Nuclear fusion has encountered a shortage of tritium
wired.co.uk
wired.co.uk
This seems like a non-sequitur. If we need to keep around (or even build) a few heavy-water fission plants to enable the fusion industry, what's the problem? The simple phrasing of fission as "dirty" really shows the quotee's biases. You could easily envision a stable energy mix with a few percent of fission, the rest fusion and storage/peaking power, and that would be far, far cleaner than our current GHG/pollutant-heavy mix of fossil fuels.
It seems quite premature to call this a "crisis" since we already have proven ways of manufacturing the required ingredient. I suppose the risk is just that this pushes up the price of fusion in the initial phases of deployment, providing an "activation cost" that delays fusion from taking over, but that's quite a speculative concern at this point.
It's actually tilted very far in the opposite direction. The ratio is something like 600:1 heavy-water fission to fusion. A mix of 99.8% fission and 0.2% fusion, if your fusion is relying on that as its sole source of tritium.
- "Small quantities of tritium are also produced by CANDU-type nuclear reactors—on the order of 100 grams per year for a 600 MW reactor,"
You'd need 60 kg/year for a 600 MW D+T fusion reactor.
I.e. this language:
- "Ni et al (1) estimate that one CANDU 6 reactor can produce 130 g of tritium per year, but this is based on physics, not actual production data."
https://scientific-publications.ukaea.uk/wp-content/uploads/...
ref. (1) is https://sci-hub.se/http://dx.doi.org/10.1016/j.fusengdes.201...
It's just not a physically efficient process. Heavy-water reactors weren't optimized to produce tritium; it was an unwanted contaminant.
Still, as I said originally, it sounds like keeping our current level of fission reactors around should solve the bootstrapping problem.
And I think their failure to really understand fusion power either. The sort of fusion reactors we build first will produce tons of neutron radiation, which over time will turn the whole reactor itself into radioactive nuclear waste.
The love for nuclear power some internet communities exhibit has far left the realm of the science people often invoke as their reason and gone into full-on scientism. Nuclear scientists have respect for radiation. They wouldn't take offense with the mere mention that it has unwanted byproducts. They built and ran a couple hundred reactors for a few decades, and only two of them managed to render large swaths of the landscape into uninhabitable wastelands, which is quite a feat. But it was only possible because they didn't minimize the danger with the sort of I-would-love-a-reactor-in-my-backyard attitude that seems to be prevalent now. Which is, by the way, not only getting the science wrong, but also the politics: nuclear power is out not because it is dangerous, but because it is too expensive and, at this point, too slow to build.
While science bros have been huffing isotopes, actual scientists, with the help of some eerily effective subsidies, have improved solar and wind power and battery technology to the point where it is competitive and scalable not just to replace nuclear power, but even coal. Why people keep making the same arguments as they did a decade ago, a time span in which those technologies became 80-90% cheaper and more efficient, cannot be explained by the natural sciences.
All or nothing. We must have completely clean power or it has no value.
Not using comparison. How does it compare to other sources of energy, (including solar which is built in facilities using coal power).
In a way, that last (...) is also a very black and white way of viewing things.
In what way is it black and white view of things?
Solar energy production is not 100% clean. It never will be regardless if coal is used or not. That doesn't mean it's bad. The goal isn't purely clean energy. The goal is improved sources of energy.
Hopefully coal isn't used in the future. But things don't appear to be on track.
https://www.carbonbrief.org/china-briefing-17-march-2022-bei...
Unfortunately, because black and white thinking and evaluating energy sources without comparing them has resulted in a shortage of natural gas (thanks to fossil fuel divestment and ESG) and energy producers falling back to coal. The worst possible source of energy.
[0] https://www1.psfc.mit.edu/research/alcator/pubs/APS/APS2018/...
I'd love if it fusion became commercially viable but I'm doubtful it ever will. At the least the kind involving fusion atoms in a plasma for all the documented reasons, most notably plasma turbulence and the power loss and container damage from neutron escapes.
I'm not that concerned about a shortage of tritium. That's a solvable problem. In fact we probably need a variety of breeder reactors for things like this and producing plutonium for deep space probes anyway.
Fusion is a trap for many because it seems so easy. I mean the Sun is doing a lot of it. But the Sun is relatively inefficient (which is compensated for by mass) and it solves the containment problem with gravity.
https://www.world-nuclear-news.org/Articles/ITER-tokamak-ass...
https://www.reuters.com/article/us-france-nuclear-fusion/ite...
Whatever you bring from outside is just to bootstrap it once you turn it on. (I imagine they are not collecting the tritium between runs, but it's something you are expected to do.)
There is another, unrelated issue that if we decide to scale (H + D) fusion power, for decades we will need more tritium than they can generate.
The only reason fission isn't more profitable is politics. Politics are making investment and research into fission needlessly costly.
It will cost at least a $billion to take apart and dispose of Indian Point, shut down recently because it was leaking radioactive stuff into the Hudson.
In Sweden, where I live, about half of our electricity is from nuclear. It's built and operated by a state owned entity called Vattenfall and while they currently have a politically appointed board that is against nuclear they operate (for profit) all of our nuclear reactors. The only reason we don't build more is because they've made it practically impossible (not illegal) to expand nuclear energy through various political motivated decisions. Sweden had a referendum on the continuation of nuclear energy after the Chernobyl accident, we did vote, though by a narrow margin to transition away from nuclear. However, this past winter we had huge supply issues and people ended up having to pay 4x for electricity due to the premature shutdown of nuclear (meanwhile we had to power up oil and gas burning to compensate). Right now, most people in Sweden are of the opinion that we should keep our nuclear reactors. I, together with several others would like to us to expand our energy production from nuclear to prevent a reliance on oil and gas.
Politics is how policy is determined. People have tried other ways. Sometimes they worked. For a while.
Diverting money from building out renewables (and transmission lines) to build nukes ensures, at minimum, another decade of increasing reliance on oil and gas, and then paying more for power than you would have for renewables.
Sweden cannot depend on solar alone, we have plenty of hydro in the northern parts of the country and wind doesn't work during winter. Wind also kills birds and insects, en masse.
People have an irrational fear towards nuclear. Fact is, very few people have died because of nuclear energy. If you compare deaths vs produced watts, nuclear is the single safest energy source by several orders of magnitudes.
Also, I don't know if that's a typo or a misunderstanding but we are not talking about nuclear weapons, i.e. nukes we are talking about thermonuclear energy production. These are two different things altogether.
Didn't know that fusion generators produced its own fuel! If it produces more than enough, then the excess tritium is considered radioactive waste?
The energy of the neutrons is transformed into heat by adsorbing them into some shielding walls. The materials for those walls will be chosen to minimize the quantity of radioactive waste that is produced by the extremely intense neutron irradiation, but it is impossible to avoid completely the production of radioactive waste.
So all the fusion generators planned for the near future will generate radioactive waste, but in significantly less quantities than fission reactors of the same power.
Because they produce an intense neutron flux, like the fission reactors, the fusion reactors can also be used for element transmutation by neutron capture, e.g. for producing tritium or for producing lightly-doped silicon crystals for the high-voltage electronic devices (by transmuting silicon into phosphorus).
However, such transmutation applications usually also need the use of a neutron moderator, to slow the neutrons down to whatever speed is optimal for producing the desired isotope, e.g. tritium. For tritium, heavy water can play both roles, of the neutron moderator and of the target containing the element to be transmuted.
Renewables do not incur such operating expenses. Put renewables and a fusion reactor on the grid, and fusion would never, ever win a bid.
"Fusion .. will generate ... less ... than fission"? The whole damn ten-thousand-ton reactor becomes radioactive waste in short order. Fortunately, none will be built, so it is only a theoretical problem.
Anyway, I imagine the people studying fusion have an answer to this, since it only requires normal centuries-old chemical knowledge.
I also do not believe fusion will ever be a competitive power source for stationary applications on Earth.
The people studying fusion are carefully restricting their attention to the immediate problems of getting it to work at all. E.g., ITER will have no lithium blanket.
They figure on building another whole reactor to be completed (initially guessed) 15 years later at (initially guessed) 4x cost to begin tackling practical difficulties of extracting useful thermal energy.
I don't know about fusion vs renewables, because renewables are better, but they need a lot of non-renewables to be manufactured. If a fusion reactor lasted 100 years, it would be a much better option than renewables.
It needs even bigger containment than a regular nuke because reactive molten lithium bursts into flame on contact with air. The oxidized product is an exploding cloud of vaporized radioactive drain cleaner. A thousand tons of lithium make a lot of drain cleaner.
And again, by that time all our power will be cheaply supplied by renewables with no disastrous failure modes, and maintained just by taking bits down and putting up new bits, in shirtsleeves when weather favors it.
That was one of the main questions the ITER was supposed to answer, wasn't it? AFAIK earlier designs were quite short-lived, but some small changes fixed it. We will know how long they last as soon as we don't have an ITER anymore.
What were these small changes that fixed it? Did they have anything to do with the cost going up by 3x?
Anyway, inducing radioactivity is not what would use it up. That just makes it super-expensive to do repairs. It would get used up through neutron bombardment weakening the crystal structure of the metals it is constructed of.
(I think it could be somewhat better if it were a fission reactor optimized for tritium, but I don't know the numbers for that. I think that would entail fast-neutron reactors with enriched ⁶Li blankets -- analagous to what the fusion reactors are planning to do).
When I saw this, I thought that sounded odd, shouldn’t the atomic number go down with radioactive decay? but it turns out that in this case what happens is one of the neutrons splits into a proton, an electron and an electron neutrino so the atomic number goes up by one (unlike the more familiar fission reactions of the heavier elements where the atomic number decreases). So much physics I’ve either forgotten or never learned.
For every A (the number of nucleons in a nucleus) there is a ratio between (A-Z) and Z (i.e. between the number of neutrons and the number of protons) for which the mass of the nucleus is minimum.
Any other isobaric nuclei have an excess of mass over the nucleus with the optimal neutron/proton ratio, so they will decay towards it. The nuclei with too many protons will capture electrons or emit positrons, while the nuclei with too many neutrons will emit electrons, increasing the number of protons with each emitted electron, until the optimal neutron/proton ratio.
For the decay products of uranium and thorium, there are always too many neutrons, so the normal beta decay is what always happens.
It is possible to artificially produce nuclei with too many protons, and there are a few such unstable isotopes that are produced naturally, which decay by the reverse beta decay (electron capture or positron emission), where Z decreases by 1 for every captured electron / emitted positron.
For A = 3, the nucleus with minimal mass is helium-3. Tritium has too many neutrons in comparison with helium-3, and it must get rid of them by emitting an electron.
> "Right now, the tritium used in fusion experiments like ITER, and the smaller JET tokamak in the UK, comes from a very specific type of nuclear fission reactor called a heavy-water moderated reactor."
You litterally just need to make more of these heavy-water moderated reactors, which are rare and approaching end of life, but certainly you can build more of them if it was the difference between having endless energy or not.
* In a perfect world, there would be a more ambitious program developing the breeding technology in parallel to ITER, Willms says, so that by the time ITER has perfected the fusion reactor there’s still a fuel source to run it
* Like many of the most prominent experimental nuclear fusion reactors, ITER relies on a steady supply of both deuterium and tritium for its experiments
* When it’s finally fully switched on in 2035, the International Thermonuclear Experimental Reactor will be the largest device of its kind ever built, and the flag-bearer for nuclear fusion
* And as ITER drags on, years behind schedule and billions over budget, our best sources of tritium to fuel it and other experimental fusion reactors are slowly disappearing
* Right now, the tritium used in fusion experiments like ITER, and the smaller JET tokamak in the UK, comes from a very specific type of nuclear fission reactor called a heavy-water moderated reactor
* “We’re hitting the peak of this tritium window roughly now.” Scientists have known about this potential stumbling block for decades, and they developed a neat way around it: a plan to use nuclear fusion reactors to “breed” tritium, so that they end up replenishing their own fuel at the same time as they burn it
* “Calculations suggest that a suitably designed breeding blanket would be capable of providing enough tritium for the power plant to be self-sufficient in fuel, with a little extra to start up new power plants,” says Stuart White, a spokesperson for the UK Atomic Energy Authority, which hosts the JET fusion project
* “It would be an absurdity to use dirty fission reactors to fuel ‘clean’ fusion reactors,” says Ernesto Mazzucato, a retired physicist who has been an outspoken critic of ITER, and nuclear fusion more generally, despite spending much of his working life studying tokamaks
* “After 2035 we have to construct a new machine that will take another 20 or 30 years for testing a crucial task like how to produce the tritium, so how are we going to block and stop global warming with fusion reactors if we will not be ready until the end of this century?” says Mazzucato
Arthur Turrell's book, The Star Builders, is an excellent overview of the state of the art of nuclear fusion technology. Unfortunately, however, fusion is unlikely to be radically cheaper than other sources.
HN threads are supposed to be conversations, and conversation involves people interacting with each other.
The answer depends on the reactor design, which Elon doesn't know. There are a lot of possibilities, and if the first ones are too expensive, later ones might not be.
The cost of renewables + storage to provide "synthetic baseload" is likely less than fission. And DT fusion is likely more expensive than fission.
It also uses US fission prices, which are higher than in most of the world. On top of that, the US has unusually good geography for both wind and solar. Nuclear is much more competitive in many other countries. One ironic example is Germany, where the model suggests a 100% nuclear grid even at US nuclear costs, as long as the lifespan and discount rate are corrected.
https://www.sciencedirect.com/science/article/pii/S030142151...
Skip down to Figure 12 for a quick summary.
Also, do you have a source for early French costs being unverifiable? I don't see where that's mentioned in the paper, so it doesn't seem right to just dismiss the data unless there's another source giving us good reason to do that.
As for the EPR, seems to me the conclusion there is just to not build any more EPRs.
"Because we haven't needed more until now, and it's mostly man-made."
There wasn't any plutonium on Earth, either, until we decided we needed some.
Because the longest-lived isotope of plutonium has a half-life close to 100 million years, so some 45 halvings have happened since the Earth formation, almost all primordial plutonium has decayed by now.
A few atoms of the primordial plutonium are still around us, though they are much too few to be easily detectable (there have been claims that some very sensitive experiments have detected them).
...it’s estimated that working fusion reactors will need up to 200 kg of it a year
There are also at least four companies working on proton-boron fusion, though all but one are very small. (TAE is the exception.)
At least D-3He might possibly be made to produce economically competitive power, if there were any 3He to burn in one. But it might be useful in space probes.
> Tritium breeding was originally going to be tested as part of ITER, but as costs ballooned from an initial $6 billion to more than $25 billion it was quietly dropped. Willms’ job at ITER is to manage smaller-scale tests. Instead of a full blanket of lithium surrounding the fusion reaction, ITER will use suitcase-sized samples of differently presented lithium inserted into “ports” around the tokamak: ceramic pebble beds, liquid lithium, lead lithium.
> Even Willms admits that this technology is a long way from being ready to use, however, and a full-scale test of tritium breeding will have to wait until the next generation of reactors, which some argue might be too late. “After 2035 we have to construct a new machine that will take another 20 or 30 years for testing a crucial task like how to produce the tritium, so how are we going to block and stop global warming with fusion reactors if we will not be ready until the end of this century?” says Mazzucato.
You can't respond to the bad guys with a plea for them to stop what they are doing because you would rather spend the money on something else.
That isn't to say that battles should not be picked carefully, just that sometimes you don't have a choice and have to deal with a situation and spend lots of $$$ and sometimes blood in order to avoid a worse situation. Even in the context of "last 2 months alone" it isn't clear what specific action is being referenced so the comment is just too abstract, IMHO.
In some cases it makes sense to engage, in others it doesn't. There is no single correct answer unless you want to enter into a discussion of pacifism.
We don't know the future, and we keep being surprised by it!
If we want to fund more renewables than we are now, then the place to cut back is the many fossil fuel projects that we're still investing in. Until we've done that, I think any positive effort deserves applause instead of complaints about focus.
ITER is not necessarily the best approach to fusion, although it's the best funded.
In any case if we can't breed tritium than we either need to shoot for higher energy D-D fusion or some other reaction or fusion will never be cost-competitive.
I mean fusion capable of practical power generation.
D-T fusion is the easiest, and yet super hard. Tokamaks are the only design that we know how to build in order to meet the goal, with maybe stellerators in second position. Inertial fusion work for scientific and military experiments, but are far from being a usable power source. Things like fusors and its derivative are great hobby projects with a few limited practical applications, but we are not even sure if it is physically possible to produce more energy than we put in. As for LENR (aka. cold fusion) we are essentially at the "thought experiment" stage, when it is not a scam.
One other idea that may work with current tech is to dig a large cave, line it with really thick material and detonate hydrogen bombs inside it, extracting energy from the heat of the explosion. I don't think I need to tell you that even if we can do that (unsure), we certainly shouldn't (absolutely sure).
Or, take, advantage of that really big fusion reactor we already have and makes us go around in circles.
There are also various alternative designs, like Zap Energy's z-pinch, General Fusion's magnetized target fusion, and Helion's field-reversed configuration. Helion is attempting hybrid D-D/D-He3 fusion, the other two are D-T.
Probably the biggest problem is wasting time and budget on such dead-end technology as Tokamak, which can never in anybody's wildest dream be competitive with renewables, even given abundant tritium. But the conceivably useful D-3He aneutronic fusion depends on a supply of 3He, which is uniquely a product of tritium decay, and thus also depends on a tritium supply.
Thus D-3He would not be useful for baseload civil power, either. But it could be the only useful power source for projects in the outer solar system, for which a much smaller amount of 3He would suffice. It is hard to imagine another power source adequate in the outer solar system (aside from pB11 fusion which would be super if it is actually possible at all).
(No, mining 3He from the moon would totally not work at all.)
The whole point is to reach a Deuterium or Hydrogen reactor with a light lithium ignition in a lot of cases which would be easier to fuel than Tritium due do problems extracting it.
https://news.ycombinator.com/item?id=31428469
https://pv-magazine-usa.com/2022/05/16/a-fate-realized-1-tw-...
If the quantity of energy produced by nuclear fusion would remain negligible in comparison with the solar energy, then there is no need for it.
While on Earth using the nuclear fusion makes little sense, mastering it could enable the exploration and even the colonization of the Solar System.
Given these scales I'm not really sure $50 billion is a lot of money for the entire world to spend on an energy R&D project. In fact, that number seems surprisingly low, do you have a source for it?
Your mention of cost justification is ignoring the bigger picture that our economic system is setup to benefit public companies like Intel, and not grand research endeavors.
As an exercise to the reader, imagine what organizations/companies would exist if the contemporary economic incentive structures were different.
As far as making fusion reactors to boil hot fluids to drive steam turbine-generators to power the electrical grid... doesn't seem too likely. High-efficiency monocrystalline Si PV panel fabs would be a better investment.
Too expensive for clean power, just right to threaten the world
For those unfamiliar, I am talking about Project PACER. The fusion reactor proposed by Teller after the creation of the thermonuclear weapon. It may sound fanciful but it’s based on a simple precept. We can already induce fusion reactions, albeit in an unstable and explosive fashion. What if we took that warhead, surrounded it with a giant underground chamber made out of steel several feet thick, and let it explode while molten fluoride captured the heat?
Their work conclusively shows that this can be done, and that molten fluoride salts could capture most of the neutrons to prevent embrittlement. A single such facility could power the entire country. Oh and it could be configured to create Tritium in the process.
https://en.wikipedia.org/wiki/Project_PACER
The project was terminated because it was "bound to be controversial" and would "arouse considerable negative responses."
The math is sound. The concepts are sound. We could solve the comparatively minor engineering challenges and build one today while waiting on the the breakthrough needed for controlled, continuous fusion.
A second disadvantage is that the parts would undergo constant thermal cycling. Conventional reactors are run at a very steady output level to handle base load, because turning them up and down regularly would cause the moving parts to fatigue and crack over time.
https://books.google.com/books?id=4QsAAAAAMBAJ&pg=PA18#v=one...
So the idea is to drop 2 nuclear bombs per day to get about as much energy as one gets from a pair of nuclear fission reactors? I seriously doubt that's cost-competitive with fission power.
It's the most competitive non-intermittent and geographically independent source of carbon-free energy. Because it's the only such source.
In areas without hydroelectric and geothermal potential, nuclear is the most competitive carbon-free and non+intermittent option. Because it's the only option. That's why for all your insistence that nuclear is uncompetitive, it produces more electricity than wind and solar combined.i
Renewables plus local storage, transmission line, and/or ability to burn imported ammonia or hydrogen suffices, and at radically less cost, with no risk of rendering large areas uninhabitable.
Wind and solar is really wind, solar, and fossil fuels. Assuming that we'll be able to replace the last item with energy storage is betting the future of our climate on an engineering breakthrough. No such gamble exists with nuclear, countries like France have successfully produced nearly all their electricity with nuclear power for decades.
Turns out a daily detonation of a fusion bomb tends to wear on things and when those things fail... you've just detonated a fusion bomb.
One does have to appreciate how these guys took anti-proliferation concerns with the nuclear industry and said "fuck it, everyone knows we're only doing this to make bombs, so lets make a shit ton of bombs". No more concerns about terrorists getting their hands on some yellowcake and making a dirty bomb. Now they have a full up H-Bomb factory moving so much product that security can get complacent.
It's so widely impractical.
Teller et al anticipated your objection. It’s why the reactor is supposed to dig into sold rock. If there’s a catastrophic failure then it’s yet another subsurface nuclear test. And the more advanced designs considered for Project Plowshare produce minimal residual radioactivity. All of the products dissipate within 6 months.
So, in the worst case scenario, the facility gets buried under tons of rocks, far away from any water. And the residual radioactive products rapidly decay into being harmless with 6 months. Any induced radioactivity from the neutrons produced during the explosion will follow a fairly predictable pattern as well.
This can be done.
In exchange we get a reactor that creates nearly limitless power for entire countries.
We also don't end up creating a literal nuclear weapons manufacturing plant in every nation that wants to use this (since the "fuel" for this reactor is constantly detonating nukes).
Anything is better than the "drop a nuke in the hole" plan. Both Gen III+ and Gen IV reactors can hit the market before all the red tape is cut for prototyping the hole bomb.
I wonder which two senators are going to be ok with detonating 32 bombs in their state every day? This isn't the 50s, NIMBYs know how to make your life a living hell when trying to do anything nuclear.
Solutions that rely on a steam turbine generally lose to those that do not. A need to fool with fuel and security cost even more. Account for the disaster insurance subsidy and decommissioning cost, and they come out a marked drag on society.
That is, if you manage to complete one before it gets cancelled because renewables are already doing the job more cheaply than it can. We do better not to spend the initial $billions on what will never produce any marketable power. No such money is ever returned.
A nuke that runs only at night costs almost twice as much per kWh.
There are a lot of processes we don't fully understand so your claim is hard to substantiate. Also, if that was the case then a lot of people would probably just accept their fate.
From the wiki,
> A typical design called for a 4 m thick steel alloy blast-chamber, 30 m (100 ft) in diameter and 100 m (300 ft) tall,[9] to be embedded in a cavity dug into bedrock in Nevada. Hundreds of 15 m (45 ft) long bolts were to be driven into the surrounding rock to support the cavity. The space between the blast-chamber and the rock cavity walls was to be filled with concrete; then the bolts were to be put under enormous tension to pre-stress the rock, concrete, and blast-chamber. The blast-chamber was then to be partially filled with molten fluoride salts to a depth of 30 m (100 ft), a "waterfall" would be initiated by pumping the salt to the top of the chamber and letting it fall to the bottom. While surrounded by this falling coolant, a 1-kiloton fission bomb would be detonated; this would be repeated every 45 minutes. The fluid would also absorb neutrons to avoid damage to the walls of the cavity.
You can see the general design here, https://nextbigfuture.s3.amazonaws.com/uploads/2016/01/zyrEF...
>"Dropping about two bombs a day would cause the system to reach thermal equilibrium, allowing the continual extraction of about 2 GW of electrical power."
Now... the part you're not getting is that if you can do all that, you can almost certainly just use conventional fission power generation, which is what we really, REALLY need to be doing anyway.
(more info) What are the reasons that nuclear fusion power generation is not yet realized? https://www.quora.com/What-are-the-reasons-for-nuclear-fusio...