How exactly could people convert energy from miniature fusion reactor to electricity?

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How exactly could people convert energy from miniature fusion reactor to electricity?

Post by False Prophet » Thu Dec 12, 2019 4:18 am

Could a design based on boiling water or pressurized water nuclear reactors work on an 0079 MS? And if that is the case, would you need a concrete shell outside the Minovsky reactor? Would you need to fear thermal runaway? What about radioisotope thermoelectric generator?

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Re: How exactly could people convert energy from miniature fusion reactor to electricity?

Post by Seto Kaiba » Thu Dec 12, 2019 1:07 pm

False Prophet wrote:
Thu Dec 12, 2019 4:18 am
Could a design based on boiling water or pressurized water nuclear reactors work on an 0079 MS?
Based on what I've read, the answer would be yes... the generator systems Mobile Suits use to harness power from their Minovsky ultracompact fusion reactors are Rankine cycle turbine generators that are used to convert reaction heat into electricity, supported by Brayton cycle magnetohydrodynamic generators that pull energy directly from reaction products.


False Prophet wrote:
Thu Dec 12, 2019 4:18 am
And if that is the case, would you need a concrete shell outside the Minovsky reactor?
No. Concrete containment shells are a last-ditch safety measure for nuclear fission reactor. They're intended to prevent steam or other superheated gases that might be carrying particles of the reactor's radioisotope fuel from escaping into the atmosphere in the event of a reactor accident of sufficient severity to compromise every other safety measure protecting the reactor. This is necessary because the radioisotopes used as fuel in reactors have half-lives measured in tens of thousands or even hundreds of millions of years, which could have catastrophic consequences if fuel were to be released into the surrounding environment.

This isn't a problem for thermonuclear fusion reactors, since neither the fuel material nor the reaction products are radioactive material. Most of the reaction's energy is released as heat, most of the radiation produced is of types that can be blocked by a heavy sweater, and the levels of dangerous neutron radiation are negligible or at least not immediately dangerous. Minovsky reactors are using Deuterium and Helium-3 for fuel. Deuterium is a isotope of Hydrogen, which is a flammable gas and has to be stored under high pressure as a cryogenic liquid or gas, but otherwise isn't dangerous. Helium-3 is an isotope of Helium, an inert noble gas, which is also stored in liquid or gas form under high pressure, but is even safer to handle than Deuterium. If trace amounts of either escape into the atmosphere, the worst you'll get is your voice will temporarily get squeaky if concentrations of those gases get too high.

Contrary to much of popular fiction, fusion reactors DO NOT blow up when they're damaged. The loss of plasma containment kills the reaction stone dead almost immediately because the pressure of the containment is what keeps the reaction going. It's more or less impossible to turn a fusion reactor into a fusion bomb the way that's flogged to death in Victory Gundam.


False Prophet wrote:
Thu Dec 12, 2019 4:18 am
Would you need to fear thermal runaway?
Nope. Thermal runaways are a concern in fission reactors because the fuel is constantly decaying and emitting heat no matter what you do, and will continue to do so for millennia.

In a fusion reactor, the reaction stops as soon as you either shut off the fuel supply or you relax the containment field applying pressure to the fuel (be it magnetic, Minovsky particle, or gravitational).


False Prophet wrote:
Thu Dec 12, 2019 4:18 am
What about radioisotope thermoelectric generator?
Radioisotope thermoelectric generators are one specific application of thermoelectric generator technology. The RTG uses the decay of fission fuel (radioisotopes like plutonium) as a heat source and converts that heat directly into electricity via the Seebeck effect.

You can use thermoelectric generators to convert heat from any high heat source into electricity... including from a thermonuclear fusion reactor.

The Compact Thermonuclear Reactor - AKA "Fold Reactor" - in Macross uses thermoelectric generators as the main generator system to convert the heat from the fusion reaction into electricity and captures additional power from the plasma stream using a magnetohydrodynamic generator downstream from the reactor itself.
Last edited by Seto Kaiba on Thu Dec 12, 2019 5:23 pm, edited 1 time in total.
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Re: How exactly could people convert energy from miniature fusion reactor to electricity?

Post by Seto Kaiba » Thu Dec 12, 2019 2:02 pm

As you no doubt surmised from the above, the dangers of nuclear fission reactors are why no sane person would ever put a fission reactor into a vehicle like a Mobile Suit or fighter. If its reactor were ever damaged or destroyed, all of the highly dangerous radioisotope fuel would be released into the surrounding environment... leading to a expensive cleanup operation and lingering radioactive contamination of the area for millennia.

(This fact reflects rather poorly on the Cosmic Era, where ZAFT really WAS so unhinged that they put fission reactors into mobile weapons like the Justice and Freedom Gundams.)
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Re: How exactly could people convert energy from miniature fusion reactor to electricity?

Post by Seto Kaiba » Thu Dec 12, 2019 5:35 pm

Generators like steam turbines, MHD dynamos, and thermoelectric converters are far from the only ways to possibly extract energy from a thermonuclear fusion reaction... they're just the most conventional ones.

Alphavoltaics and Betavoltaics can capture alpha and beta particles and generate electricity from them using a semiconductor junction, similarly to photovoltaic solar panels capturing light and converting it directly to electricity.
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Re: How exactly could people convert energy from miniature fusion reactor to electricity?

Post by False Prophet » Sat Dec 14, 2019 7:12 am

Seto Kaiba wrote:
Thu Dec 12, 2019 5:35 pm
Generators like steam turbines, MHD dynamos, and thermoelectric converters are far from the only ways to possibly extract energy from a thermonuclear fusion reaction... they're just the most conventional ones.

Alphavoltaics and Betavoltaics can capture alpha and beta particles and generate electricity from them using a semiconductor junction, similarly to photovoltaic solar panels capturing light and converting it directly to electricity.
Say, if you go by Gundam's ultracompact fusion reactors, do we have a general idea of how much energy is in the form of light, and how much in the form of other electromagnetic radiation types? Could we built a system that could convert radiation from the entire electromagnetic spectrum (like Bremsstrahlung?), or doing that require so many types of energy converters that it becomes inefficient?

Also, how do mobile suit (or fusion nuclear plants) in general take care of the byproducts of the reaction? For example, how much do we really need helium again? And I heard that electrons in high-energy state (not yet plasma) can do considerable damage to semiconductors. Is it true?

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Re: How exactly could people convert energy from miniature fusion reactor to electricity?

Post by DragoMaster009 » Sat Dec 14, 2019 1:35 pm

Seto Kaiba wrote:
Thu Dec 12, 2019 2:02 pm
As you no doubt surmised from the above, the dangers of nuclear fission reactors are why no sane person would ever put a fission reactor into a vehicle like a Mobile Suit or fighter. If its reactor were ever damaged or destroyed, all of the highly dangerous radioisotope fuel would be released into the surrounding environment... leading to a expensive cleanup operation and lingering radioactive contamination of the area for millennia.

(This fact reflects rather poorly on the Cosmic Era, where ZAFT really WAS so unhinged that they put fission reactors into mobile weapons like the Justice and Freedom Gundams.)
I always thought that was because nobody in the Cosmic Era could figure out how to make a nuclear fusion reactor small enough to fit onto the average mobile suit?

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Re: How exactly could people convert energy from miniature fusion reactor to electricity?

Post by Seto Kaiba » Sat Dec 14, 2019 5:41 pm

False Prophet wrote:
Sat Dec 14, 2019 7:12 am
Say, if you go by Gundam's ultracompact fusion reactors, do we have a general idea of how much energy is in the form of light, and how much in the form of other electromagnetic radiation types?
In theory, very little... since the majority of any fusion reaction releases energy in the form of high-energy charged particles and the actual quantity of fuel reacting is very small. The fusion of Deuterium and Helium-3 produces an alpha particle (Helium-4 nucleus) and a high-energy proton. Most of the energy is in the form of charged particles.

The use of Minovsky particles (or rather, the natural i-fields they produce) is apparently key to improving the total systemic efficiency by reducing the amount of fuel not participating in the reaction and reducing the fuel which is taking part in side reactions (Deuterium-Deuterium fusion can produce free neutrons).


False Prophet wrote:
Sat Dec 14, 2019 7:12 am
Could we built a system that could convert radiation from the entire electromagnetic spectrum (like Bremsstrahlung?), or doing that require so many types of energy converters that it becomes inefficient?
Bremsstrahlung isn't a type of radiation, it's a radiation emission phenomena that can produce radiation in many different spectra.

Trying to capture and convert the entire electromagnetic spectrum into usable forms of energy would be a pretty wasteful endeavor... a lot of it just isn't particularly useful.


False Prophet wrote:
Sat Dec 14, 2019 7:12 am
Also, how do mobile suit (or fusion nuclear plants) in general take care of the byproducts of the reaction? For example, how much do we really need helium again? And I heard that electrons in high-energy state (not yet plasma) can do considerable damage to semiconductors. Is it true?
Depends on the reactor configuration and what the reactor is being used for.

Ordinarily, some reaction plasma that isn't actively being tapped for power generation is kept around to maintain the reactor temperature and pressure. Plasma that's drawn off the reactor for power generation or other uses is going to slowly cool down and will generally become an exhaust gas... though the quantity of exhaust will not be high because of the small amounts of fuel being fused at any given time. Sometimes, this exhaust plasma is used for other purposes.

For instance, the plasma produced by the fusion reactors aboard starships in Star Trek is used to generate power and is vented as exhaust through the ship's impulse engines where it's used to charge the impulse engine's subspace field coils that either propel the ship as a sort of low-powered warp drive for sublight speeds (on 24th century ships) or to cheat the ship's inertial mass down to the point that the plasma can accelerate the ship as rocket exhaust (on 23rd century ships).

On Macross's VFs and starships, the plasma from thermonuclear reactors is used to generate power and then is exhausted through the engines as a waste gas (in atmosphere) or as a propellant (for space maneuvering). This use of reaction plasma as a propellant means that VFs don't have to carry separate fuel tanks for its engines like a Mobile Suit does... at the expense of cutting their total operating time harshly by requiring significantly greater fuel consumption to produce enough plasma.
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Re: How exactly could people convert energy from miniature fusion reactor to electricity?

Post by False Prophet » Sun Dec 15, 2019 9:54 pm

Say, I recently read about how important economy of scale is to nuclear reactors, and why it is not a very profitable field for private companies and their proprietary component designs. Conversely, I wonder if the fusion reactors in UC are quite cheap because they are all mass-produced by Anaheim.

(Economy of scale really put a whole new perspective on mobile suits. For example, the reason that the dirt-poor Sleeves, with the assistance of the dirt-poor Republic of Zeon, could still afford the Geara Zulu--they are cheap. I even heard that the real full-spec Geara Zulu is more similar to the Guards Type, and not the watered-down mass-production models.)

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Re: How exactly could people convert energy from miniature fusion reactor to electricity?

Post by Seto Kaiba » Mon Dec 16, 2019 12:20 am

False Prophet wrote:
Sun Dec 15, 2019 9:54 pm
Say, I recently read about how important economy of scale is to nuclear reactors, and why it is not a very profitable field for private companies and their proprietary component designs.
Well, to be fair, a not-insignificant part of the cost of developing and constructing new nuclear power plants isn't in the development and construction of the reactor itself. It's in government certifications, inspections, and all of the various government-mandated safety requirements for the reactor and for the storage and disposal of spent fuel material. It's quite a substantial additional cost when you have to buy massive plots of land that are fenced off and need to have an armed security contingent at all times, and you have to build not just the reactors and generators but also the massive armored concrete containment domes capable of withstanding a catastrophic reactor failure from within as well as a suicidal ramming attack from a fully-loaded jumbo jet.

That adds a SIGNIFICANT amount of additional cost... never mind all the expense of getting your design certified and approved by the government to begin with.

Fusion reactors in sci-fi usually don't have to contend with most of that. Their fuels are inert or - at worst - flammable cryogenic gases that won't cause radioactive contamination if they leak into the environment. They're not capable of melting down, they can be shut off at a moment's notice by turning off the fuel flow, and contrary to popular fiction a fusion reactor can't be turned into a bomb. The fundamental difference in their operation means they're simply not a technology susceptible to the same nasty, expensive failure modes as modern nuclear reactors. Science fiction has taken it even further with applications that have special physics to contain the reaction that make them safer still by further preventing the emission of potentially hazardous radiation that was already mitigated by the choice of fuels.

When you don't have to jump through all those massive infrastructure-based safety hoops, developing and building a mass-produced reactor is a LOT easier.

(If you do some digging, you'll find records for a lot of cheaper early nuclear fission reactors that were cheaper because the government regulations and requirements didn't exist yet so things like the expensive concrete safety structure did not get built or they used designs with obvious flaws for test purposes.)


False Prophet wrote:
Sun Dec 15, 2019 9:54 pm
Conversely, I wonder if the fusion reactors in UC are quite cheap because they are all mass-produced by Anaheim.
It's because they don't need ninety percent of the safety features a modern nuclear fission reactor does, because they use fusion not fission, their fuel was deliberately chosen to minimize the potential to produce dangerous radiation, and the reactor itself uses a pinch technology (i-fields) that contains the radiation and heat of the reaction and does a lot to minimize side reactions that might produce harmful radiation, making them VASTLY safer to operate than even the best modern nuclear fission reactor.

(Like I said before, the dangers involved in just handling radioisotopes suitable for nuclear fission reactors is so unsafe that only a complete psychopath or drooling idiot would think of sticking fission reactors in something as explosion-prone as a Mobile Suit.)


False Prophet wrote:
Sun Dec 15, 2019 9:54 pm
(Economy of scale really put a whole new perspective on mobile suits. For example, the reason that the dirt-poor Sleeves, with the assistance of the dirt-poor Republic of Zeon, could still afford the Geara Zulu--they are cheap. I even heard that the real full-spec Geara Zulu is more similar to the Guards Type, and not the watered-down mass-production models.)
Economy of scale helps, sure, but a big part of what made it feasible to scale up production in the first place was that a Minovsky ultracompact fusion reactor is safer than a conventional fusion reactor and MUCH safer than a nuclear fission reactor. It's about as safe as any other military-grade power source. If a Minovsky reactor still needed expensive heat and radiation shielding to operate, they'd never have caught on.
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Re: How exactly could people convert energy from miniature fusion reactor to electricity?

Post by False Prophet » Mon Dec 16, 2019 3:31 am

I am all for nuclear power plants AND regulations at the same time. If anything, it helps sway the public's opinion of these plants, which had been low even before Fukushima in 2011--I heard that the people around Three Mile Island are still being paranoia about traces of radiation. The repression of activists and whistleblowers like Karen Silkwood surely didn't help, too.

(I wonder if Dr. Minovsky is a billionare for patterning his reactors, or did he pulled a Jonas Salk and made the design a free property.)

Anyway, the containment fields in fictional nuclear fusion reactor must be created first before the plasma, right? Does this mean these reactors have some kind of secondary generators/batteries to power the fields either during the entire operation, or just for a period before the reactors create energy?

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Re: How exactly could people convert energy from miniature fusion reactor to electricity?

Post by Seto Kaiba » Mon Dec 16, 2019 12:42 pm

False Prophet wrote:
Mon Dec 16, 2019 3:31 am
(I wonder if Dr. Minovsky is a billionare for patterning his reactors, or did he pulled a Jonas Salk and made the design a free property.)
Neither. Dr. Trenov Y. Minovsky's research was bankrolled by Anaheim Electronics on behalf of the Earth Federation Government. He was a researcher on Anaheim Electronics' payroll. That means anything he created while working for Anaheim Electronics belonged to Anaheim Electronics. Similarly, once he moved to Side 3 and began working in further developments for Zeonic on behalf of the Republic of Zeon (later the Principality of Zeon) the results of his work would have belonged to Zeonic. Minovsky's name would still have been on the publications, all the academic papers, etc., and he named the particle after himself, but the right to commercialize that discovery belongs to his employers because they paid for his research.

(Contrasting example... in Macross, almost all early advances in overtechnology were made by a multinational research and development coop called OTEC that the United Nations set up to avoid having any one nation attempt to monopolize overtechnology. The Earth Unification Government that replaced the United Nations instituted laws that mandated sharing technological advances for similar reasons. It wasn't until well after the First Space War that tech giants started to independently research new technologies and patent those advances for profit.)


False Prophet wrote:
Mon Dec 16, 2019 3:31 am
Anyway, the containment fields in fictional nuclear fusion reactor must be created first before the plasma, right? Does this mean these reactors have some kind of secondary generators/batteries to power the fields either during the entire operation, or just for a period before the reactors create energy?
Yes, because those containment "fields" are also the mechanism by which the fuel is squeezed until it achieves fusion. In a modern fusion reactor prototype, those fields are magnetic. In Gundam, they're Minovsky particle i-fields, and in Macross they're artificial gravity.

Mobile Suits already have Minovsky particle condensers for storing Minovsky particles in compressed states for all manner of purposes, so those can presumably act as "starters" for the Minovsky reactor. In Macross, VFs have high-energy capacitors for similar purposes, though since thermonuclear reactors in that series consume such small amounts of fuel it's often more convenient to simply leave them running.
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Re: How exactly could people convert energy from miniature fusion reactor to electricity?

Post by False Prophet » Mon Dec 23, 2019 10:32 am

I think it's not likely to be so, but I still have got to ask: How much could outside temprature affect the working of a fusion reactor? I ask this while wondering about the existence of the GM Cold Climate. How the hell do you need an entirely unique variants for the artics? It got me thinking about how diesel engines are just the worse when it gets cold.

(I mean, supposedly that even the basic GM has thermal imaging, and its joints are perfectly serviceable you find a way to keep them from freezing up in the cold. Miniature heaters and automatic lubricators, perharps?)

(Also, I wonder if people have to treat jet fuel differently when both the temprature and oxygen level dropped when the plane goes up? And how the hell does jet fuel does not turn to gel? It is a type of diesel, just has lower octane, right?)

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Re: How exactly could people convert energy from miniature fusion reactor to electricity?

Post by Seto Kaiba » Mon Dec 23, 2019 7:44 pm

False Prophet wrote:
Mon Dec 23, 2019 10:32 am
I think it's not likely to be so, but I still have got to ask: How much could outside temprature affect the working of a fusion reactor?
Cold weather shouldn't have any effect on the operation of a fusion reactor. It could potentially have an impact on the generator, if you're using just plain water in the turbine generator's loop. If that freezes during a long period where the reactor isn't running, the water in the lines might freeze and render the generator inoperable. That said, it seems quite unlikely that the generator is using plain water and not something to reduce its freezing point (or a different coolant in the loop altogether).

False Prophet wrote:
Mon Dec 23, 2019 10:32 am
I ask this while wondering about the existence of the GM Cold Climate. How the hell do you need an entirely unique variants for the artics? It got me thinking about how diesel engines are just the worse when it gets cold.
Personally, I'd expect that has more to do with the drivetrain being adjusted for climate-specific operating conditions... like using lubricants that won't begin to congeal in cold temperatures, or applying special protective measures to keep particulates from infiltrating moving parts like sand shrouds and intake filters on a desert-use MS.

False Prophet wrote:
Mon Dec 23, 2019 10:32 am
(Also, I wonder if people have to treat jet fuel differently when both the temprature and oxygen level dropped when the plane goes up? And how the hell does jet fuel does not turn to gel? It is a type of diesel, just has lower octane, right?)
Jet fuel is kerosene, and ignites in high-compression situations. There's plenty of oxygen to sustain combustion due to the compressed air flowing through the engine. Aviation fuel starts to freeze at around -47C, but the friction of the air moving over the airframe, tank heaters, and the heat of the combustion process in the engine keep the fuel liquid.
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