulic Pipe Bender, tier 2	240 s	100 steel, 80 iron, 60 silicon, 10 constantan
Kit (Control Room Desk)	Electronics Printer, tier 2	120 s	20 steel, 15 gold, 20 silicon, 15 copper, 10 electrum, 10 solder
Kit (Radiation Monitor)	Electronics Printer, tier 1	60 s	5 steel, 10 copper, 5 gold, 5 silicon, 2 lead, 5 solder
Kit (Radiation Detector)	Electronics Printer, tier 1	15 s	2 copper, 1 gold, 2 silicon, 1 iron, 1 lead
Geiger Counter	Electronics Printer, tier 1	30 s	4 copper, 2 gold, 2 silicon, 2 iron, 2 solder
Radiation Suit	Autolathe or Tool Manufactory	30 s	5 iron, 5 copper, 20 lead
Radiation Helmet	Autolathe or Tool Manufactory	20 s	2 gold, 2 copper, 8 lead, 2 silicon
Kit (Large Reactor)	Autolathe, tier 2	420 s	180 steel, 30 Inconel, 25 Hastelloy, 15 gold, 30 silicon, 15 electrum
Kit (Steam Turbine 1.5 MW)	Autolathe, tier 2	330 s	120 steel, 90 copper, 30 invar, 20 electrum, 15 Astroloy
Kit (Radiation Shield Gate)	Autolathe, tier 2	120 s	60 steel, 80 lead, 20 iron, 5 copper, 2 gold, 2 silicon
Kit (Transport Cask)	Autolathe, tier 2	90 s	40 steel, 100 lead, 10 iron
Fuel Rod Carrier	Autolathe, tier 1	30 s	5 steel, 20 lead

The costs are in GameData/akw.xml in the mod folder.

Some parts have no printer recipe:

• Fuel Rod (Uranium): only from the fuel rod factory or the reprocessing plant.
• Nuclear Waste Barrel: only from the reprocessing plant.
• Fuel Rod (decayed): made from spent rods in the nuclear waste bunker. The game's recycler turns it into 3 steel.

The loop#

The plant has two separate water loops.

1. Feed loop: reactor → main steam (280 °C, gas pipe) → turbine → condensate (40 °C, liquid pipe) → back into the reactor. The loop is closed: every mol of steam comes back as condensate. Water is only lost when the relief valve vents.
2. Cooling loop: turbine (cooling water out, warm) → cooling tower (warm water in) → cooling tower (cold water out) → turbine (cooling water in). A small part evaporates in the tower, about 60 L of water per hour at full power.

A good third of the reactor's heat becomes power. The rest goes through the turbine's condenser into the cooling water and from the cooling tower into the outside air. In the simulator, half an hour at full power gave 10.286 GJ of heat = 3.600 GJ of power + 6.686 GJ through the tower.

Full power in numbers#

Quantity	Value at 1 MW of power
Reactor thermal power	2.86 MW (simulator, steady state)
Core temperature	586 K
Control rods	4% inserted
Main steam	113 mol per tick, 280 °C
Drum pressure in AUTO	1250 kPa
Condensate	40 °C
Cooling water through the condenser	about 2600 mol per tick, 10 K warmer
Waste heat into the cooling tower	1.86 MW
Evaporation in the tower	0.46 mol per tick, about 60 L per hour

Why only 1666 kPa?#

The steam is at 280 °C. At that temperature the vapor pressure of water in the game is 1811 kPa. Any more pressure in the pipe and the steam condenses. That is why the pressure limit sits at 92% of it, i.e. 1666 kPa. Above that the relief valve opens. AUTO control keeps the drum at 75% of the limit, which is 1250 kPa.

Steam from the drum#

A gas pipe section only holds 10 L in the game. At full power the turbine needs 113 mol of steam per tick; at 1666 kPa that would take a good 300 L of pipe. So the turbine draws any missing steam straight from the reactor's steam drum (4000 L), as long as both are on the same steam pipe network. A short pipe is enough. A closed valve in between separates reactor and turbine. Mass and energy are conserved.

Setup#

Connections#

All connections are at floor level. The rings are coloured: steam white, feedwater and condensate blue, cold cooling water cyan, warm cooling water orange, power red, data green.

Device	Side	Connections
Reactor	back	main steam (gas pipe only), power, feedwater (liquid pipe only)
Reactor	front	data
Turbine	left (+X)	main steam (gas pipe only)
Turbine	back	condensate, cooling water in, cooling water out (all liquid pipe only)
Turbine	right (−X)	power output
Turbine	front	data
Cooling tower	back	warm water in, power, cold water out (water liquid pipe only)
Cooling tower	front	data
Control room desk, bunker	back	power, data
Fuel rod factory, reprocessing plant	back	power, data; plus chute in on the left (+X, 0.5 m high) and chute out on the right (−X)
Radiation monitor, radiation detector	top	power and data in one cable

The wrong pipe can't be built onto these connections, just like with Steam Power. The hint then says "gas pipes only" or "liquid pipes only".

Step by step#

1. Put the cooling tower outdoors. It stands on 2 × 2 frames and needs outside air.
2. Place the turbine and the reactor. The reactor fits on one frame.
3. Main steam: gas pipe from the reactor (back) to the turbine (+X). An insulated pipe is recommended; in an uninsulated pipe the steam condenses quickly.
4. Feedwater: liquid pipe from the turbine's condensate connection to the reactor's feedwater connection. Fill it with water.
5. Cooling loop: cooling water out (turbine) → warm water in (tower), cold water out (tower) → cooling water in (turbine). Fill it with water.
6. Power: the turbine's power output goes onto an Extreme Cable network. Reactor, cooling tower and control room desk need power too.
7. Data: put the control room desk and all plant parts on one data network. The desk finds everything through it.
8. Fuel rods: open the fuel hatch, put six fuel rods into the channels, close the hatch.
9. Switch the main switches of reactor, turbine, cooling tower and control room desk ON, then press AUTO on the reactor or the control room desk.

In the simulator a cold plant in AUTO took a good 6.5 minutes to reach 1 MW: the core starts at 30% power until it reaches steam temperature (316 s), then it goes quickly (0.5 MW after 338 s, 1 MW after 392 s).

How much water?#

The feed loop should hold clearly more water than the reactor evaporates in one tick (113 mol at full power). The simulator uses a 200 L feedwater pipe filled to 75% (8333 mol) and a cooling loop of 2 × 300 L filled to 70%. One liquid pipe section holds 20 L, liquid water takes 0.018 L per mol. akw testanlage fills the feedwater pipe to 70% and the cooling water inlet to 80%.

You have to top up the cooling loop; at full power it loses about 60 L per hour. Make-up water goes into the warm water pipe between turbine and tower. The cooling tower's display and IC10 show how long the water will last.

Reactor#

How it works#

• Control rods: the position tells you how far the control rods are inserted. 100% = off, 0% = full power. They move at most 5% per second.
• Power: with the control rods fully withdrawn each fuel rod gives 0.5 MW of heat, so six rods give 3 MW. Output follows the rods with about 10 s of inertia.
• Decay heat: after shutdown 7% of the power remains, a good 1% after 10 minutes. Cooling has to keep running. In the simulator: 6.5% after 5 s, 3.6% after 1 min, 1.1% after 10 min, 0.2% after 1 h.
• Cooling: the feed pump evaporates up to 200 mol of feedwater per tick; full power needs about 113. At full power the core is about 35 K hotter than the steam.
• Own use: up to 20 kW with the feed pump at full, the controls alone take 10% of that. No power, no pump; no pump, no cooling. With the main switch OFF the pump keeps running for residual cooling as long as the core is above 50 °C or decay heat remains.
• Burnup: one fuel rod stores 14.4 GJ, that is 4 hours at 0.5 MW. When it is empty, it turns into a Spent Fuel Rod in its channel.
• The core loses a little heat to the air at the reactor.

Steam drum and relief valve#

The reactor has a built-in steam drum of 4000 L. From there the steam flows into the main steam pipe. If it can't get away, the pressure rises. Above the pressure limit (1666 kPa) the relief valve vents to the air on top. The reactor never bursts, but it loses water from the feed loop. At most 10 mol per tick go into the air cell above the reactor; the rest counts as carried away.

AUTO and MANUAL#

• AUTO keeps the drum pressure at the setpoint (1250 kPa) and so follows the turbine. If the turbine takes more steam, the reactor powers up; if it takes less, it powers down.
• When starting from cold, AUTO limits the power to 30% until the core reaches steam temperature.
• Above the pre-warning AUTO runs at most 80% of the current power. Without feedwater it does not power up.
• MANUAL: you set the control rods yourself with INSERT and WITHDRAW in steps of 5%. Both buttons switch AUTO off.
• AUTO can't be switched on while a scram is active or the fuel hatch is open.

Controls#

Control	Effect
Main switch	ON/OFF. OFF triggers a scram (without the scram tone), residual cooling keeps running. ON resets the scram if the core is below 650 K.
INSERT / WITHDRAW	control rod setpoint 5% further in or out, switches to MANUAL. WITHDRAW does not work during a scram, with the hatch open or the main switch OFF.
AUTO	AUTO control on or off. LEDs AUTO (green) and MAN (yellow).
E-STOP	big red mushroom button: scram, all control rods in at once
FUEL HATCH	opens and closes the fuel hatch
PAGE < / >	flips through the four display pages

The reactor also has three gauges (core temperature, pressure, power), a segment display of the control rod position and a beacon: flashing yellow at pre-warning, red from alarm. From alarm a real red warning light flashes as well.

Fuel hatch and fuel rods#

• The fuel hatch only opens when the control rods are fully inserted and fission power is below 2%. So shut down first, then open.
• Opening it switches AUTO off and sets the setpoint to 100%. The six channels can only be reached with the hatch open.
• Careful: with the hatch open the core radiates strongly. The FUEL RODS display page shows how much beforehand: "radiation open". More under Radiation.
• After a meltdown the hatch is jammed.

Display#

Page	Title	Content
1	REACTOR	thermal power in W and %, core, rods, AUTO or MANUAL, steam in mol/s, warning level with time left, the two most important warnings
2	CORE	core temperature with change in K/s, the limits (pre-warning, alarm, SCRAM or HARDCORE), level and time to the next, fission power and decay heat, core damage
3	FUEL RODS	burnup of each rod in % (X = spent), control rods actual and setpoint, possible power, fuel hatch with "radiation open", radiation outside at 1 m, heat in MWh
4	COOLING	feedwater in mol and °C, pump in mol/s with "empty in", drum pressure and setpoint, main steam pipe and limit, vented, power

LEDs#

LED	Meaning
RUN	green: switched on and powered; yellow: switched on without power
CRITICAL	blue: the chain reaction is running (fission power above 1%)
WARNING	yellow: core between 650 and 750 K
ALARM	flashing red: core at 750 K or more
SCRAM	red: scram active; flashes until acknowledged
FEEDWATER	green: enough; orange: low; flashing red: empty or no pipe
STEAM PRESS.	green: normal; orange: high; flashing red: relief valve venting
POWER	green: powered; red: no power
DATA	green: data cable connected

Steam Turbine 1 MW#

How it works#

• Each mol of steam releases c · (T steam − T condenser) + 8000 J, using the game's values. 35% of that becomes power, the rest goes through the condenser into the cooling water.
• Full power (1 MW) needs 113 mol of steam per tick and about 2600 mol of cooling water per tick, which warms up by 10 K.
• The turbine supplies on demand: it offers what steam, cooling water and the condensate pipe allow, at most up to its limit (plus 2%). It pays with steam for exactly what the network took.
• All condensate (40 °C) goes into the condensate pipe back to the reactor. Water that has collected in the main steam pipe is drained along with it.

Condenser and trip#

• The cooling water pump moves up to 4000 mol per tick from "cooling water in" to "cooling water out" and aims for a 10 K rise.
• The condenser is at least 40 °C and 3 K warmer than the outgoing cooling water. The warmer the condenser, the less power.
• From 60 °C in the condenser there is a warning.
• Trip from 90 °C (after 2 s) or when the cooling water is missing while steam comes in: the turbine stops. Turbine, reactor and control room show the reason – condenser too hot, no cooling water, or manual/IC10. Reset it with the RESET button or ACK on the control room desk as soon as the condenser is below 60 °C and cooling water arrives. Pressing too early queues the restart: the turbine then starts again by itself as soon as possible (since 1.0.2).

Bypass#

If the pressure in the main steam pipe or the drum rises above 85% of the pressure limit, the turbine dumps steam straight into the condenser without making power, up to the full rated steam flow. That way the plant survives a load rejection without the relief valve opening. In the simulator: load drop from 1 MW to 0, bypass up to 226 mol/s, drum at most 1452 kPa, no venting.

Cable protection#

The turbine never offers more than 95% of the weakest cable or fuse in its network, minus what other generators in the same network are offering. Several turbines in one network share the remainder.

Weakest part in the network	carries	Turbine supplies at most
Cable	5 kW	4.75 kW
Heavy cable	100 kW	95 kW
Super heavy cable	500 kW	475 kW
Extreme Cable	10 MW (default)	1 MW, the full output
Network made only of Power Cable+	unlimited	1 MW
Fuse	its trip limit	95% of that

A single game cable in the 1 MW network limits the whole turbine. Separate consumers on thin cables with a transformer.

Controls#

Control	Effect
Main switch	ON/OFF
MODE	AUTO (supplies on demand) or MANUAL
- and +	power limit in steps of 10%, switches to MANUAL
RESET	resets the trip once the condenser is cool and cooling water is present; pressed too early, the restart is queued; lit during a trip
PAGE < / >	flips through the four display pages

Gauges for output, condenser and speed; the shaft visibly turns.

Page	Title	Content
1	STEAM TURBINE	output and limit, possible output, speed, governor, state (RUNNING, READY, TRIPPED, OFF), warnings
2	STEAM	main steam in kPa and °C, use, bypass, condensate, efficiency
3	CONDENSER	temperature and pressure, cooling water in and out, flow and stock, waste heat, trip limit
4	STATISTICS	MWh generated, operating hours, demand, cable limit

LED	Meaning
RUN	green: running; yellow: switched on, standing still
STEAM	green: steam coming in or reactor on the steam pipe; red: no steam pipe
CONDENSER	green: normal; orange: above 60 °C; red: above 90 °C
COOLANT	blue: flowing; green: ready; flashing red: missing or pipe missing
BYPASS	yellow: bypass open
CABLE	orange: output limited by the cable limit
TRIP	flashing red
AUTO / MAN	governor
DATA	green: data cable connected

Cooling Tower#

• Pumps warm water from the inlet through the tower to the cold water outlet, up to 5000 mol per tick. Without power it runs at half pump flow.
• Heat rejection: up to 2.5 MW, 120 kW per kelvin the water is warmer than the outside air.
• Air pressure: below 10 kPa it does not cool, up to 80 kPa the output rises linearly (shown as "draught").
• Evaporation: 0.2% of the rejected heat evaporates water, about 60 L per hour at full power.
• The heat goes into the air above the crown. Outdoors the planet air evens it out. In a room it gets very hot; the tower warns you then.
• If the outside air is warmer than the water, it does not cool. So it won't work on Vulcan or Venus.
• While running, white steam plumes rise from the crown: the more heat, the more plume.
• Controls: main switch, PAGE < / >, a gauge for the cooling output.

Page	Title	Content
1	COOLING TOWER	heat rejected and possible, warm water in and cold water out, outside air, state (COOLING, READY, OFF), warnings
2	WATER	flow, evaporation in mol/s and L/h, water in the loop and how long it lasts, total evaporated
3	OUTSIDE AIR	temperature, pressure and draught in %, total heat in MWh, operating hours, power

LED	Meaning
RUN	green: switched on and powered; yellow: without power
COOLING	blue: rejecting heat
WATER	green: water in the loop; orange: evaporating, running low soon; flashing red: almost empty
AIR	green: full draught; orange: air pressure below 80 kPa; red: below 10 kPa
FAULT	orange: notice; flashing red: fault
DATA	green: data cable connected

Control Room Desk#

A desk with three large displays (reactor, turbine, cooling tower) and an alarm list. The desk finds all plant parts through its data network. If there are several reactors, turbines or towers, the displays show the first one with "1/n" in the title. The buttons act on all of them.

Buttons#

Button	Effect
INSERT / WITHDRAW	control rods of all reactors by 5%
AUTO	AUTO control on or off: the reactor holds the steam pressure, the turbine follows demand
SET MW - / +	limits the turbines in steps of 0.1 MW; 0 = on demand
SCRAM	scram of all reactors
ACK	silences the horn. With no alarm left open it also resets scram and turbine trip. Flashes while there is something to acknowledge.
VIEW < / >	changes the view
Main switch	ON/OFF

LEDs: RUN, REACTOR, TURBINE and TOWER (in the colour of their highest warning), WARNING, ALARM, DATA, AUTO and MAN. Plus a flashing beacon: yellow at pre-warning, red from alarm.

Views#

View	Reactor display	Turbine display	Cooling tower display
1 Overview	output, core with limits, rods actual/setpoint, feedwater, drum pressure	output and limit, steam, condenser, cooling water, state	water in and out, heat rejected, evaporation in L/h, outside air, state
2 Details	burnup per rod, fission, decay heat, burn time, core damage	efficiency, bypass, waste heat, cable limit, demand	flow, draught, loop water and how long it lasts, power
3 Statistics	heat in MWh, operating hours, vented, own use, scram limit	MWh generated, operating hours, power and heat of all plants	heat in MWh, evaporated, operating hours
4 Radiation & disposal	radiation monitors, reactor (outside or open hatch), radiation detectors, contaminated zones	nuclear waste bunkers	reprocessing plants

The alarm list shows the three most severe messages of all plant parts on the data network, each with the time to the next level, for example "scram in ~45 s". Without any message it reads "No faults". The desk uses 300 W.

Fuel Rod Factory#

• Makes fuel rods from uranium ore and steel ingots: 20 uranium ore + 5 steel per rod, 60 s, 5 kW. That means Ingot (Steel), not steel sheets. Up to 1.0.1 the factory ejected steel ingots as foreign items, since 1.0.2 it accepts them.
• Ore and steel arrive by the chute on the left (+X, at 0.5 m height) or by hand into the hopper. The store holds 500 uranium ore and 200 steel.
• Finished rods go into the output tray or onto the chute on the right (−X). Anything else is passed through.
• Controls: main switch, START/STOP, PAGE < / >, a progress bar with 10 segments.
• Display pages: FUEL ROD FACTORY (store, progress, produced, state) and RECIPE.
• States: PRODUCING, WAITING FOR MATERIAL, OUTPUT BLOCKED, FOREIGN ITEM - passed through, STOP, OFF.
• LEDs: RUN, WORKING, URANIUM and STEEL (green = enough for one rod, orange = too little), OUTPUT (blocked), FAULT, DATA.

New in 1.1.0: large plant, radiation shield gate, transport, uranium ore#

Version 1.1.0 adds a large expansion stage next to the existing machines, a radiation shield gate with airlock and lockdown, two shielded containers for fuel rods and radioactive uranium ore. Old saves load unchanged.

Large reactor and steam turbine 1.5 MW#

	Reactor	Large reactor	Steam turbine 1 MW	Steam turbine 1.5 MW
Size	3 × 3 cells, 3 m	5 × 5 cells, 3.7 m (two frames high)	7 × 3 cells, 2 m	9 × 3 cells, 2 m
Fuel rods	6	9	–	–
Output	3 MW heat	4.5 MW heat	1 MW power	1.5 MW power
Feed pump / steam	200 mol per tick	300 mol per tick	~113 mol steam per tick	~170 mol steam per tick
Own use	up to 20 kW	up to 30 kW	–	–
Waste heat / cooling water	–	–	1.9 MW, pump 4000 mol	2.8 MW, pump 6000 mol
Display	4 pages	6 pages of 4 lines	4 pages	5 pages of 4 lines
Kit (Autolathe, tier 2)	–	180 steel, 30 Inconel, 25 Hastelloy, 15 gold, 30 silicon, 15 electrum	–	120 steel, 90 copper, 30 Invar, 20 electrum, 15 Astroloy

Everything that grows with size (pump, core heat capacity and heat transfer, steam drum, own use) grows by the same factor of 1.5. That is why the large reactor behaves exactly like the small one: same core temperature in operation (586 K), same warning levels, and the same timings when the feed pump fails (pre-warning after 24 s, alarm after 60 s, scram after 79 s). Each rod lasts 4 hours at full load – the large reactor uses 9 rods per 4 hours.

Large reactor connections (floor level): back main steam (x +0.5, gas pipe only), power (centre), feedwater (x -0.5, liquid pipe only); front data below the control panel. The fuel hatch sits front left with a row of 9 slots, the control panel front right – all controls between 0.4 and 1.3 m, easy to reach from the character's eye height.

Large turbine connections: left (+X) main steam, right (-X) power (super-heavy cable), back condensate (x +1.0), cooling water in (x 0) and out (x -1.0), front data (x -1.5).

The control room runs both like the small machines; "SET MW" splits the output in proportion to each turbine's rated power.

Radiation shield gate#

A heavy sliding gate for a 2 m wall face, built like a door. Closed it is airtight like the game doors and keeps out 99.9 % of the radiation (a wall or game door keeps out 50 %). Side A is the side with the connections (power and data at the floor), side B the opposite one. Both sides have their own control panel.

Control	Function
Display (4 lines)	state, dose rate here and behind, most important message
LED CLEAR (green)	gate can be operated normally
LED STOP (red)	fast flashing: lockdown or obstacle; steady: locked (IC10 Lock) or airlock partner open
LED PROTECT (yellow)	towards the radiation side only with the set protection level
Button OPEN / CLOSE (green)	opens or closes via the airlock logic
EMERGENCY OPEN (red mushroom)	from the radiation side: always opens, even in lockdown or when locked, for 15 s
Beacon on the lintel	yellow while moving, red during lockdown and emergency open (with light and double tone)

Airlock: gates with the same airlock group (IC10 put address 3, values 1–99) on the same data network are never open at the same time. OPEN first closes the open partner, then opens.

Lockdown: if the dose rate on either side reaches the threshold (default 1 mSv/h, per gate via IC10 Setting) or a radiation monitor or detector on the data network alarms, the gate closes immediately and locks. It is released with OPEN, IC10 Activate 0 or ACK at the control room – but only once the radiation has dropped below 80 % of the threshold and no monitor is alarming any more. From outside, OPEN during a lockdown only works with the full protective set (level 3).

Nobody gets locked in: EMERGENCY OPEN on the radiation side always opens the gate for 15 s (waiting at most 4 s for the airlock partner). Then it closes again if the lockdown still applies.

Obstacle: if someone stands or something lies in the doorway, the gate does not close or opens again – with a warning tone and a flashing STOP LED.

Without power (150 W) only a crowbar moves the gate, as with the game doors.

IC10	read	write
Open	1 open	1 open, 0 close (via the airlock logic)
Lock	buttons locked	1 lock (emergency open stays)
Activate	1 lockdown	1 trigger, 0 release
Setting	threshold (mSv/h)	set threshold
Quantity	higher dose rate of both sides	–
Ratio	opening 0–1	–
Error	obstacle or no power	–
Maximum	shielding in %	–

Memory (get/put): 0 dose rate side A, 1 side B, 2 threshold, 3 airlock group, 4 minimum protection level (0–3), 5 radiation side (0 automatic, 1 A, 2 B), 6 lockdown, 7 trigger (1 measurement, 2 monitor, 3 manual/IC10/control room), 8 obstacle, 9 opening, 10 open partners, 11 emergency open time left, 12 partners, 13 shielding, 14 waiting for partner.

Control room: get 20 number of gates on the data network, 21 of them in lockdown; put 22 1 = lock down all, 0 = release all.

Example: radiation airlock at the large reactor#

Two gates form the airlock in front of the reactor room. The inner gate only opens towards the reactor with a radiation suit, the outer gate stays locked while the fuel hatch is open, and a flashing light warns of radiation or lockdown. Name the devices "Schleuse Innen", "Schleuse Aussen", "Grossreaktor" and "Warnlicht Schleuse" (or change the names in the script).

# --- Strahlenschleuse am Großreaktor (Atomkraftwerk 1.1.0) ---
# Geräte benennen: Tore "Schleuse Innen" (zum Reaktor) und "Schleuse Aussen",
# Reaktor "Grossreaktor", Blinklicht "Warnlicht Schleuse". Alle im Datennetz.
define TOR 505144048        # Strahlenschutztor (StructureAkwSchutztor)
define REAKTOR -617319356   # Großreaktor (StructureAkwReaktorGross)
define LAMPE -1535893860    # Blinklicht (StructureFlashingLight)
define AVG 0                # Batchmodus Durchschnitt
define GRUPPE 1             # Schleusengruppe beider Tore: nie beide offen
define SCHUTZ 2             # Innentor zum Reaktor nur ab Schutzstufe 2
define INNENSEITE 2         # Innentor: Seite B (ohne Anschlüsse) zeigt zum Reaktor
define WARN 0.5             # mSv/h  Warnlicht ab dieser Dosisleistung
define ADR_GRUPPE 3         # Torspeicher: Schleusengruppe
define ADR_SCHUTZ 4         # Torspeicher: Mindest-Schutzstufe
define ADR_INNEN 5          # Torspeicher: Strahlenseite (0 auto, 1 A, 2 B)
alias nInnen r0
alias nAussen r1
alias nReaktor r2
alias nLampe r3
alias ref r4
alias dosis r5
alias luke r6
alias warn r7
alias zu r8

# --- 1. Namen und Toreinstellungen (einmal beim Start) ---
move nInnen HASH("Schleuse Innen")
move nAussen HASH("Schleuse Aussen")
move nReaktor HASH("Grossreaktor")
move nLampe HASH("Warnlicht Schleuse")
lbn ref TOR nInnen ReferenceId AVG
put ref ADR_GRUPPE GRUPPE
put ref ADR_SCHUTZ SCHUTZ
put ref ADR_INNEN INNENSEITE
lbn ref TOR nAussen ReferenceId AVG
put ref ADR_GRUPPE GRUPPE

# --- 2. Hauptschleife ---
haupt:
yield
# Ladeluke offen: Außentor sperren (NOT-AUF von innen bleibt frei)
lbn luke REAKTOR nReaktor Open AVG
sbn TOR nAussen Lock luke
# höchste Dosisleistung an beiden Toren
lbn dosis TOR nInnen Quantity AVG
lbn warn TOR nAussen Quantity AVG
max dosis dosis warn
# Warnlicht: Dosis über WARN, Luke offen oder ein Tor abgeschottet
sgt warn dosis WARN
or warn warn luke
lbn zu TOR nInnen Activate AVG
or warn warn zu
lbn zu TOR nAussen Activate AVG
or warn warn zu
sbn LAMPE nLampe On warn
j haupt

Adjust: WARN (warning threshold in mSv/h), SCHUTZ (0 = no check, 3 = full radiation protection only), INNENSEITE (which side of the inner gate faces the reactor). For the small reactor set REAKTOR to -1132390847. If a device fails or a name is missing, lbn reads 0: the warning light then stays off and the outer gate unlocked – the gates' own lockdown keeps working regardless.

Transport cask and fuel rod carrier#

	Transport cask	Fuel rod carrier
Slots	9 rods standing in wells	3 rods lying down
Shielding closed	99.99 %	99.9 %
Lid open	half escapes	half escapes
Example: freshly spent rods	9 rods (18 Sv/h) → 1.8 mSv/h at 1 m outside	3 rods → 6 mSv/h at 1 m
Transport	pull by the handle, wrench onto a rover or container mount	hand, backpack, crates, chutes
Made in	kit from the Autolathe (40 steel, 100 lead, 10 iron)	Autolathe (5 steel, 20 lead)

Right-click in hand opens and closes the carrier's lid. Both containers are paintable.

Radioactive uranium ore#

Uranium ore radiates weakly – in hand, in the inventory, in crates, lockers and rovers, on the ground and freshly mined. Per piece 0.001 mSv/h at 1 m (setting UranerzMSvJeStueck, switch off with ErzStrahlungAktiv).

Situation	Dose rate
a full stack (50) in hand or inventory	0.2 mSv/h
the same stack on the ground, 1 m away	0.05 mSv/h
500 ore in a crate, 1 m in front (the crate dampens 30 %)	0.35 mSv/h
the same crate behind a wall, 3 m	0.02 mSv/h

An 8-hour working day next to the ore crate adds up to about 3 mSv – far below the damage threshold of 250 mSv. So ore is no reason to panic, but the Geiger counter ticks, and large ore stores do not belong next to your bed. Further radioactive ores from other mods can be added with ErzWeitere (e.g. ItemThoriumOre=0.0005).

New console commands#

Command	Effect
akw tor	radiation shield gates nearby with their state
akw tor abschotten / akw tor frei	lock down or release the nearest gate
akw tor gruppe 1 / innen 2 / schutz 2 / schwelle 0.5	airlock group, radiation side, protection level, threshold of the nearest gate
akw erz	radioactive ore stacks and merged sources nearby
akw behaelter [frisch|abgebrannt]	fill the nearest transport cask or carrier with test rods

New settings#

Section	Setting	Default
12 Transport	BehaelterAbschirmungProzent, KoecherAbschirmungProzent, BehaelterOffenProzent, LagerDaempfungProzent	99.99 / 99.9 / 50 / 30
13 Uranerz	ErzStrahlungAktiv, UranerzMSvJeStueck, ErzWeitere, ErzTaktSekunden	on / 0.001 / empty / 2
14 Strahlenschutztor	TorAbschirmungProzent, TorSchwelleMSv, TorMonitoreAusloesen, TorLaufzeitSekunden, TorNotAufSekunden, TorMindestschutz, TorAbschottungOeffnenAbSchutz, TorStromW	99.9 / 1 / on / 3 / 15 / 0 / 3 / 150

Warning levels#

Level	When	What happens
Normal	core below 600 K	–
Notice	core at 600 K or more and rising, or a minor warning	yellow on the display
Pre-warning	core at 650 K	yellow LED, yellow beacon, calm notice tone
Alarm	core at 750 K	red LED and warning light, fast loud beeps at the reactor, horn on the control room desk until ACK
Scram	core at 800 K (not in hardcore)	all control rods in at once, AUTO off, own tone until ACK
Core damage	core at 1100 K	countdown "MELTDOWN IN xx s", siren, also in hardcore
Meltdown	30 s above 1100 K	see Meltdown

Every warning gives the estimated time to the next level. The limits are adjustable (section "2 Warnstufen").

Early warnings#

Besides the core temperature the reactor reports what is about to cause trouble, again with time left: feedwater low or empty, steam pressure high, relief valve venting, rod over 90% burnt, no fuel rods, no power (pump stopped), no main steam or feedwater pipe, fuel hatch open, turbine or cooling tower fault.

Sounds#

Occasion	Sound (default)	Where and how
Pre-warning	LogicError	reactor and control room desk: two calm beeps every 4 s, 25 m range
Alarm	Alarm2 and LogicError	control room desk: horn until ACK; reactor: three fast, loud beeps every 2 s, 45 m range
Scram	Alarm7	reactor and control room desk: loud when triggered, then every 8 s until acknowledged on the desk
Core damage	Alarm10	continuous rising and falling siren at reactor and control room desk
Fault	Error	turbine (trip, hot condenser, no cooling water) and cooling tower (not cooling, water low), every 5 s
Radiation	LogicError	radiation monitor three beeps every 2 s (35 m), radiation detector one beep every 1.5 s (20 m), Geiger counter two beeps per second from 100 mSv/h

• If you switch the reactor off with its main switch, there is no scram tone – the shutdown is intended then.
• In vacuum (below 3 kPa) nothing can be heard. The control room desk then shows "Vacuum - sounds muted".
• The running sounds of reactor, turbine, cooling tower and control room desk can only be heard up to 25 m. Alarms and sirens carry further.
• All sounds can be swapped in the settings or switched off with AlarmTonAn. akw tontest plays them for testing.

What happens if …#

Results from the simulator with default values. Starting point: 40 minutes of AUTO operation at 1 MW.

Fault	Course
Cooling tower fails, reactor MANUAL	turbine trip after 5 s, relief valve after 4 s, "feedwater low" after 5 s, pre-warning after 58 s, alarm after 95 s, scram after 114 s
Cooling tower fails, reactor AUTO	trip after 5 s, AUTO powers down at once, no pre-warning. The feedwater slowly boils off through the relief valve with the decay heat.
Feed pump without power, MANUAL at full power	pre-warning after 24 s, alarm after 60 s, scram after 79 s, at most 832 K
the same in hardcore	pre-warning 24 s, alarm 60 s, 800 K after 79 s without shutdown, core damage after 189 s, meltdown after 218 s
Load steps 1 → 0.4 → 1 MW	drum at most 1400 kPa, no relief valve, no oscillation
Load rejection 1 → 0 → 1 MW	bypass up to 226 mol/s, drum at most 1452 kPa, no venting
After a scram, cooling running	core drops to 553 K
After a scram without cooling	core rises slowly: 596 K after 1 min, 620 K after 10 min, 644 K after 1 h – just below the pre-warning

AUTO handles a cooling tower failure. Make sure the feed pump's power is secure: without it there are only 24 s to the pre-warning at full power.

Resetting a scram#

A scram can only be reset once the core is below 650 K and there is no meltdown. Then you have these options:

• ACK on the control room desk when no alarm is open any more (also resets the turbine trip)
• the reactor's main switch OFF and ON again
• IC10: Activate to 0
• console: akw reset (host)

Then switch AUTO back on.

Meltdown#

Sequence#

1. From 1100 K the core takes damage. Display and control room desk show "MELTDOWN IN xx s (core damage y %)", the siren sounds – in hardcore too.
2. If the core stays above 1100 K for 30 s, it melts.
3. There is an explosion at the core: strength 60, radius = strength / 5, i.e. 12 m. Players and structures nearby take damage. The reactor itself stays standing as a device.
4. The reactor becomes a wreck: charred dark, with debris, smoke and steam for 30 minutes. It stays off for good and the fuel hatch is jammed. Fresh rods in the core count as melted.
5. A contaminated zone forms around the reactor: 100 Sv/h at the centre, radius 10 m.

The contaminated zone#

Inside the radius the radiation drops to half towards the edge, outside it falls with the square of the distance. Walls only shield outside the radius. There is radioactive dust in the air inside the zone (see Inhalation).

Distance from the centre	Dose rate right after the meltdown
0 m	100 Sv/h
5 m	75 Sv/h
10 m (edge)	50 Sv/h
15 m	22.2 Sv/h
20 m	12.5 Sv/h
40 m	3.1 Sv/h (behind two walls 0.78 Sv/h)

The zone decays (time constant 3 hours):

Time after the meltdown	Centre of the zone
1 h	71.7 Sv/h
3 h	36.8 Sv/h
9 h	5 Sv/h
24 h	33.5 mSv/h

Cleaning up#

• akw zone entfernen clears the nearest zone at once (host).
• akw reset restores the nearest reactor: meltdown, core damage and scram reset, wreck gone.
• Zones are stored in the save.

Switching meltdown off#

• KernschmelzeAktiv off: the core takes no damage any more. Alarm and scram still happen.
• ExplosionAktiv off: the meltdown happens without an explosion.
• Explosion strength, size, strength and decay time of the zone and how long the smoke lasts are adjustable (section "8 Kernschmelze").

Hardcore#

With Hardcore on there is no automatic scram. You have to shut down yourself: E-STOP, main switch, SCRAM on the control room desk, IC10 or console. The displays show "HARDCORE" instead of the scram limit. Countdown and siren on core damage remain.

Radiation#

How it is calculated#

• The unit is mSv/h. The server calculates once per second.
• A source with strength S (at 1 m) gives the dose rate S / r² at distance r. Below 0.5 m the distance is not reduced further, so an item in the hand counts as 0.5 m: four times as much.
• Every wall, door or structure between source and player keeps out 50%. At most four count, terrain counts double.
• Natural background is 0.2 µSv/h.
• Items in the inventory sit at the chest height of their carrier.
• Rods and barrels in the reactor or bunker count there, with its shielding.

Sources#

Source	Dose rate at 1 m
Reactor running, hatch closed	0.3 mSv/h per MW of heat, just under 1 mSv/h at full power (0.11 mSv/h at 3 m)
Open fuel hatch 10 min after a scram (6 rods, 50% burnt)	2.7 Sv/h (680 mSv/h at 2 m, 27 mSv/h at 10 m)
Fresh fuel rod	0.02 mSv/h
Fuel rod with 50% burnup	400 mSv/h
Freshly spent fuel rod	2 Sv/h, 8 Sv/h in the hand, 80 mSv/h at 5 m
Decayed fuel rod	0.01 mSv/h
Fresh nuclear waste barrel	40 mSv/h, 160 mSv/h in the hand
Nuclear waste bunker with 12 freshly spent rods	door closed 2.4 mSv/h, door open 6 Sv/h
Reprocessing plant running with 12 rods in stock (1 h decayed)	17.3 mSv/h
Wreck after a meltdown	2% of the rods in the core, plus the zone

Dose and damage#

• The dose adds up per player.
• Up to 250 mSv nothing happens. Above that you take radiation damage. About 5 Sv more is lethal.
• Away from radiation (below 0.01 mSv/h) the body recovers 20 mSv per hour.
• Radiation damage heals like other damage: medkit, sleep.
• akw dosis shows your dose, akw dosis 0 resets it (host).
• With StrahlungAktiv off all devices keep measuring, but nobody takes damage.

Protection levels#

Gear	Protection against radiation from outside
nothing, helmet open or only a gas mask	0%
normal space suit with closed helmet	50%
radiation suit with closed game helmet	75%
radiation suit with closed radiation helmet	95%

The radiation helmet on a normal suit counts as a normal helmet (50%). akw schutz shows your gear and protection level, and so does the Geiger counter's tooltip.

Radiation Suit: an Eva suit with lead lining, warning yellow. All functions of the Eva suit remain: air, filters, temperature, battery, slots. It can be repainted with a spray can.

Radiation Helmet: a space helmet with a lead-glass visor, amber tinted. It works like the space helmet.

Inhalation#

In the contaminated zone, within 5 m of a nuclear waste barrel and within 5 m of an open bunker there is radioactive dust in the air. Anyone breathing outside air there (no helmet or helmet open) gets an extra internal dose – with the default value as much as from outside, so double. A closed helmet or a gas mask prevents it. If the mask has a visor, it only counts when closed.

How long can you stay?#

Place	no protection	suit + helmet	radiation suit + game helmet	full radiation gear
Centre of the zone, 5 min after the meltdown (97 Sv/h)	1.6 min (breathing dust)	6.5 min	13 min	65 min
10 m from the centre (49 Sv/h)	3.2 min	13 min	26 min	2.2 h
20 m from the centre (12 Sv/h, no dust)	26 min	52 min	1.7 h	8.6 h

The times are until death (simulator). More examples:

Situation	no protection	suit + helmet	full radiation gear
6 freshly spent rods for 30 s in the inventory (48 Sv/h)	400 mSv, above the threshold	200 mSv	20 mSv
1 freshly spent rod for 30 s in the hand	67 mSv	33 mSv	3 mSv
60 s at 2 m in front of the open hatch, 10 min after a scram	11 mSv	6 mSv	1 mSv
30 min at 1 m next to a fresh barrel	40 mSv (breathing dust)	10 mSv	1 mSv

Practical rules#

• With the hatch closed the reactor is hardly dangerous.
• Before opening the hatch, check the FUEL RODS display page. Wear the radiation suit and helmet when changing rods.
• Don't carry spent rods around in the inventory; put them straight into the bunker.
• Distance helps most: double the distance, a quarter of the radiation. Every wall halves it.
• Put radiation monitors and detectors where people work.

Measuring devices#

Geiger Counter: in the hand or the tool belt it clicks according to the dose rate – now and then from background, faster and faster near a source, from about 1 mSv/h it crackles. The small display shows the dose rate and your accumulated dose, the needle runs logarithmically from 0.1 µSv/h to 10 Sv/h. The warning LED lights up from 1 mSv/h, and from 100 mSv/h it also beeps loudly. It measures the radiation at the wearer without the suit's protection. The tooltip also shows the damage threshold, your protection level and whether you are inhaling dust.

Radiation Monitor: wall device with display, warning light and signal tone. It measures once per second 0.3 m in front of the device. The housing is 22 cm deep: front and buttons stay visible in front of any finished wall, even if the wall is finished afterwards (since 1.0.2).

• Alarm limit 0.5 mSv/h by default, adjustable with - and + in steps of 1–2–5.
• Above half the limit WARNING lights up. Above the limit the red warning light flashes with real light and a fast signal tone sounds. MUTE silences it until the value drops below the limit again.
• Display pages: RADIATION (value, limit, peak, strongest source), SOURCES (the three strongest with type and distance), REPORTS (fuel hatch open, rod or barrel loose, contamination).
• Reports to the control room desk: radiation high (with horn) or raised, fuel hatch open, spent rod or barrel outside the bunker, contamination, no power.
• Connection at the top centre, power and data in one cable, 20 W.

Radiation Detector: small, cheap detector without a display for wall or ceiling. It sits on a mounting box and so stays visible in front of a finished wall or ceiling too (since 1.0.2). It measures 0.3 m in front of its mounting surface.

• Status LED: green normal, yellow from half the alarm limit, flashing red above it. Plus a short beep that MUTE silences until the value drops below the limit again.
• Alarm limit 0.5 mSv/h by default, adjustable via IC10.
• Reports "DETECTOR ALARM" to the control room desk, with its name or its position. You give it a name with the labeller.
• 5 W, connection on top.

Waste disposal#

Decay#

Spent rods decay. After the cooling time (4 real-time hours by default) hardly anything is left.

Time since the rod was spent	Activity	Dose rate at 1 m
0	100%	2 Sv/h
10 min	52%	1.04 Sv/h
30 min	20%	393 mSv/h
1 h	7%	142 mSv/h
2 h	1.2%	24 mSv/h
4 h	0.04%	0.73 mSv/h

The nuclear waste barrel decays much more slowly, with a half-life of 48 hours: 40 mSv/h fresh, 20 mSv/h after 2 days, 3.5 mSv/h after a week.

Nuclear Waste Bunker#

• Heavy lead-lined cabinet with 12 slots on three levels behind a heavy door. It only takes spent and decayed rods and nuclear waste barrels.
• The DOOR button opens and closes it. The slots can only be reached with the door open.
• With the door closed it keeps out 99.99% of the radiation; with the door open a quarter escapes. So only open it to load and unload.
• The shielding needs no power. Display and LEDs use 50 W.
• Spent rods decay here. After the cooling time each one turns into a Fuel Rod (decayed) – harmless and recyclable.
• Display pages: WASTE BUNKER (occupancy, activity inside, leaking at 1 m, next decayed in, door), SLOTS 1-6 and SLOTS 7-12 with time left per slot.
• Slot display with 12 fields: orange = decaying, green = decayed, yellow = barrel.
• LEDs: RUN, DOOR OPEN, FULL, RADIATION, DATA.
• Reports to the control room desk: full, door open, rods decayed.

12 slots are two reactor loads. At full power the previous load has decayed by the time the next one comes out.

Reprocessing Plant#

• A hot cell with a lead glass window and manipulators. It takes spent and decayed rods via the chute on the left (+X, at 0.5 m height) or the airlock on top into its stock, up to 12.
• 3 rods become one new fuel rod and one nuclear waste barrel (vitrified fission products) in 120 s at 20 kW.
• Output via the output tray or the chute on the right (−X), rod first, then barrel. Anything else is passed through.
• Radiation: 0.3 mSv/h at 1 m while running, plus 1% of the stock's activity. The stock keeps decaying.
• Controls: main switch, START/STOP, PAGE < / >, progress bar.
• Display pages: REPROCESSING (stock, progress, new rods and barrels, state) and PROCESS.
• States: REPROCESSING, OUTPUTTING, WAITING FOR RODS, OUTPUT BLOCKED, FOREIGN ITEM - passed through, STOP, OFF.

Fuel cycle#

Route	Result
12 spent rods through the reprocessing plant	4 cycles in 8 min, 4 new rods + 4 barrels, 9.6 MJ of power, saves 80 uranium ore
per reactor load (6 rods)	6 spent → 2 new + 2 barrels. You then only need 4 rods from the factory (80 uranium ore) instead of 6 (120)
decayed rod in the game's recycler	3 steel

The game's recycler does not accept spent rods or barrels; it throws them back out.

IC10#

Device	Prefab	Hash
Reactor (Boiling Water)	StructureAkwReaktor	-1132390847
Steam Turbine 1 MW	StructureAkwTurbine	150538141
Cooling Tower	StructureAkwKuehlturm	-1365120482
Control Room Desk	StructureAkwLeitstand	1677455470
Fuel Rod Factory	StructureAkwBrennstabFabrik	1277732781
Nuclear Waste Bunker	StructureAkwBunker	-478813853
Reprocessing Plant	StructureAkwRecycler	-259178611
Radiation Monitor	StructureAkwStrahlungsmonitor	-1539374058
Radiation Detector	StructureAkwStrahlenmelder	-923417679

Item	Prefab	Hash
Fuel Rod (Uranium)	ItemAkwBrennstab	953339804
Spent Fuel Rod	ItemAkwBrennstabVerbraucht	-554619789
Fuel Rod (decayed)	ItemAkwBrennstabAbgeklungen	-596721571
Nuclear Waste Barrel	ItemAkwAtommuell	-923965377
Geiger Counter	ItemAkwGeigerzaehler	-239920569
Radiation Suit	ItemAkwStrahlenschutzanzug	-1181358099
Radiation Helmet	ItemAkwStrahlenschutzhelm	-2098193955

LogicTypes work through lbn/sbn with the device name. Memory addresses are read and written with get/put; for that the device has to be on a pin, or you use its ReferenceId. Writable addresses are marked (W). Temperatures are in kelvin, power in W, dose rates in mSv/h.

Warning level (Stress)#

Value	Level
0	Normal
1	Notice
2	Pre-warning
3	Alarm
4	Scram
5	Core damage
6	Meltdown

Reactor#

LogicType	Read/Write	Meaning
On	R/W	main switch
Mode	R/W	0 MANUAL, 1 AUTO
Setting	R/W	control rod setpoint in % inserted; writing switches to MANUAL
Throttle	R	control rods actual in %
Activate	R/W	1 = scram, 0 = reset (only below 650 K)
Temperature	R	core temperature
Pressure	R	drum pressure in kPa
PressureSetting	R	AUTO pressure setpoint in kPa
PowerGeneration	R	thermal power
Ratio	R	thermal power / rated power
Maximum	R	rated power (3 MW)
Stress	R	warning level 0–6
Error	R	1 from alarm
Open	R/W	fuel hatch
Fuel	R	fuel of all rods, 0–1 (1 = six full rods)
BurnTimeRemaining	R	seconds until the first rod is empty (−1 = reactor idle)
RequiredPower	R	power draw
…Input / …Output	R	feedwater pipe / main steam pipe, e.g. PressureOutput

Address	Meaning
0	core temperature
1	thermal power
2	fission power
3	decay heat
4	control rods actual in %
5	control rods setpoint in % (W)
6	steam in mol/s
7	feedwater stock in mol
8	feedwater empty in s (−1)
9	drum pressure in kPa
10	pressure limit in kPa
11	warning level 0–6
12	seconds to the next level (−1)
13	core damage in %
14–19	burnup of rods 1–6 in % (−1 empty, 101 spent)
20	temperature change in K/s
21	display page 0–3 (W)
22	fuel hatch 1/0 (W)
23	hardcore 1/0
24	total heat in MWh
25	operating hours
26	total vented in mol
27	AUTO 1/0 (W)
28	scram 1/0 (W)
29	radiation at the fuel hatch when open, at 1 m
30	radiation outside the reactor at 1 m
31	minutes since the meltdown (−1)

clr resets the statistics (24–26).

Steam turbine#

LogicType	Read/Write	Meaning
On	R/W	main switch
Mode	R/W	0 AUTO, 1 MANUAL
Setting	R/W	power limit in W; writing switches to MANUAL
Maximum	R	rated output
PowerGeneration, PowerActual	R	delivered power
Ratio	R	load
Activate	R/W	trip: 1 trigger, 0 reset
Temperature	R	condenser temperature
Pressure	R	condenser pressure in kPa
Rpm	R	speed
WorkingGasEfficiency	R	efficiency 0–1
Error	R	1 = fault
…Input / …Output	R	main steam / condensate
…Input2 / …Output2	R	cooling water in / out

Address	Meaning
0	delivered power
1	power limit
2	possible power
3	network demand
4	cable limit (−1 = no network)
5	steam in mol/s
6	bypass in mol/s
7	main steam temperature
8	condenser temperature
9	condenser pressure in kPa
10	efficiency 0–1
11	cooling water in, temperature
12	cooling water out, temperature
13	cooling water in mol/s
14	waste heat into the condenser
15	total power in MWh
16	operating hours
17	speed
18	display page 0–3 (W)
19	governor 0 AUTO, 1 MANUAL (W)
20	trip 1/0 (W)

clr resets the statistics.

Cooling tower#

LogicType	Read/Write	Meaning
On	R/W	main switch
PowerActual	R	heat rejected
Maximum	R	possible heat rejection with the current air
Ratio	R	heat rejected / maximum
Temperature	R	cold water
TemperatureExternal, PressureExternal	R	outside air
Error	R	1 = fault
RequiredPower	R	power draw
…Input / …Output	R	warm water / cold water

Address	Meaning
0	heat rejected
1	possible heat rejection
2	warm water
3	cold water
4	outside air temperature
5	outside air in kPa
6	pressure factor (draught) 0–1
7	water flow in mol/s
8	evaporation in mol/s
9	total evaporated in mol
10	water in the cooling loop in mol
11	stock lasts for s (−1)
12	total heat in MWh
13	operating hours
14	display page 0–2 (W)

clr resets the statistics.

Control room desk#

LogicType	Read/Write	Meaning
On	R/W	main switch
Mode	R/W	view 0–3
Setting	R/W	turbine setpoint in W, 0 = on demand
Activate	R/W	write 1 = scram all reactors; read 1 = at least one reactor in scram
Stress	R	highest warning level of the plant
Error	R	1 = open alarm (horn)
PowerGeneration	R	power of all turbines

Address	Meaning
0 / 1 / 2 / 3	number of reactors / turbines / cooling towers / factories on the data network
4	highest warning level 0–6
5	power of all turbines
6	thermal power of all reactors
7	setpoint in W (W)
8	view 0–3 (W)
9	write 1 = press ACK (W)
10	horn 1/0
11 / 12 / 13	number of radiation monitors / nuclear waste bunkers / reprocessing plants
14	highest dose rate of the monitors
15	total occupied bunker slots
16	contaminated zones
17	scram not acknowledged 1/0
18	radiation detectors on the data network
19	radiation detectors in alarm

Fuel rod factory#

LogicType	Read/Write	Meaning
On	R/W	main switch
Activate	R/W	production on/off
Ratio, Progress	R	progress 0–1
Quantity	R	rods produced
Error	R	foreign item or no power

Address	Meaning
0	uranium ore in store
1	steel in store
2	progress in %
3	rods produced
4	uranium ore per rod
5	steel per rod
6	seconds to the next rod (−1)
7	display page 0–1 (W)
8	production on 1/0 (W)

clr resets the counter of rods produced.

Nuclear waste bunker#

LogicType	Read/Write	Meaning
On	R/W	main switch
Open	R/W	door
Lock	R/W	lock the door
Quantity	R	occupied slots
Maximum	R	12
Ratio	R	occupancy 0–1
Error	R	1 = full
Setting	R	decayed rods in the bunker

Slots 0–11 can be read with ls, for example OccupantHash.

Address	Meaning
0	occupied slots
1	spent rods
2	barrels
3	decayed rods
4	activity inside at 1 m, unshielded
5	leaking at 1 m
6	next rod decayed in s (−1)
7	total decayed
8	door (W)
9	lock (W)
10	display page 0–2 (W)
11–22	slot 1–12: −1 empty, −2 barrel, −3 other, 0 decayed, otherwise remaining cooling time in s

clr resets the counter (address 7).

Reprocessing plant#

LogicType	Read/Write	Meaning
On	R/W	main switch
Activate	R/W	operation on/off
Ratio, Progress	R	progress 0–1
Quantity	R	rods in stock
Setting	R	total new rods
Error	R	foreign item, output blocked or no power

Address	Meaning
0	rods in stock
1	progress in %
2	total new rods
3	total barrels
4	seconds until done (−1)
5	activity of the stock at 1 m, unshielded
6	rods per cycle
7	display page 0–1 (W)
8	operation on 1/0 (W)
9	items still to be output

clr resets the counters (2 and 3).

Radiation monitor#

LogicType	Read/Write	Meaning
On	R/W	main switch
Setting	R/W	alarm limit in mSv/h
Quantity	R	dose rate
Ratio	R	dose rate / limit
Maximum	R	peak
Error	R	1 = above the limit
Activate	R/W	mute
Mode	R/W	display page 0–2

Address	Meaning
0	dose rate
1	alarm limit (W)
2	peak
3	sources nearby
4–6	dose rate of the three strongest sources here
7–9	their distance in m
10–12	their type: 1 reactor, 2 fresh rod, 3 spent rod, 4 barrel, 5 zone, 6 bunker, 7 reprocessing plant, 8 decayed rod, 9 open fuel hatch
13	share of the zone
14	display page (W)
15	mute (W)

clr resets the peak.

Radiation detector#

LogicType	Read/Write	Meaning
On	R/W	main switch
Setting	R/W	alarm limit in mSv/h
Quantity, Ratio	R	dose rate in mSv/h
Activate	R	1 = alarm
Maximum	R	peak
Error	R	1 = no power

Example: show the core temperature, own scram#

The reactor is named "Reaktor" (reactor), an LED Display (Small) "Kern" (core). The display shows the core temperature in °C: green in normal operation, yellow from the pre-warning, red from the alarm. When the core reaches 780 K, the chip triggers a scram – 20 K before the automatic one. In hardcore mode, where there is no automatic scram, it takes over that job.

# NPP: show core temperature, own scram
define REAKTOR -1132390847  # Reactor (Boiling Water)
define ANZEIGE -815193061   # LED Display (Small)
define GRENZE 780           # 780 K = 507 C own scram limit
define CELSIUSOFFSET 273.15 # Kelvin to Celsius
define VORWARNUNG 2         # warning level pre-warning
define ALARM 3              # warning level alarm
define GRUEN 2              # Color.Green
define GELB 5               # Color.Yellow
define ROT 4                # Color.Red
alias kern r0
alias stufe r1
alias farbe r2
alias pruef r3
alias anzeige r4
start:
yield
lbn kern REAKTOR HASH("Reaktor") Temperature 0
bnan kern start
lbn stufe REAKTOR HASH("Reaktor") Stress 0
sge pruef stufe VORWARNUNG
select farbe pruef GELB GRUEN
sge pruef stufe ALARM
select farbe pruef ROT farbe
blt kern GRENZE zeigen
sbn REAKTOR HASH("Reaktor") Activate 1
zeigen:
sub anzeige kern CELSIUSOFFSET
sbn ANZEIGE HASH("Kern") Setting anzeige
sbn ANZEIGE HASH("Kern") Color farbe
j start

• Adjustable: GRENZE (limit, in kelvin; keep it below the damage limit of 1100 K).
• Reactor not found (named differently or deconstructed): lbn returns no value, the chip waits in the loop and writes nothing.
• You have to reset the scram yourself once the core is below 650 K, see Resetting a scram.

Console commands#

Open the console with F3. Commands that change something only work on the host or server, or in single player. "Nearest" means the device closest to you.

Command	Effect	host only
akw status	all plant parts with state and warnings, pressure limit, radiation, zones	–
akw scram	scram of all reactors	yes
akw reset	reset the nearest reactor: meltdown, core damage, scram, plus the trip of its turbine	yes
akw reset kalt	as above and cool the core to 20 °C	yes
akw testanlage	make the nearest plant ready: 6 fuel rods, water in the feedwater and cooling water pipes, factory store for 6 rods, everything switched on	yes
akw temp 700	set the core temperature of the nearest reactor in kelvin, e.g. to test the warning levels	yes
akw abbrand 95	set the burnup of all rods in the nearest reactor in %	yes
akw strahlung	sources and dose near you, protection, inhalation, dust	–
akw dosis	your dose, dose rate and radiation damage	–
akw dosis 0	set your dose to 0	yes
akw zone	contaminated zones with distance, strength, radius and age	–
akw zone entfernen	remove the nearest zone	yes
akw zone test	weak test zone at your position: 50 mSv/h, radius 5 m	yes
akw abklingen 4	set all spent rods to this cooling time in hours, e.g. to test the bunker	yes
akw recycler	fill the stock of the nearest reprocessing plant with 3 spent rods	yes
akw tontest alarm	warning sound at the nearest matching device, only on your computer. Types: vorwarnung, alarm, scram, schmelze, stoerung	–
akw schutz	your gear, protection level and inhalation	–

Configuration#

File: BepInEx\config\dominik1199.atomkraftwerk.cfg, or through the mod settings in LaunchPad. The keys are in eleven sections. The mod applies changes right away. In multiplayer the server's values apply.

1 Reaktor (reactor)

Key	Default	Meaning
BrennstabLeistungMW	0.5	thermal power of one rod with control rods fully withdrawn
BrennstabStunden	4	real-time hours a rod lasts at full power
FrischdampfC	280	main steam temperature in °C
DampfHoechstKPa	8000	relief valve; effective at most 92% of the vapor pressure at FrischdampfC (about 1670 kPa at 280 °C)
DruckSollProzent	75	AUTO keeps the drum at this % of the pressure limit
PumpeMolJeTakt	200	maximum feedwater the reactor evaporates per tick
KernWaermekapazitaetMJjeK	2.1	heat capacity of the core; larger = more time until scram
WaermeuebergangKWjeK	86	heat transfer core → water per kelvin above steam temperature
KernVerlustWjeK	10	heat loss of the core to the air per kelvin
EigenbedarfKW	20	power draw with the feed pump at full, controls alone 10%
StabGeschwindigkeitProzentJeS	5	control rod speed
LeistungZeitkonstanteS	10	inertia: seconds for 63% of a power change
Hardcore	off	no automatic scram

2 Warnstufen (warning levels)

Key	Default	Meaning
VorwarnungK	650	core temperature of the pre-warning
AlarmK	750	core temperature of the alarm
NotabschaltungK	800	core temperature of the automatic scram
KernschadenK	1100	above this the core takes damage
SchmelzSekunden	30	time above the damage temperature until meltdown
KernschmelzeAktiv	on	off = the core takes no damage

3 Turbine

Key	Default	Meaning
TurbineMaxMW	1	maximum electrical output
WirkungsgradProzent	35	share of the steam energy that becomes power
KondensatC	40	condensate temperature in normal operation
KuehlwasserMolJeTakt	4000	maximum cooling water flow of the condenser pump
KondensatorWarnC	60	warning from this condenser temperature
SchnellschlussC	90	trip from this condenser temperature
UmleitungAbProzent	85	bypass from this % of the pressure limit
UmleitungMaxProzent	100	at most this % of the rated steam flow through the bypass, 0 = none
KabelReserveProzent	95	the turbine offers at most this % of the weakest cable

4 Kuehlturm (cooling tower)

Key	Default	Meaning
KuehlturmMaxMW	2.5	maximum heat rejection
KuehlleistungKWjeK	120	heat rejection per kelvin the water is warmer than the air
VerdunstungProzent	0.2	this % of the heat evaporates water; 0 = closed loop
MindestdruckKPa	10	below this the tower does not cool
VollerDruckKPa	80	full cooling from here
PumpeMolJeTakt	5000	maximum water flow through the tower
StromKW	5	power draw of pumps and controls
WaermeInLuftProzent	100	this % of the heat warms the air above the tower

5 Brennstabfabrik (fuel rod factory)

Key	Default	Meaning
UranerzJeStab	20	uranium ore per fuel rod
StahlJeStab	5	steel ingots per fuel rod
SekundenJeStab	60	production time per rod
StromKW	5	power draw while producing

6 Leitstand (control room desk)

Key	Default	Meaning
StromW	300	power draw of the desk
AlarmTonAn	on	main switch of all warning sounds

7 Strahlung (radiation)

Key	Default	Meaning
StrahlungAktiv	on	off = devices measure, but nobody takes damage
SchadenFaktor	1	1 = lethal after about 5 Sv above the threshold, 2 = twice as fast, 0 = count dose only
SchutzAnzugProzent	50	protection of a normal space suit with closed helmet
DosisSchwelleMSv	250	no damage up to this dose
ErholungMSvJeStunde	20	dose the body recovers per hour, 0 = never
WandDaempfungProzent	50	this % is kept out by each wall, 0 = off
StabMSvJeStunde	2000	dose rate of a freshly spent rod at 1 m
AbklingStunden	4	cooling time of spent rods in real-time hours
FassMSvJeStunde	40	dose rate of a fresh barrel at 1 m
FassHalbwertszeitStunden	48	half-life of the nuclear waste

8 Kernschmelze (meltdown)

Key	Default	Meaning
ExplosionAktiv	on	meltdown with an explosion
ExplosionStaerke	60	damage at the centre; radius = strength / 5 m, 3 to 25 m
ZoneRadiusM	10	radius of the contaminated zone
ZoneMSvJeStunde	100000	dose rate at the centre of the zone (100000 = 100 Sv/h)
ZoneAbklingStunden	3	time constant of the zone: 37% after this time, 5% after three times
RauchMinuten	30	how long smoke and steam rise from the wreck

9 Entsorgung (disposal)

Key	Default	Meaning
BunkerAbschirmungProzent	99.99	bunker shielding with the door closed
BunkerTuerOffenProzent	25	this % escapes with the door open
BunkerStromW	50	power draw of the bunker
RecyclerStaebe	3	spent rods per cycle
RecyclerNeueStaebe	1	new rods per cycle
RecyclerFaesser	1	barrels per cycle
RecyclerSekunden	120	duration of one cycle
RecyclerStromKW	20	power draw of the reprocessing plant
MonitorGrenzeMSv	0.5	alarm limit of newly built radiation monitors
MonitorStromW	20	power draw of the radiation monitor

10 Toene (sounds)

Key	Default	Meaning
TonVorwarnung	LogicError	pre-warning sound
TonAlarm	Alarm2	horn on the control room desk
TonNotabschaltung	Alarm7	scram sound
TonKernschmelze	Alarm10	siren on core damage
TonStoerung	Error	fault tone of turbine and cooling tower
TonLautstaerkeProzent	100	volume of all warning sounds

Valid sounds are speaker sounds such as Alarm2 to Alarm12, Danger, Warning, or game sounds such as LogicError and Error. Empty = off.

11 Strahlenschutz (radiation protection)

Key	Default	Meaning
SchutzStrahlenanzugOhneHelmProzent	75	radiation suit with closed game helmet
SchutzStrahlenanzugProzent	95	radiation suit with closed radiation helmet
EinatmenFaktor	1	extra internal dose when inhaling dust, 1 = as much as from outside, 0 = off
GeigerAlarmMSvJeStunde	100	from here the Geiger counter beeps loudly, 0 = never
MelderGrenzeMSv	0.5	alarm limit of newly built radiation detectors
MelderStromW	5	power draw of a radiation detector

Multiplayer#

New devices and items: the server and all players need the mod. The server does the calculations – reactor, turbine, cooling tower, radiation, dose, damage and zones. The players receive the display values, the radiation values every 2 s. The server's settings apply. Zones and doses are stored in the save. See Multiplayer.

Known limitations#

• At 280 °C the pressure limit is 1666 kPa, even if DampfHoechstKPa is set higher. More pressure would make the steam condense in the pipe.
• Reactor and turbine have to be on the same steam pipe network. The pipe alone can't carry enough steam at full power; the turbine draws it from the reactor's drum.
• Steam condenses in an uninsulated main steam pipe. The turbine drains the water and reports "Water in steam pipe (insulate)".
• The cooling tower needs outside air of at least 10 kPa that is colder than the water. It does not cool on Vulcan or Venus, and in a room it heats the room up.
• The control room desk's displays only show the first reactor, the first turbine and the first cooling tower. The buttons act on all of them.
• A single game cable or fuse in the 1 MW network limits the turbine.
• At most 300 lines of sight per second are calculated with walls. With very many players, devices and sources the rest is calculated without walls, so the radiation comes out rather too high.
• A melted reactor stays off for good. akw reset restores it.

Troubleshooting#

Display text / symptom	Cause	Fix
No feedwater pipe	no liquid pipe on the feedwater connection	connect a liquid pipe at the back of the reactor and link it to the turbine's condensate
No main steam pipe	no gas pipe on the main steam connection	connect a gas pipe at the back of the reactor
Feedwater low / No feedwater!	too little water in the feed loop, often after venting	top up water; check the turbine's condensate pipe
No power - pump stopped!	reactor without power	connect power; to start up there must already be power in the network
Relief valve venting	steam is not being taken: turbine off, tripped, valve closed	check the turbine, set the reactor to AUTO
Steam pressure high	drum above 92% of the pressure limit	raise the load or insert control rods, better use AUTO
Rod x over 90% burnt	rod almost empty	prepare a rod change
No fuel rods	channels empty	insert rods through the fuel hatch
Scram active (ACK to reset)	scram triggered	let it cool below 650 K, then ACK on the control room desk or main switch off and on
AUTO won't switch on	scram active, hatch open or main switch OFF	reset first or close the hatch
Fuel hatch won't open	control rods not fully inserted or fission power above 2%	shut the reactor down and wait; after a meltdown the hatch is jammed
Turbine: TRIPPED	reason on the display: condenser too hot (above 90 °C), no cooling water or manual	check the cooling loop and the tower, then RESET or ACK; pressed too early, the turbine starts by itself as soon as possible
Factory ejects the steel again	steel sheets instead of steel ingots, or a version before 1.0.2	load Ingot (Steel), update the mod
Condenser warm	cooling water too warm or too little	check the cooling tower, top up cooling water
No cooling water at the condenser	cooling water inlet empty or no pipe	connect and fill the cooling loop
Condensate pipe full	no room left in the condensate pipe	less water in the feed loop or more pipe
Turbine only supplies 4.75 kW, 95 kW or 475 kW	game cable or fuse in the network	use Extreme Cable or Power Cable+ throughout, separate consumers with a transformer
Bypass open	the network takes less than the reactor supplies	normal on load rejection; AUTO powers the reactor down
Water in steam pipe (insulate)	steam condenses in the pipe	lay an insulated gas pipe
Cooling tower: thin air	outside pressure below 10 kPa	put the tower where there is an atmosphere
Cooling tower indoors - heats the room!	the tower stands in a room	move the tower outdoors
Outside air too warm	air warmer than the cooling water	the tower does not cool on hot planets
Cooling water evaporating, empty in …	evaporation in the tower	add make-up water to the warm water pipe
Cooling tower OFF while turbine runs	the tower's main switch is off	switch the tower on
Control room desk: No reactor on the data network	data cable missing	put the desk and the plant parts on one data network
Control room desk: Vacuum - sounds muted	no air pressure at the desk	normal; nothing can be heard in vacuum
Factory: WAITING FOR MATERIAL	less than 20 uranium ore or 5 steel in store	add ore and steel
Factory or reprocessing plant: OUTPUT BLOCKED	output tray or chute occupied	clear the output
Reprocessing plant: WAITING FOR RODS	less than 3 rods in stock	add rods
Bunker: FULL	all 12 slots occupied	recycle decayed rods or build a second bunker
Recycler throws out rods or barrels	it does not take spent rods or barrels	put them into the bunker or the reprocessing plant
Save won't load	mod missing from the pack	see Mod packs