Portable fusion reactor [New recipe]

[TheBigZet]

Actual recipe for Portable fusion reactor needs only 250 Processing units.
Now, when we have nuclear power in game, so Portable reactor could be made of Nuclear reactor and some circuts etc.
What about that?

Have a nice day

[Koub]

[Koub] Moved to balancing.

[bobingabout]

I agree that the fusion reactor does seem out of place requiring only 250 processing units. (only? I know they're not cheap, and 250 is a fair sum, but it is still the only item type)

problem with nuclear fuel, is that's a fission process, not a fusion process.
The problem could be solved if you turn it into an RTG instead (Radio thermic generator. The radioactive source produces heat. A difference in heat from the inside to the outside produces an electric current.)

Also, old recipe used alien artifacts, I'm guessing the devs didn't really know what to do about the recipe when they removed alien artifacts from the game, then forgot to do anything with it.

[BlakeMW]

Rather than a RTG it could also be a straight up portable fission reactor. It's for mounting in some pretty beefy power armor after all. Russia has used sub-400kg reactors in satellites so it is entirely plausible - in fact on a planetary surface more viable since cooling is a lot easier. To power energy-hungry stuff like portable lasers a fission reactor is a lot more plausible than an RTG, as fission results in a much higher power density than alpha decay.

[Xeorm]

RTGs are a bad fit. Main reason they're loved is for simplicity - they work and don't have moving parts and are pretty decent in terms of power per mass and size when you can't use solar power. They'd be a terrible fit for body armor on a solar-rich planet like Factorio.

Fission reactors run hard into the minimum size problem. Can't reduce the size down too far or the reaction doesn't work. Best data I've seen says that a "portable" reactor producing enough energy for the suit would be around 400kg (~900lb). Seems a bit too heavy, and what's worse we know a lot about the science, so it tends to break my suspension of disbelief when the numbers are so out of whack.

Fusion reactors are therefore plausible because we haven't done enough research to figure them out yet. They could be good enough, and that's good for me. Given that they work on magic, the recipe using just blue circuits works fine, I think. If you wouldn't run into copyright issues I'd suggest the name "Arc Reactor" to make it even more of a magic power generation device.

Unless it's changed to be fission though, it shouldn't require any fission bits in the recipe. They're both nuclear power, but they're still very different processes.

[bobingabout]

As far as I know, there are only 2 methods to get energy out of radioactive material. And both of them extract it in the way of heat.

1. Heat boils water, creates steam, creates pressure, this is then run through some sort of steam engine or turbine.
2. RTG, this also works via heat.

If there is another method I don't know of, please let me know.

[BlakeMW]

As far as I know, there are only 2 methods to get energy out of radioactive material. And both of them extract it in the way of heat.

Here are three other ways:

A closed cycle gas turbine (using Brayton cycle) with a working fluid like helium or CO2 (https://en.wikipedia.org/wiki/Safe_Affo ... ion_Engine)
Stirling engine (https://ntrs.nasa.gov/archive/nasa/casi ... 017750.pdf)
Infrared photovoltics (not aware of serious investigation for use with fission reactor, but if you have hyper-efficient solar technology...)

Fission reactors run hard into the minimum size problem. Can't reduce the size down too far or the reaction doesn't work. Best data I've seen says that a "portable" reactor producing enough energy for the suit would be around 400kg (~900lb). Seems a bit too heavy, and what's worse we know a lot about the science, so it tends to break my suspension of disbelief when the numbers are so out of whack.

Though they would be a little bit heavy, they are quite compact - good power density. Considering how beefy the Power Armor II should rightfully be (it has resists comparable with a Tank!) I really can't see a problem with a 500kg power source. The weight could also be reduced by a lot if you have some magical handwavium shielding, like oh say energy shields, as magical shielding (emphasis on magical because stopping neutrons ain't easy!) could act as shielding, neutron reflector and moderator (by allowing more or less of the neutrons to escape, presumably directed out the back rather than towards the occupant of the armor).

There is also no plausible reason to believe a fusion reactor could be made smaller than a fission reactor especially with a technology level of factorio engineer which for the most part is "clanking replicator", but with the exception that Factorio engineer seems to know a simple way to make energy shields and energy weapons. Maybe the technology for energy shields and weapons would lend itself to a compact fusion reactor, that would be plausible, but as per above it'd also make for a fantastically compact fission reactor by replacing moderator and shielding.

[Xeorm]

As far as I know, there are only 2 methods to get energy out of radioactive material. And both of them extract it in the way of heat.

1. Heat boils water, creates steam, creates pressure, this is then run through some sort of steam engine or turbine.
2. RTG, this also works via heat.

If there is another method I don't know of, please let me know.

Currently, the first is most widely used, but thermocouples (what the RTG uses to actually turn the heat into energy) also function. There's research on more options, some that could potentially be promising.

https://en.wikipedia.org/wiki/Direct_en ... n_products would be one example.

[bobingabout]

A closed cycle gas turbine (using Brayton cycle) with a working fluid like helium or CO2

Main energy transfer out of the fuel is via Heat.(https://en.wikipedia.org/wiki/Safe_Affo ... ion_Engine)

Stirling engine (https://ntrs.nasa.gov/archive/nasa/casi ... 017750.pdf)

Also heat.

Infrared photovoltics (not aware of serious investigation for use with fission reactor, but if you have hyper-efficient solar technology...)

IR is also heat.


When I said "Does anyone know any other method", I meant one that doesn't use heat.

[BlakeMW]

I wouldn't say that using photovoltaics is heat in the traditional sense. Regardless of the exact wavelengths whether infrared, visible or ultraviolet photovoltaics work by photons knocking lose electrons which is why they are not regarded as heat engines. Infrared is not especially "hot", no moreso than visible light or ultraviolet, it just happens that infrared is invisible to the human eye and there tends to be an awful lot of it due to the blackbody radiation curve so it "feels hotter" and we can only sense it as heat, so if IR photovoltaics are using heat, then by the same definition all photovoltaics are using heat. It seems to me that if you wanted to harness the power of a nuclear reactor while discarding 100% of the thermal motion and thermal radiation you couldn't end up with a very efficient generator. (A Nuclear Lightbulb style reactor could run at such temperatures that most the thermal radiation is hard ultraviolet rather than infrared - I don't know if harnessing UV would feel less heaty than harnessing infrared)

[bobingabout]

I wouldn't say that using photovoltaics is heat in the traditional sense. Regardless of the exact wavelengths whether infrared, visible or ultraviolet photovoltaics work by photons knocking lose electrons which is why they are not regarded as heat engines.

Single block of text makes it hard to read.

But I guess you have a point, IR isn't necessarily heat. Make something hot enough, you do get visible light. I guess it's more of a disturbance in the electromagnetic spectrum (Caused by heat)

[BlakeMW]

By the way on the wiki page for U-235 there's a useful chart with an energy breakdown of a fission reaction, the most important thing is the total energy is 211.3MeV and the kinetic energy of the fission fragments is 169.1MeV. Basically the vast majority of the energy released by a nuclear fission IS thermal energy and only a small fraction of the remainder might be potentially harnessable (i.e. beta decay 6.5MeV - maybe something can be done with the charged particles). So if you want to get a useful fraction of the energy you have to harness the heat in some manner or another.