If We Ever Get Sustained Fusion Reactions...Then What?

[Spacescifi]

Suppose one day man finds a way to actually contain a sustained fusion reaction via a magnetic field within a vacuum chamber?

Then what?

I am sure it can be exploited for energy production as far as electricity goes...SSTOs?

Not so sure.

We all know that barring we make materials that can survive temperatures beyond all known melting points of our best materials, we have to just cope with not being able to fully utilize fusion.

 

Is that not ironic? We cannot have torchships even if we HAD sustained fusion because the heat produced is too much.

So what could we use sustained fusion for anyway?

Did not. Mean to post twice. Delete second post please.

Edited November 11, 2020 by Spacescifi

[Hannu2]

It is a good question. I think main reason why fusion is always ready after 50 years is that it is solution to a problem which has not been invented yet.  Toroidal fusion powerplants will be extremely expensive and probably can never pay initial investment back. Fusion was promising during energy crisis when predicitons of energy costs was exponential, but now there are much more known energy resources and also renewable energy begin to be abundant and competitive with fossil energy. If there was a real economic need for fusion power in foreseeable future, large energy companies would invest hundreds of billions in development and we would get commercial plants in a decade or two. But in real life there is not any need and it is developed by small research funding of states.

I predict there will never be commercial large tokamak plants but there may be some special uses, like research reactors. It is not credible that they will be developed for spacecrafts in foreseeable future. Space budgets are so small. If there will be some significant business, like mining and refining of metals, fission reactors are much cheaper and faster solution. Next generations will probably get rid of hysterical nuclear fear caused by cold war propaganda and development of fission technology will be allowed again.

Unexpected breakthrough of another smaller and simpler fusion technology may lead to different development, of course. But I do not know how credible those ideas under investigation really are.

[DDE]

1 hour ago, Hannu2 said:

Next generations will probably get rid of hysterical nuclear fear caused by cold war propaganda

I'd say that's optimistic. Radiophobia is as strong as ever.

2 hours ago, Spacescifi said:

We all know that barring we make materials that can survive temperatures beyond all known melting points of our best materials, we have to just cope with not being able to fully utilize fusion.

You use MHD converters.

 

[KSK]

Fission powerplants aren't cheap either and yet they're built.

It's not an apples-to-apples comparison by any means but ITER has apparently cost €13 billion  (£11.57 billion at current exchange rates) whereas Hinckley Point C (UK nuclear plant under construction) is a £20 billion project.

I think the reason for the lack of commercial investment in fusion power is simply that it's still an expensive research project at the moment. Not many companies have the cash reserves to throw €13 billion at developing an untested technology. If and when it's shown to work, then you'll see the commercial investment, likely financed in the same sort of ways that fission powerplants are currently financed, at least to begin with.

I agree that fusion powerplants aren't going to space anytime soon. Quite aside from the cost, they're too big.

But 'going to space' doesn't have to be the measure of a technology's worth. If we 'just' use sustained fusion for electricity generation on Earth, I'm fine with that. Baseline power generation that's cleaner than fission and lower carbon than fossil fuels - sounds good to me.

Edited November 11, 2020 by KSK

[magnemoe]

2 hours ago, Hannu2 said:

It is a good question. I think main reason why fusion is always ready after 50 years is that it is solution to a problem which has not been invented yet.  Toroidal fusion powerplants will be extremely expensive and probably can never pay initial investment back. Fusion was promising during energy crisis when predicitons of energy costs was exponential, but now there are much more known energy resources and also renewable energy begin to be abundant and competitive with fossil energy. If there was a real economic need for fusion power in foreseeable future, large energy companies would invest hundreds of billions in development and we would get commercial plants in a decade or two. But in real life there is not any need and it is developed by small research funding of states.

I predict there will never be commercial large tokamak plants but there may be some special uses, like research reactors. It is not credible that they will be developed for spacecrafts in foreseeable future. Space budgets are so small. If there will be some significant business, like mining and refining of metals, fission reactors are much cheaper and faster solution. Next generations will probably get rid of hysterical nuclear fear caused by cold war propaganda and development of fission technology will be allowed again.

Unexpected breakthrough of another smaller and simpler fusion technology may lead to different development, of course. But I do not know how credible those ideas under investigation really are.

No we are not able to get fusion to work well as its hard, we can get it to work spending energy, not getting energy back.
But agree Toroidal fusion is probably an dead end, other ways looks cheaper. 

And an fusion engine is totally different from an fusion reactor. An engine don't need to create power, it has to create trust. 

[kerbiloid]

I believe in Green Powah and eco-friendly powerplantz. All hail Greta!

After these useful id_(ealis)ts make everything be plugged in outlets (or receive microwaves, no matter), and once the "green energetics" get collapsed, the outlets will be powered from all kinds of nukes just immediately.

The obvious eternal fuel is oceanic deuterium.
The oceanic lithium (irradiated inside the deuterium fusion reactor) is the source of tritium to make the helium-3 to catalyze the deuterium fusion.

So, once the technology reaches the augmented deuterium fusion, the events will run much faster.

Until that we just have enough rotten plants to burn them in air.

[Bill Phil]

I’m more optimistic for inertial confinement, seems like NIF doubled their energy yield recently as well. Maybe not but that’s a possibility.

Z-Pinch could work, and there are some cool concepts out there.

As for doing it in a magnetic field like a tokamak... well, it probably won’t do much for power, and will mostly be of interest for research purposes. 

For space propulsion either inertial confinement or Z-Pinch is probably the way to go. Sustaining the conditions for fusion just seems out of our reach.

@KSK Fission powerplant costs are dominated by legal fees and financial weirdness, not the complexity or difficulty of building the reactor. That said better standardization of reactor designs would help significantly as well as addressing the other issues. But that depends on large scale deployment of reactors. France seemed to manage it reasonably.

[vv3k70r]

6 hours ago, Spacescifi said:

We all know that barring we make materials that can survive temperatures beyond all known melting points of our best materials, we have to just cope with not being able to fully utilize fusion.

The issue is that plasma behaviour cannot be predicted now in real time and thus the magnetic force cannot be reasonably aplied (just to the spot) to prevent interaction with parts. That is the main reason of bad EROEI. So as far we have engine that get burned during work and it get really fast. We had same problem with jet engines on the early days and figured aout how to solve it (first demonstration engines works max 8h, and first usefull aplication max 20h) and we gonna do the same with fusion - it would just take "some" scientific efforts, more plasma research for models and cpu that handle the model in real time. It is one of many reason quantum calculators are build. Dont worry - we gonna get there, we did this before in smaller scale with weaker source. Obviously stars works and we gonna have them home^^

[Hannu2]

4 hours ago, KSK said:

Fission powerplants aren't cheap either and yet they're built.

It's not an apples-to-apples comparison by any means but ITER has apparently cost €13 billion  (£11.57 billion at current exchange rates) whereas Hinckley Point C (UK nuclear plant under construction) is a £20 billion project.

We have also one project in Finland, more than decade late and exceeded a budget by several billions of €. Olkiluoto 3. Now it is in finalizing phase.

But most of that is because bureaucracy level has been set to far beyond insanity. Nothing is enough to prove safety. If there were reasonable laws, nuclear plant would cost few billions and be economically profitable option. Small passively safe units, which are under development now, would be even (much) cheaper and safer.

3 hours ago, magnemoe said:

No we are not able to get fusion to work well as its hard, we can get it to work spending energy, not getting energy back.
But agree Toroidal fusion is probably an dead end, other ways looks cheaper. 

And an fusion engine is totally different from an fusion reactor. An engine don't need to create power, it has to create trust. 

I think conversion from heat to electricity is not the hardest thing in fusion powerplant. Fusion rocket engine have all bad problems how to ignite fusion and release actual energy. Plasma must be confined and heated to absurd temperature to get any energy and there is no known feasible ways to do it, except some very premature lab tests. I do not expect to see fusion powered spacecraft in my lifetime (statistically about 40 years left).

I am also quite sure that fusion will suffer also the most of political problems fission has. It is nuclear reaction after all and produce neutron radiation (which can be used to evil military purposes) and radioactive waste. Environmental activists accept never it and keep propaganda against it if commercial project sometimes begin.

[kerbiloid]

If the fusion reactor produces charged particles, they can be used both to induce electricity in wires and get the power, or to be thrown backwards as propellant.

KSPI-E contains ChargedParticles and magnetic nozzles, which can be powered by the fusion reactor.

Best use with aneutronic fusion fuels (B+H, N+H, C+H) 

Edited November 11, 2020 by kerbiloid

[Entropian]

46 minutes ago, kerbiloid said:

If the fusion reactor produces charged particles, they can be used both to induce electricity in wires and get the power, or to be thrown backwards as propellant.

I think you're talking DEC (Direct energy conversion).  The Venetian blind setup was used in a few test reactors but the main problem is that most of the energy released from D-T and D-D fusion is in the form of high speed neutrons.  Heat engines can be used, but thermodynamics shoots you in the back there.  p-B₁₁ fusion releases some energy in the form of charged particles, but then you end up with the insane hard x-rays you get from bremsstrahlung.

On the economics part, the kopek problem is something interesting to consider.

4 hours ago, Bill Phil said:

Z-Pinch could work

Nah, nasty pinch instabilities killed the idea decades ago.

4 hours ago, Bill Phil said:

seems like NIF doubled their energy yield recently as well

Please don't listen to them.  Their definition of "energy yield" is horribly flawed and widely condemned by the scientific community.  They actually redefined Q (breakeven) in order to say that their reactor got Q>1.

2 hours ago, Hannu2 said:

It is nuclear reaction after all and produce neutron radiation (which can be used to evil military purposes) and radioactive waste.

Problem is, neutron radiation is ridiculously easy to create.  Many companies manufacture commercial Farnsworth-Hirsch fusors for breeding high atomic weight isotopes for medical use.

Edited November 11, 2020 by Entropian
grahmahrr

[Bill Phil]

1 hour ago, Entropian said:

Nah, nasty pinch instabilities killed the idea decades ago.

I'm aware of the instability issues with Z-Pinch. Modern concepts are quite capable however and sheared flow stabilization could make it work. It's still decidedly non-trivial and new problems are likely to crop up, but even besides that the Z-machine did good work up until fairly recently, though I haven't looked into recent news on that front. Still, through experiment and bettering our understanding it could work.

Looks like they're doing experiments for MagLIF, sort of like fast ignition for Z-Pinch systems. And from what I can find they've massively increased their neutron output in recent years. Looks promising, though using the word "promising" for any fusion system is problematic in its own way.

1 hour ago, Entropian said:

Please don't listen to them.  Their definition of "energy yield" is horribly flawed and widely condemned by the scientific community.  They actually redefined Q (breakeven) in order to say that their reactor got Q>1.

Yeah, it's a yikers. Other facilities and scientists are working on confirming the claim or at least verifying as much as they can.

[wumpus]

The coal industry managed to kill nuclear while releasing more radiation than nuclear ever did (I think they even do per Watt, including Chernobyl).  You don't think solar and wind won't do the same?  More likely, it will simply never be economical to build fusion power plants, and it will never make sense to subsidize them until they are (although I'm sure that plenty will expect such to be done).

 

8 hours ago, KSK said:

Fission powerplants aren't cheap either and yet they're built.

Where?  There's no way you will get the loans in the US (the dollar per Watt loses even to coal, let alone the rest).  In the EU they have perfectly good nuke plants shut down.  They aren't at all popular in Japan.  Are China and India building them?  It would make tons of sense for them to do it, but I haven't heard of it.

[Hannu2]

14 minutes ago, wumpus said:

Where?  There's no way you will get the loans in the US (the dollar per Watt loses even to coal, let alone the rest).  In the EU they have perfectly good nuke plants shut down.  They aren't at all popular in Japan.  Are China and India building them?  It would make tons of sense for them to do it, but I haven't heard of it.

As far as I know, some EU countries build but others scrap working plants. In Finland there is one from French Areva in finalizing phase now, but it was intended begin commercial production at 2009. Also costs have about tripled from contracted budget and it is not juridically clear what part goes to manufacturer and customer (I think so, am not sure). Only sunken cost fallacy and prestige of many rich industrial owners and high politicians have prevented abortion of whole project. I think last estimate when commercial production begins is 2022 and you can guess how many jokes that project has been created.

https://en.wikipedia.org/wiki/Olkiluoto_Nuclear_Power_Plant#Unit_3

There is also another project with Russian company Rosatom, but I do not know what is the status now. It is in very beginning and has not yet final permission from government. It has been mainly out of publicity in last years and it may be that failed Olkiluoto project has scared owners. Also price of renewable energy has decreased significantly during last decade and there may be also some political issues with Russians now.

https://en.wikipedia.org/wiki/Hanhikivi_Nuclear_Power_Plant

[kerbiloid]

2 hours ago, Entropian said:

I think you're talking DEC (Direct energy conversion).  The Venetian blind setup was used in a few test reactors but the main problem is that most of the energy released from D-T and D-D fusion is in the form of high speed neutrons.

And as I wrote a sentence later, aneutronic reactors are the thing for the thrust.

While D+D is for ground plants.

[Entropian]

23 minutes ago, kerbiloid said:

And as I wrote a sentence later, aneutronic reactors are the thing for the thrust.

While D+D is for ground plants.

Sorry, I think there's a misunderstanding.  I was elaborating on the DEC for ground-based systems, not disagreeing with you.

[KSK]

2 hours ago, wumpus said:

The coal industry managed to kill nuclear while releasing more radiation than nuclear ever did (I think they even do per Watt, including Chernobyl).  You don't think solar and wind won't do the same?  More likely, it will simply never be economical to build fusion power plants, and it will never make sense to subsidize them until they are (although I'm sure that plenty will expect such to be done).

Where?  There's no way you will get the loans in the US (the dollar per Watt loses even to coal, let alone the rest).  In the EU they have perfectly good nuke plants shut down.  They aren't at all popular in Japan.  Are China and India building them?  It would make tons of sense for them to do it, but I haven't heard of it.

The UK - as mentioned in my original post.

And the folks that are pointing out that nuclear plants should be cheaper? No doubt but that wasn't my point. Their current costs aren't preventing them from being built (albeit not in great quantities), so unless fusion ends up being orders of magnitude more expensive still (which seems unlikely given the cost of ITER), then there's no reason to assume that cost necessarily be a barrier to building fusion plants.

Assuming they can be made to work.

[Nuke]

assuming iter/demo is successful and results in production fusion plants. 

power plants will be cheaper than research plants, as they need less instrumentation to function. but they are still going to be large and expensive. 

the first world gets them first.  and expect the same kind of bureaucratic heel dragging and politicization that goes with any mega project, made especially worse because its nuclear. it will be a slow process.

its going to bankrupt the middle east and anyone else running a primarily oil based economy. fusion will be very economically disruptive. 

its going to be just baseload for awhile. but expect a drop in the cost of manufactured goods. it will also reduce the cost of rocket fuel if you can convince elon to go hydrolox. 

theres a lot to be learned just from operating first gen fusion power plants. that knowledge will make 2nd gen power plants even better. fusion research is still going to be a thing. 

iter is huge by design. miniaturization would be desired, not to mention required for anything fun like fusion spacecraft. dont expect that to happen over night. 

extraplanetary bases become feasible. you can begin construction on a lunar colony, and with the reduced cost in rocket fuel and 100% reusable orbital vehicles,  fusion doesn't really need to undergo miniaturization first. 

we could have our lunar colony done in time for first gen fusion propulsion. 

 

keep in mind it can go a different way if a different method of fusion is the first to produce a successful demo. a smaller reactor would facilitate a more rapid deployment and lessen the economic disruption as more people can afford them and transition to fusion based economies. you might also see fusion powered spacecraft sooner. 

Edited November 11, 2020 by Nuke

[Bill Phil]

Rocket fuel isn’t all that expensive as is

[Nuke]

55 minutes ago, Bill Phil said:

Rocket fuel isn’t all that expensive as is

no but hydrolox  is a renewable when you have a power plant that runs practically for free. 

i have a feeling that even in a world of fusion torches, chemical fuel will still be the primary means of getting to orbit. perhaps supplemented with beamed power.

future iterations of space treaties will likely include a nuclear exclusion zone about the earth and any other heavily populated colonies. get your radioactives from space mining.

Edited November 12, 2020 by Nuke

[YNM]

On 11/11/2020 at 2:30 PM, DDE said:

Radiophobia is as strong as ever.

Especially given 2011.  The country where it happened seems to still be on the path to abandoning nuclear completely either, given they've ruled that it really was an oversight.

Fusion should be slightly less problematic - the by-products are not as long-lived and it's less energetic as well - but the heat is a terrible problem if something ever fails.

On 11/11/2020 at 12:18 PM, Spacescifi said:

torchship

I question anything that needs to spew nuclear explosions behind it, of either kind.

On 11/12/2020 at 9:55 AM, Nuke said:

hydrolox  is a renewable when you have a power plant that runs practically for free. 

Most hydrogen supplies are still from hydrocarbon since it's a lot less energy-intensive. I question if the fact will change with availability of "free" electricity. (and you bet the existing hydrocarbon producers will peddle it.)

[sevenperforce]

On 11/11/2020 at 11:18 AM, wumpus said:

The coal industry managed to kill nuclear while releasing more radiation than nuclear ever did (I think they even do per Watt, including Chernobyl).

Pure trivia here, but coal is so bad that it kills more people per kilowatt-hour than nuclear power even if you include Hiroshima and Nagasaki as part of "nuclear power".

[Nuke]

2 hours ago, YNM said:

Most hydrogen supplies are still from hydrocarbon since it's a lot less energy-intensive. I question if the fact will change with availability of "free" electricity. (and you bet the existing hydrocarbon producers will peddle it.)

that may be true now. but in a post fusion world the more energy intensive operation may actually prove to be the cheaper option.  really depends on the shape of the petrochemical industry post-fusion.

[Bill Phil]

3 hours ago, Nuke said:

that may be true now. but in a post fusion world the more energy intensive operation may actually prove to be the cheaper option.  really depends on the shape of the petrochemical industry post-fusion.

Actually I would say that water splitting is more suited to fission reactors, since most fusion reactors (even tokamaks) will likely be pulsed in nature at least somewhat, among other issues that fusion has. Fission on the other hand can continuously operate at high temperatures... which reduces the electricity need for water electrolysis. Electrolyzing hot water takes less electrical energy than electrolyzing room temperature water. This can be done with the heat from fission reactors. Meanwhile I'm not sure that fusion reactors will be as capable, not to mention more complex, for the task. 

Though you just need cheap heat, and there are a lot of sources of that. But nuclear fission reactors are a technology that can provide that heat, and fission reactors work now.

[Nuke]

10 hours ago, Bill Phil said:

Actually I would say that water splitting is more suited to fission reactors, since most fusion reactors (even tokamaks) will likely be pulsed in nature at least somewhat, among other issues that fusion has. Fission on the other hand can continuously operate at high temperatures... which reduces the electricity need for water electrolysis. Electrolyzing hot water takes less electrical energy than electrolyzing room temperature water. This can be done with the heat from fission reactors. Meanwhile I'm not sure that fusion reactors will be as capable, not to mention more complex, for the task. 

Though you just need cheap heat, and there are a lot of sources of that. But nuclear fission reactors are a technology that can provide that heat, and fission reactors work now.

fission and fusion reactors start looking more or less the same when you get into the thermodynamic loop. both are just over-glorified steam engines.  

you could also be electrolyzing with hydroelectric. at off peak hours you could be electrolyzing water rather than shutting off turbines, reservoir levels permitting. the hydro plants we have all around southeast alaska have very little to do at night, and its mostly rain forest round these parts (we make seattle look like a desert).