[0.14] Implement Nuclear Fusion Power

[MiniHerc]

Kovarex in the latest dev blog said he welcomes input for what to do with nuclear power in 0.14 and this is my suggestion.

I play a LOT of heavily modded minecraft and one of my favorite power producers is the Mekanism fusion reactor. It is very much an end game power source requiring an extensive production chain for the fuel but once set up it is self sustaining from nothing more than brine (sea water). It uses two fuels, Deuterium and Tritium.

This is the way that Mekanism handles these two fuel sources: Deuterium is produced from special water pumps filtering heavy water from ordinary water, then electrolyzed into Oxygen, which is discarded, and Deuterium. For Tritium, lithium is extracted from brine (sea water), then converted into a gas and run through 'Solar Neutron Activator plants' to convert into tritium.

Finally, the actual Mekanism fusion reactor requires an enormous power investment in the form of a tremendous laser pulse into a 'hohlraum' filled with a Deuterium-Tritium mixture for the fusion reaction initiation. Once the fusion reaction is self sustaining though, you have power forever.

In Mekanism, the fusion reactor automagically converts the fusion reaction into power with an option for steam production which I've never used, but I think for Factorio's purposes, it would be appropriate for the reactor to produce a humongous amount of steam which is then fed into standard steam engines.

Obviously, the Factorio team would probably want to do a few things differently and since the Tritium production is iffy (solar neutron activators? ha (I don't actually know much about how this might work in real life)), they may want to go with straight deuterium fuel.

TLDR: Since we already have fusion reactors for power armor, a logical progression is fusion reactor structures for powering our base, with appropriate fuel chains and power generation.

[Versepelles]

I would like to see nuclear power take on a form similar to Yuoki's Engines, developed by fatmice, where temperature and liquid inputs and outputs have to be carefully controlled.

[vipm23]

For tritium: The usual production method is neutron activation of lithium. This, unlike most nuclear reactions we use, doesn't require the neutron to be of any particular energy.
Usually this is done in a fission reactor, with a lithium jacket around the reactor core to capture stray neutrons.

Deuterium-tritium fusion produces one helium-4 atom, and one 14.1 MeV 'fast' neutron.
The neutron isn't needed for the reaction, and usually escapes. This is annoying, as it's radiation that's hard to shield against and renders what it hits more radioactive over time.
However, it does mean we can breed tritium from a lithium jacket.

This gives you two different production methods for tritium-from fission reactors, for an early source to jump start from, and fusion reactors.

Tritium can be used in thermonuclear weapons, and also self powered lighting, so we have at least three different uses for it.

[cellular]

Very high-level/conceptual idea: maybe nuclear power could be implemented in such a way as to force you to use the circuit network and combinators? For example, maybe the player should need to add specific materials at specific times, and adding the wrong material at the wrong time causes A Bad Problem. It seems like the one aspect of the game that nothing really forces you to get to grips with so far. Red science teaches you the basics, green science teaches you large-scale automation, blue science teaches you about fluids and dealing with complexity, and purple science teaches you about killing biters, but nothing really teaches you about combinators.

(Actually, there'd probably be some mileage in a mod adding more processes along those lines...)

[Ratzap]

A lot of it depends on how willing the devs are to add more ore types or basic resources. You can't fuel fission reactors with iron or copper but you could work water based fusion into the game as it stands.

I'd certainly expect to see large scale fusion power before the personal reactor in the tech tree as well.

If the devs are willing they could add uranium or 'radioactives' as an ore type and work in fission from that.

Bear in mind though that Factorio as a game doesn't do mistakes or accidents. Trains don't randomly derail, pipes don't burst etc so don't expect a reactor to have 'bad things' happen if condition A. It's not how the game is built (but that's not to say it couldn't be changed to do so).

[MiniHerc]

Deuterium-tritium fusion produces one helium-4 atom, and one 14.1 MeV 'fast' neutron.
The neutron isn't needed for the reaction, and usually escapes. This is annoying, as it's radiation that's hard to shield against and renders what it hits more radioactive over time.
However, it does mean we can breed tritium from a lithium jacket.

If I'm reading this correctly, you'll still need a fission plant for tritium production since a fusion plant won't produce enough tritium to sustain itself.

So what, we need both fission plants and fusion plants? Fission plant for tritium then fusion for the real power.

[vipm23]

If I'm reading this correctly, you'll still need a fission plant for tritium production since a fusion plant won't produce enough tritium to sustain itself.

So what, we need both fission plants and fusion plants? Fission plant for tritium then fusion for the real power.

The fusion reactors we have right now are strictly experimental and not practical for producing power. None of them do lithium breeding, so the neutrons escape/get absorbed by reactor material.
ITER will be testing lithium breeding as part of it's D-T fusion experiments.

The breeding reaction is one neutron and one lithium-6 atom produces one tritium atom-3 and one helium-4 atom.
In theory, if you captured every neutron and didn't leak any tritium, you can make exactly enough to keep up with demand.

In practice, you'll probably need a fission plant or a particle accelerator to generate excess tritium, yes. (Accelerators can produce a neutron beam by firing protons into a tungsten target.)

[cellular]

A lot of it depends on how willing the devs are to add more ore types or basic resources. You can't fuel fission reactors with iron or copper but you could work water based fusion into the game as it stands.

I'd certainly expect to see large scale fusion power before the personal reactor in the tech tree as well.

If the devs are willing they could add uranium or 'radioactives' as an ore type and work in fission from that.

Bear in mind though that Factorio as a game doesn't do mistakes or accidents. Trains don't randomly derail, pipes don't burst etc so don't expect a reactor to have 'bad things' happen if condition A. It's not how the game is built (but that's not to say it couldn't be changed to do so).

Factorio definitely does mistakes with serious consequences. Trains can destroy each other and you if they're set up incorrectly, you can run yourself out of resources, and you can cause brownouts that leave you defenseless against the biters. A reactor blowing up if you feed it wrongly feels compatible with that ethos. What Factorio doesn't do is random disasters, like your examples of trains derailing or pipes bursting. If meltdowns happen, they definitely shouldn't be random.

e: One alternative to adding an ore for uranium would be to refine it from stone at a suitably unfavourable rate. Not the most realistic thing in the world, but at least uranium does occur in most rock so it's not as bad as (e.g.) the recipe for circuits using iron. And it would give stone another use in the late game.