Full Operating Guide (Principles, Startup, Shutdown)

This guide goes through the operating principles of a pressurized water reactor (PWR), how the 3 fluid loops combine, what adjustment drives what value, then goes into how to start-up and shut-down the power plant.

Intro, contact information

Join the Nucleares Discord to communicate with the developer of the game and get help with things:
https://discord.gg/pg55hEqrwW

You will also find me there under the nick "Wolfhound", any feedback to this guide is welcome.

Basic Operating Principles

Basic schema of the power plant in use:

In-Game schema

Important note: At game start, you only have 1 primary and secondary circuit, the one in use is nr. 3!

Three Fluid Circuits

There are 3 separate fluid circuits, and 3 points where heat is transferred:
1: In the reactor core, pressurized water is heated up by nuclear fission
1: The primary circuit of pressurized water transfers the heat from the reactor to the steam generator, driven by the reactor coolant pump / coolant flow speed (RED in both schemas above)

1+2: In the steam generator, the heat from the primary circuit is used to boil water from the secondary circuit into steam

2: The secondary circuit takes the steam from the steam generator through the turbines (which use the energy in the steam to turn the electricity generator) - and finally to the condenser, from where the condensed water then flows back into the steam generator (Turquoise in in-game schema)
This is driven by the condensate pump / condenser flow speed
2+3: In the condenser, the steam is cooled down and condensed back into water
3: The condenser is cooled by a tertiary circuit, releasing the excess energy as steam in the cooling tower. This circuit flow is driven by the circulating pump / condenser cooling flow speed (Blue in in-game schema)

Reactor Core: Internal temperature and control rods

The internal reactor temperature should be 360°C according to the info in-game. This is controlled by 2 factors:
- Control rod insertion percentage: The higher this percentage (the more % of the control rods are inserted into the reactor core), the lower the temperature in the core will be, all other things being equal
- Primary coolant pump / coolant flow: The higher the coolant flow, the lower the core temperature will get, as more heat is transferred from the core to the steam generator

Pressurizer

The pressurizer is a pressure vessel filled with pressurized water from the primary cycle, used to keep that water pressure at a constant level, ideally at 160bar. To raise the pressure, we can use the heater, to lower it, we can use the cooling valve. Closely monitor the pressure whenever you use any of the two and only use cooling when really necessary. The pressure will drop over time naturally, and using the cooling valve (which sprays water into the pressurizer) can help to decrease the pressure additionally.

Steam Generator

The steam generator temperature and pressure are directly driven by the Primary Coolant Pump / coolant flow. The higher this is, the more heat is transferred from the core to the steam generator, thus increasing temperature. As more water boils off, pressure rises.

The water level in the steam generator is regulated by the Secondary Condensate Pump / condenser flow. This regulates how much water from the condenser gets back into the steam generator. Note that this will also lower the temperature in the steam generator, but don't use it to regulate steam gen temperature! Use it exclusively to ensure sufficient water level.

Condenser

Condenser temperature is controlled by the condenser circulating pump / condenser cooling flow speed

The condenser water level should always be at 100% - if it's lower, use the "condenser circuit" load pump to pump water from the river/regulating basin into the secondary circuit.

If it's higher, an automatic vent valve will open and release steam from the condenser, also lowering the temperature noticeably. This can be used in a pinch, if condenser temperature gets too high. This is true as of version (0.2.07.061) but may be changed to a manual valve in the future.

Start-up

General Tips

- To see values of gauges in more detail and judge the change (if increasing or decreasing), hold right mouse button and look at the gauge
- Don't go increasing values wildly unless something goes horribly wrong. Small values by 1-2% on pumps and 0.1-2% on control rods and close monitoring of values over time ensures success

Preparing the power plant, starting pumps

1: Activate all stations in the control room (activate switches forward)
2: Start the pumps on all 3 circuits:
- Reactor coolant pump / coolant flow speed to 50% (medium), start pump 3
- Condensate pump (condenser flow speed) to 25% (low), do NOT start pump yet
- Condenser circulating pump (condenser cooling flow speed) to 75% and start
3: Fill up the secondary circuit:
- In the coolant section, cooling circuit, condenser loop, switch to "load"
- Closely monitor the condenser level, stop the load t about 85% (it needs time to run down)and fill it up to 10'000L (100 on the gauge)

4: Preheat the pressurizer
- With heating power on high, switch the heaters on
- Closely monitor the pressure, when it reaches 160bar, switch the heaters off
- Set heating power to low for future use

5: Start-up the reactor
- In the middle of the control room, set the operating mode to nominal
- In the fuel section, press the green "insert in core" button
- Set the control rods to between 90% and 98% (the more impatient you are, the higher, but the more attention you have to give, not to overheat the reactor core and create tchernobyl v2.0)

8: Ensure steam genreator water level
- As steam generator temperature rises, observe the water level (nr 3), start the condensate pump (condenser flow speed) and raise the speed as required to keep a green level
- As reactor core temperature rises, observe and when it reaches 300°C raise control rod % to 98.5%, then fine-tune from there (stabilization)

7: Connect to the grid
- As the turbo-generator set starts producing power, connect it to the electricity network
- Stop the internal supply generator 01, and set it to automatic

Stabilization

Generally speaking, with the starting values from the start-up, the only value you need to change is condensate pump / condenser flow speed to ensure sufficient steam generator water level as temperature rises.

Closely observe the following values and adjust them as required:

- Reactor core internal temperature should rise and stabilize around 360°C
-> If too high, increase control rod %
-> If too low, decrease control rod %
Both should only be done in small steps with the +/- buttons, at a maximum of 0.2% at a time, then closely monitor internal temperature

- Steam generator temperature and pressure should rise, and with that, turbine generator output should rise
- Do not try to control the steam generator temperature, just control the water level (nr. 3).
If steam generator water level decreases, increase the condensate pump / condenser flow speed slightly, by 1 or 2% at a time

Let the reactor slowly start up and stabilize before you change things. Patience is key in this game, all the systems are interlinked with each other and it takes very minor adjustments to change values, but it takes time for them to change.

When the reactor is stable over several in-game hours, take the staircase up to the internal supply generator and refill it with fuel

Values that work for me (v0.2.07.061):
Control Rods: 98.5%
Reactor coolant pump / coolant flow speed: 50%
Condensate pump / condenser flow speed: 51%
Circulating pump / condenser cooling flow speed: 75%

To increase produced power, increase reactor coolant pump / coolant flow speed slowly, adjusting the control rods (lower %) to keep reactor core internal temperature up at 360°, closely observe steam generator water level and adjust as indicated above.

Shutdown

To shutdown, we go everything from start-up, just in reverse, RIGHT? .. right?

No, we let the whole power plant run while we stop the nuclear reactor, using the remaining heat to produce power while we cool everything down.

Assuming we have a stable running reactor, these are the steps:

- Ensure the internal supply generator 01 is set to automatic
- Set control rods to 100%
- As things cool down, bring down the pump flow speeds, until you can finally shut them off completely.
- When steam generator temperature falls below 140°C, disconnect from the network (power generatoin will fall off soon)
To minimize time running the internal generator, you want to keep the reactor coolant pump / coolant flow speed at a medium setting, and slowly adjust the condensate pump / condenser flow speed just to keep steam generator fluid level in the green. As condenser temperature falls, you can lower the circulating pump / condenser cooling flow speed setting as well.

[[RSL] Klaus_Ferrano]

this need a update to the curent version

[Shabazza]

The original one is probably written via GPT.

This here is simply outdated, as the loops are inconsistently called A, B, C now in game, while some places still call it 1,2,3 in the control room.
So back in the days, this guide was labeling it correctly.

[ioudas]

This is written in the same confusing English as the official manual.

e.g.:
"Important note: At game start, you only have 1 primary and secondary circuit, the one in use is nr. 3!"

Written under a picture that has no "nr.3" written on it anywhere.

And then "bullet points" using the same numbers: "1: 1: 1+2:". Is this intentionally confusing?

[`Kayne]

* I forgot to add to my comment that you're doing all that from the buttons directly around the synchrometer thingy-ma-jig

[`Kayne]

@arueshalae Close circuit breaker == connect generated power to grid, Open circuit breaker == disconnect generated power from grid

Use the two numeric screens to match left (your) values with right (grid) values. You can synchronise to the grid by adjusting the RPM higher or lower to increase / decrease YOUR frequency. Once the green LED is at the top, Undo the small adjustment you just made to re-sync

[Arueshalae]

Is this guide out of date? I don't see a Turbine Generator control panel. I see a much more complex Energy Generation panel.

[Doctor Lucy]

how can we fix the dry alarm on cir pumps

[tomas.v.georgiev]

I dont know for what is the vent valves?

[Kindmanathome]

idk just got the game

[supertobit]

how 2 change the fuel of the reactor ?