[0.14] Nuclear power: use thorium instead of uranium

[Homusubi]

I heard that the Factorio team were looking for ideas on how to deal with nuclear power. Here's my 2.42 koruna on the subject.

It makes more sense for Factorio nuclear power to use thorium (in case any readers don't know, that's element number 90, two places behind uranium on the table) instead of uranium as the radioactive base for nuclear power. Here are the reasons why:

1. Thorium is significantly more abundant than uranium (because of its half-life, implying that the situation would be the same on any planet), making it more likely that someone running around an unknown area would find a thorium deposit than a uranium deposit.
2. Naturally-occurring thorium metal does not require enrichment to be used in power stations, whereas naturally-occurring uranium metal does, making thorium require one fewer specialised machine.
3. It is likely that the major reason why Earth nuclear power is uranium-based is because the initial research into nuclear power was done during the start of the Cold War when the US also wanted an excuse to make more nuclear weapons (which can be made as a byproduct of uranium power but not as a byproduct of thorium power). Considering the Factorio protagonist doesn't want to make a nuclear bomb (unless the biters get really bad I suppose...), thorium would be a more likely source of from-scratch nuclear power given the other reasons outlined. (Google "Alvin Weinberg" and/or "Molten Salt Reactor Project"...)

[hitzu]

1) In the game developers choose the scarcity of the resource for better and fun gameplay. Not for realism.

2) This is anti-gameplay. Players want challenge, not an easy-peasy yellow brick path.

3) There is no US and USSR on this planet, and actually players want nuclear weapon to deal with biters.

I know just one agrument for thorium based reactors — dealing with fluids. That could've been interesting if the whole fluid mechanics would be interesting and visual on the first place. And we have to deal with fluids in uraniun reactor anyway.

But the main thing is that this in-game nuclear power shouldn't be realistic at all, it should be fun and interesting, it should provide challenge and the moments of making decisions whatever the fuel it would be based on, be it an uranium, thorium, tiberium, unobtanium or bubblegumium.

[Fushigidane]

1. Thorium isn't fissile, it requires a breeder reactor to use which is more complicated to construct. You would also need to create some neutron source start the reactor which either requires a neutron generator with all the complexity that brings or enriched uranium.

2. Uranium doesn't require enrichment to be used in power stations. A heavy water reactor (like CANDU) is capable of using natural uranium. Uranium like thorium can also be used in breeder reactors and probably more easily as well because of better neutron economy.

3. Considering that the game takes place on another planet it would actually be rather weird if the ratio of U-235 to U-238 in natural uranium would be the exactly the same as on this planet. It would be perfectly reasonable to have up to 10 times higher U-235 ratio if that would be good from a gameplay perspective.

[Homusubi]

2) This is anti-gameplay. Players want challenge, not an easy-peasy yellow brick path.

Well, the whole process is made harder by how the ore is treated (this applies to both thorium and uranium): it has to be reacted with sulphuric acid (which is conveniently already in Factorio) to separate the useful product. It would be made even more complicated if hot H2SO4 was specified, thus requiring an initial coal system for heating (afterwards, water could be heated in the reactor). You can't just "smelt" uranium or thorium ore.

3) There is no US and USSR on this planet, and actually players want nuclear weapon to deal with biters.

...that would be extremely counterproductive, given that a nuclear weapon aimed at a biter nest would also destroy any factory buildings even remotely near it and render the surrounding area completely useless.

1. Thorium isn't fissile, it requires a breeder reactor to use which is more complicated to construct. You would also need to create some neutron source start the reactor which either requires a neutron generator with all the complexity that brings or enriched uranium.

2. Uranium doesn't require enrichment to be used in power stations. A heavy water reactor (like CANDU) is capable of using natural uranium. Uranium like thorium can also be used in breeder reactors and probably more easily as well because of better neutron economy.

Wait, so the first point is that breeder reactors wouldn't work in Factorio because they require a neutron source, but the second point is advocating uranium breeders in Factorio? (P.S. Never trust a uranium fast breeder reactor!)

As for CANDU and the like, you'd then have to include a heavy water factory (or however it is that they turn bonded H-1 into H-2), so it's no better from a Factorio perspective than enriching uranium.

3. Considering that the game takes place on another planet it would actually be rather weird if the ratio of U-235 to U-238 in natural uranium would be the exactly the same as on this planet. It would be perfectly reasonable to have up to 10 times higher U-235 ratio if that would be good from a gameplay perspective.

Half-lives don't depend on which planet the sample in question is from. There's nothing special about Earth that made the U-235/U-238 ratio what it is today, it's just because of the half-lives of the isotopes. And anyway, if we're talking gameplay-related science tweaks, then saying that the planet is bombarded by low levels of neutron radiation (it only takes one external neutron of the right energy to start a thorium reactor iirc) is as excusable as saying that the ratio of uranium isotopes is different for some weird reason.

[Klonan]

The choice on which specific form of nuclear energy the game will have will be based on gameplay over real world practicalities, and thorium as well as uranium processes are still being considered

[TheDagmaar]

[Gertibrumm]

maybe it should be possible to return liquids into water to create these nasty green swamps.
That way we could deal with unwanted radioactive waste and create natural biter barriers.
also biter mutants

[Fushigidane]

Wait, so the first point is that breeder reactors wouldn't work in Factorio because they require a neutron source, but the second point is advocating uranium breeders in Factorio? (P.S. Never trust a uranium fast breeder reactor!)

As for CANDU and the like, you'd then have to include a heavy water factory (or however it is that they turn bonded H-1 into H-2), so it's no better from a Factorio perspective than enriching uranium.

I was just countering your argument for thorium by saying you can do the same thing with uranium. The only advantage thorium brings is that it's more abundant but that is pretty meaningless in a Factorio context.

The heavy water approach would probably be the simplest realistic option as far as adding new stuff to the game and works fine if enrichment is a problem from a gameplay perspective.

Half-lives don't depend on which planet the sample in question is from. There's nothing special about Earth that made the U-235/U-238 ratio what it is today, it's just because of the half-lives of the isotopes. And anyway, if we're talking gameplay-related science tweaks, then saying that the planet is bombarded by low levels of neutron radiation (it only takes one external neutron of the right energy to start a thorium reactor iirc) is as excusable as saying that the ratio of uranium isotopes is different for some weird reason.

The ratio of U-235 to U-238 depends on the age of the solar system. There is no reason the Factorio solar system has to be exactly as old as our solar system.

A thorium reactor shouldn't need any external neutrons because it's loaded with a fissile material and not just pure thorium. With pure thorium less than 3% of the neutrons will cause fissions and for each fission you get less than 2.5 neutrons so it's kind of impossible to get a sustained chain reaction started.

[bobucles]

The name of the material isn't important. It could be "crystal-bug-onium" and still do the same thing. In fact it is detrimental to thinking of third tier power in such a narrow minded way as being strictly a "nuclear" thing. The important details are GAME MECHANICS. The player has to contend with what resources they initially need, what factory components they use to feed the energy generator, what logistic systems bind the resources together, and what risks are involved in using it.

At the end game the player has access to all of the game's tools. Consider the possibility RESTRICTING the player's tools to provide third tier power. For example maybe a high energy component can't be moved by belt. It just pops and destroys the belt instead. Pipes are always a tough puzzle to solve, especially for long distance fluid travel.. If a player is forced to use only rail systems, then they have to rethink their way of moving materials around and can't just botspam it.

[OdinYggd]

1. Thorium isn't fissile, it requires a breeder reactor to use which is more complicated to construct. You would also need to create some neutron source start the reactor which either requires a neutron generator with all the complexity that brings or enriched uranium.

Half life is a thing though, some of the nuclei will spontaneously decay and give off neutrons that can initiate the chain reaction. Plus there will always be impurities in the fuel, coolant, and core structure that can provide the necessary initiation. In practice though initiators of known radioactive intensity are often placed in a reactor core just to ensure that it starts up in a timely manner.

2. Uranium doesn't require enrichment to be used in power stations. A heavy water reactor (like CANDU) is capable of using natural uranium. Uranium like thorium can also be used in breeder reactors and probably more easily as well because of better neutron economy.

While there are reactor geometries to exist that can use natural uranium, they don't have a lot of flexibility in their neutron economy and often have to have some enriched uranium in them to make sure they are reactive enough to operate properly. A breeder reactor is only necessary if you are trying to consume an isotope that does not normally chain reaction, these throw away some neutrons to resonant capture in order to breed Pu-239 and U-235 from U-238 and U-233.

Thorium offers the ability to run natural fuel with less preparation required, and can also make atomic weapons if you wanted it to. We just didn't bother developing such devices because plutonium does the job so nicely.

3. Considering that the game takes place on another planet it would actually be rather weird if the ratio of U-235 to U-238 in natural uranium would be the exactly the same as on this planet. It would be perfectly reasonable to have up to 10 times higher U-235 ratio if that would be good from a gameplay perspective.

That ratio would be governed by the planet's age more than anything else. It could be exactly the same, or it could show the effects of a few million years more or less half life.

[Fushigidane]

Half life is a thing though, some of the nuclei will spontaneously decay and give off neutrons that can initiate the chain reaction. Plus there will always be impurities in the fuel, coolant, and core structure that can provide the necessary initiation. In practice though initiators of known radioactive intensity are often placed in a reactor core just to ensure that it starts up in a timely manner.

The definition of a fissile material is that it can sustain a chain reaction. In the case of thorium less than 3% of the neutrons will be able to cause fission, good luck sustaining a chain reaction with that.

While there are reactor geometries to exist that can use natural uranium, they don't have a lot of flexibility in their neutron economy and often have to have some enriched uranium in them to make sure they are reactive enough to operate properly. A breeder reactor is only necessary if you are trying to consume an isotope that does not normally chain reaction, these throw away some neutrons to resonant capture in order to breed Pu-239 and U-235 from U-238 and U-233.

Thorium offers the ability to run natural fuel with less preparation required, and can also make atomic weapons if you wanted it to. We just didn't bother developing such devices because plutonium does the job so nicely.

Heavy water reactors are more flexible than light water reactors in their neutron economy because the water eats up much fewer neutrons. Thorium again won't work unless you add something fissile to the fuel. Once you have become able to start breeding fuel you can easily get more fuel but you have to get to that point first.

That ratio would be governed by the planet's age more than anything else. It could be exactly the same, or it could show the effects of a few million years more or less half life.

Would it be unreasonable for the planet to be a billion or two years younger than Earth?

[mcwaffles2003]

I personally think including thorium would be a great idea. creating a complex reactor to handle this system would be great.
first you would harvest Th
Th would be reacted with F to make a Th salt
the ThF6 salt would have to be melted and combined with molten LiF and BeF2
you would need to create a neutron source to turn Th-232 into Pa-233 initially
Pa-233 would have a half life constantly making U-233 (make Pa-233 turn into something like "activated Pa-233") which uses a chem plant to separate into Pa-233 again and U-233
U-233 would have to be put into a graphite lined container (make graphite from carbon) make a new builing for doing all this named "Th reactor""
Th-232 would be held in a container surrounding the U-233 container constantly capturing neutrons making Pa-233 (maybe just have Th-233 in the same reactor and count it all as one)
meanwhile fission products could be generated called "fission products" which would get separated out and those could be sent to another thing similar to the crystalizers in angels mod where random goodies are made

[Shaymes]

i have some different idea, just call it "Factorium" ist a new element that can be used in powergeneration and it glows orange instead of green
i just think about "Avatar travel to Pandora"

(maybe not orange becouse copper)

[Syrchalis]

As a game designer, I can only repeat the meme up there:

Why not both?

If there is distinct and interesting advantages and disadvantages to both, they would make great additions to the game.

Uranium could be used as a less efficient "low tech" variant with the upside of being useful for weaponry as well. While Thorium could be used as high-end version, which requires a lot of effort to get working, but then surpasses Uranium in pure energy-aspects with the additional downside of being not usable for weaponry.

In other words: Uranium = relatively easy energy, also useful for weaponry. Thorium = hard to set up, but ultimate energy source, no weaponry application.