The Shocking Problem That Could End Nuclear Fusion

Did you know there is a big concern about fuel for nuclear fusion? This video looks into the problems and solutions!

I have been fascinated with nuclear fusion for a few years now and love finding out about new breakthroughs in the area. However, things are not always sunshine and rainbows, and in this video I wanted to look at the tritium shortages the sector faces. If these problems aren't resolved, this could be the end of the pursuit for commercial fusion energy.

Information sources:
Future of Fusion Energy [BOOK]

Video sources:
Storyblocks

Music:
Epidemic Sounds

[ZirothTech]

Thanks for all the great comments and discussions in the comments - I have been learning a lot from reading them all.

One common point is the use of helium-3, I probably should have mentioned it in the video, but the reason I did not is because I wanted to focus on the 'mainstream' fusion pipeline. The only company I have seen looking into this is Helion, which although is an interesting project, they are currently planning to create their helium-3 from D-D reactions, which I need to look into further. The other option is of course helium-3 on the moon, but I need to look into this more and it was diverting away from the key points I wanted to make in this video!

Watching out for a future video comparing all the types of fuel we could use for nuclear fusion!

[johnsavard]

I had always understood that this was not a "problem". It was known perfectly well that fusion power would not be usable, unless we had fusion reactors that could use only deuterium as fuel. Current attempts at making fusion reactors with deuterium and tritium as fuel are only intended as a steppingstone on the way to building a fusion reactor that will actually be useful.

[srelma]

Yes, tritium breeding has to be taken into account when designing a fusion reactor, but it's not like this is some brand new thing that nobody thought about before as your title suggests.

[calyodelphi]

I was worried at first that this video would be a grossly misinformed & fearmongering anti-fusion click-trap because of the title, but I have been pleasantly surprised. This is an extremely well-presented subject that presents the problem and its possible technological solutions. :)

[redcrafterlppa]

I watch fusion related videos regularly and I heard that they experiment with different element combinations other than tritium (since it's so problematic). They mostly use it now in the *_test_* reactors because it's the most optimal combination (yet) and what they try to get working are (primarily) the reactors. If you have an reactor producing net energy using d-t it's a good sign this design might be good. But if you try to work with hard fuels directly it might never take of. It's like trying to run one of the first combustion engines with tanker fuel.

Tritium breediing does not have to rely on the fusion reactors, it can also be done using other neutron sources. It adds to the cost but is feasible. As for the Lithium 6, as soon as te demand is there the facilities will be uilt, just like with any other material. the process of enriching it is well understood and the fact that a site that was poorly run decades ago is no longer operating does not necessarily mean that the method itself is unsuitable. Other than that a good video.

[lecturesfromleeds]

Even if it's a no go, money in this kind of research is never waisted. It furthers our understanding of plasma science and provides us with new ways of thinking when it comes to energy production

[nanolog]

I sincerely don’t get what the problem is supposed to be.
We have enough of Tritium to continue researching the technology for the next couple of years. Should there be the need for more Tritium, for example because of D-D fusion appearing too far out of reach, producing it may be costly, but trivial when it comes to the technology.
Neutron flux reactors are well understood and used in research all the time. Surrounding the neutron source with a blanket of heavy water, which is kinda abundant, will yield Tritium, as that’s just how it gets produced in the CANDU. You would not even need Lithium-6 for that.
Should Fusion power be commercialised, more efficient methods of producing it, for example in Lithium blankets, could and would be researched. But until then you could probably come by by just firing neutrons at some heavy water.

[roigrdj]

Together with the tritium self-sufficiency problem, there is also the not so evident but critical fact that tritium recovery and re-injection (done in the tritium plant) is not immediate. Given the low cross-section of the reaction, tritium burn-up ratio is rather low and most tritium (~95%) reaches the divertor without being burnt. This tritium, along with the bred one, must make all the way through the tritium plant and tritium recovery systems to be re-injected back into the chamber. Typical residence times in the tritium plant range from a few minutes to hours. So, during startup, a reactor will need enough tritium to sustain reaction during the recovery time (minutes at best), times 1/burn-up ratio (let's assume 95%, so times 20). That's a lot of tritium (tens of kilograms) needed beforehand, and just D-D breeding might not be enough.

[arnasvolcokas]

A good rundown of the key issues facing tritium production/consumption. However, there are a few issues I would like to point out:
- Claiming that scientists are "hiding" tritium problem is not true (and frankly a bit dishonest). This is a well known problem with large volumes of papers addressing it and any introductory material to fusion technology points out this issue;
- D+T reaction is not the only reaction possible (it is easiest to achieve) and it would be only a stepping stone towards even more sustainable fusion reactors. The video does briefly mention D+D reaction which could also be used to directly produce energy (requires higher temperatures hence harder to achieve);
- There is quite an obvious solution to producing initial quantity of lithium needed for fusion reactors - tritium breeding facilities (i.e. a modified fission reactor). And even with the current energy crisis in Europe we might see a renascence of nuclear fission power plants, some of which might be designed with tritium production in mind.

[simonemingozzi]

I just finished my Fusion Student days ( I guess I am more or less the same age as you) and I approached this video with my spider scam sense tingling... I did not know your channel... Well.. the scam sense was wrong... Good job man, this is a nice video with proper scientific backing data and sources mentioned. I do not agree with the background message that "they are not telling us" ... there are lots of papers focused on the breeding ratio problem... you also mention some of them... But I guess that youtube videos must have a catchy title and claim ;)... But still... a great video! My compliments! It left me with the thought that I may even be up to help you out on similar projects ;) In the meantime... Keep it up!

[sowhanQ]

If you think about it mining minerals in space can just solve all these rare element problems

[steve_wilson]

One comment, well after the fact. When someone puts "shocking" in their video title, that's most likely going to get ignored. Too many people are getting too dramatic with their titles and thumbnails, and it really detracts from the YT browsing experience. I'm not looking to be shocked. I'm looking to be entertained, engaged and informed. Your stuff is great, Ziroth - I really enjoy learning about interesting new developments in engineering, watching the science fiction of yesterday becoming the reality of today!

[HandbrakeBiscuit]

Just remember folks - the end of nuclear fusion could be only thirty years away...

[FLORATOSOTHON]

The idea of a Lithium blanket that will produce tritium for the Deuterium-Tritium fusion is quite old. I learned about it in a nuclear engineering course I had, as an engineering student about 40 years ago. However the main problem was not the scarcity of tritium, but the protection of the reactor's components from the neutron flux of the fusion reaction. Neutrons have the tendency to make the material they hit radioactive and cause them to transmute in to led eventually. This, for a 24/7 year round power plant operation, would require a tremendous amount of service and parts replacement. The other serious problem with the Lithium blanket, besides the scarcity of Lithium 6, is the fact that Lithium is flammable and ignites explosively. This would mean that the slightest leak of air coming in to contact with the lithium blanket, under high temperature conditions and the entire reactor would go up, like an old photographer's magnesium flash.
The best way to go with fusion would be the neutron free Deuterium-Deuterium reaction, however the starting temperature for such a reaction is at least 3-4 times higher than the Deuterium-Tritium reaction. This is a temperature level absolutely unattainable with current technology, possible maybe after 100 years at least.
In my opinion, with current technology, the best way to go until a Deuterium-Deuterium reaction becomes possible, is the liquid salt Thorium fission reactors, that appear to be safer and with much less radioactive waste than current Uranium fueled reactors. Also Thorium is much more abundant than Uranium and there is no issue about someone making nuclear weapons though the Uranium enrichment process or the nuclear waste reprocessing that could provide Plutonium.
PS.
If I remember correctly, Alpha particles hitting Beryllium produce neutrons. At least this was the way our lab's neutron generator worked, by using a Plutonium-Beryllim core and we would put our samples around it. So in what you describe, they probably want to use the Alpha particles produced by the fusion reaction to maximize Tritium production from Lithium, by enhancing even more the neutron flux.

[annekedebruyn]

Honestly, even if fusion turns out to be not feasable, I don't think it has been a waste.
We learned so much from this project.

[michaelchapman]

I saw an article about the discovery on the moon of rocks containing Helium 3 which was mentioned as a way to do fusion without emitting the troublesome neutrons. Since what we are really interested in is heat it would seem that this Helium based reaction would greatly simplify things. I don’t know why that isotope exists on the moon (and not apparently on earth) but I’d be interested in your comments on it.

[dion]

This is known and has been known. The large neutron flux was to be used to breed tritium. One method is using lithium blankets just behind the walls. The other well known issue is that the reactor materials become highly embrittled and radioactive. I learned this and far more in the 1980s. Of course if the pico second terrawatt laser shot used for lithium - proton fusion works as a reactor all these issues are avoided.

[listerdave]

The way forward seems to me to be that once sustained DT fusion is achieved we need to push forward and continue increasing the achievable temperature and confinement to the point where D-D fusion becomes self sustaining and thus do away with the tritium requirement except perhaps for starting up more easily. D-T fusion has always seemed to me as merely a prototype that is the easiest possible form of fusion just to get us started.
Once ITER is running a self sustained fusion it will teach us a lot about how to optimize the confinement performance meaning we will be able to achieve the same type of fusion with a smaller device and/or achieve a much harder type of fusion (D-D) with the same size of device.

[Brainsore.]

I love how all the comments are completely destroying this video’s clickbait title/concept. I learn something new every day.