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Wendelstein 7-X Fusion Reactor Produces Its First Flash of Hydrogen Plasma (gizmag.com)
Zothecula writes: Experimentation with Germany's newest fusion reactor is beginning to heat up, to temperatures of around 80 million degrees Celsius, to be precise. Having fired up the Wendelstein 7-X to produce helium plasma late last year, researchers have built on their early success to generate its first hydrogen plasma, an event they say begins the true scientific operation of the world's largest fusion stellarator.
And I wish them godspeed. Energy and information are the fundamental limits of the human condition. Fundamental leaps in either arena will be transformative.
https://m.youtube.com/watch?v=R0PYe-4090g
So I've read the Wikipedia articles on the 7-X and on stellarators in general, but I'm not a physicist.
Can someone knowledgeable tell me how to feel about this? Does this represent meaningful progress toward fusion power? If so, how meaningful? Is fusion still 50 years away, or are we down to 49 now?
Sorry, what definition of precise are we using here?
I'll be glad when we get through this shakedown period of falling editorial quality by ... well, by timothy, actually.
Lost at C:>. Found at C.
Our helium shortage is over! (And I suspect the government was anticipating this when they put the strategic helium reserves up for sale.)
I've abandoned my search for truth; now I'm just looking for some useful delusions.
You should feel whatever you feel, unless you're a robot, in which case: /apply feeling hopeful.
Part of the fusion problem is keeping the hydrogen confined in the plasma. A stellator does this by shaping the magnetic field in such a way that the plasma twists and constricts itself. So instead of constraining a moving plasma, the moving plasma constrains itself.
This requires a precise shaping of the magnetic field via superconducting magnets, and the design of these has only recently become possible with advanced calculations on supercomputers.
So this is a test run of a new kind of fusion reactor. If it works, it will change the world. And so far so good, but we won't know until it works until all following tests succeed.
Nope, still 50.
I'm not particularly knowledgable, just an armchair physicist. I can only dream of a different path taken where I would have done this research. And keep in mind that fuel costs are a tiny drop in the bucket for a modern fission reactor. They could increase 100-fold without significantly altering the end-user cost of power. Fusion is still going to require big, expensive plants (they will just have lower fuel and waste handling costs). With that being said, there are a few BIG problems to overcome (but no one climbed a mountain with a single step).
Materials - Tritium / Deuterium fusion is NASTY, but it's what we're going to be able to get to at first. As in, higher neutron-flux than a commercial fission reactor nasty. Neutron damage causes lots of weird effects including metal embrittlement and radioactivation. Getting confinement good enough for net power generation is a big problem, but so is keeping the machine pieces operable for an economically feasible length of time.
Energy harvesting - T + D fusion is again unpleasant for this. Because a large portion of the energy released from this fusion is in the neutron it throws, most of the schemes for turning fusion into electrical power involve using the neutron to heat stuff up (like a liquid lithium blanket) and then go through a standard heat-to-steam turbine cycle. Less than ideal.
Confinement - We're going to start with T + D fusion. Which has already been super hard to get a magnetic field the right shape and strength to support. But where we want to end up is simple Hydrogen (a proton) + Boron. There are several challenges (power balance, temperature/pressure/density) here but they can be summarized as being 500 times greater than simple T + D fusion. This kind of fusion won't produce nearly as many neutrons, which means most of the energy will be in the form of charged particles that can be directly harvested for energy. Which is great, but it's 500 times as hard as the thing we haven't achieved yet.
As a former program officer for the Office of Fusion Energy, US Department of Energy I can assure you even if the Stellarator "works", it will not be a practical source of power. The complex engineering and cost make harvesting energy from fusion impractical.
I could fill a page on enumerating them. For one -- fast neutrons can destroy any material known. No one has come up with a design for the the first wall that captures the neutrons and energy.
The old quip is "Fusion has been 25 years in the future for the last 50 years.
The "50 years away" stuff is a really unfair criticism. The amount of progress that's occurred in the past several decades is many orders of magnitude - JT-60 has even gotten to Q=1.25, which means they were getting 25% more power out than they were putting in to maintain the reactor in steady-state operation.
Part of the reason that this concept got started was because of a big mistake early on with the ZETA program. Unbeknownst to them, A) heavy electron bombardment of their detectors was leading to false spectral shift readings, making them think that the temperature was much hotter than it was, and B) there was a possible method to create neutrons that they were unaware could be significant - heavy localized acceleration of ions causing spallation impacts. The unfortunate part was, by coincidence, (B) happened to produce roughly the amount of neutrons that would be expected by (A). So they thought that they were just a short step away from a viable fusion reactor, when in reality they weren't even close. Due to the more primitive technology at the time, not only did they not have detailed computer models that could have warned them to expect the neutrons, but they also didn't have a convenient way to measure neutron energies (it was this that later proved their early conclusions wrong). Their lack of computer models also meant that they were unaware of how much of a problem drift would be.
It's a very different situation today. There's really no question that we can viably produce fusion power today. The real question hanging over our heads is, what is it going to cost? How can we engineer a system to produce power affordably? And that's the real question that's going to take a lot of work to figure out. One thing is for sure, though: the higher the magnetic fields you can get for a given cost, the vastly easier it becomes. And these new high temperature superconductor tapes could push us leaps and bounds even beyond ITER, whether you go with a stellerator, a more traditional tokamak, or really anything else that employs magnetic fields. It's very encouraging for the field to see a route that already looked to be on a positive path get such a "bonus".
It's times like this I wish I had a friend named 'The Professor'.
W7-X is there two test two things. The confinement properties of quasi-axisymmetry and Island diverters.
It's still more like 50 years towards fusion. The Wendelstein was only built to investigate how well stellarators can confine plasma over a long period of time. No fusion will actually happen in this facility.
A stellarator is one of the three most promising plasma confinement methods:
* Magnetic confinement by means of the Lorentz force. There are actually two ways to achieve this:
- Confinement with toroidal/poloidal coils and injection of an electrical current into the plasma. This is usually done by induction and can, as such, only operate in a pulsed mode (imagine the plasma as the second coil of a transformer). This method will be used by the ITER which is built in France.
- Confinement with strangely looking magnetic fields. The intrinsic movement of the particles due to temperature is enough, no need for external current injection. But the "current" does not have a clear direction anymore, so instead the magnetic field lines need to be set up appropriately. This problem is computationally a little difficult and could only be adequately solved relatively recently. This is the stellerator approach used in the Wendelstein.
* Inertial Confinement. This is used at the National Ignition Facility (NIF) in California. Basically, a pellet of fusion fuel is ignited with very short, very high power laser pulses. The ignition of the outer layers of the pellet will also compress the inner material, creating the conditions for and initiating fusion. The inertia of the fuel's mass holds it together long enough for quite some fusion reactions to happen. Obviously, this approach can only operate in a pulsed fashion as well.
To my knowledge, only Tokamaks and the NIF have successfully initiated (controlled) fusion. But none have actually ignited the fuel (i.e. made the reaction self-sustaining), much less achieved the point of break-even.
So while this work is very important and interesting, I wouldn't expect proper fusion reactors any earlier than 50 years from now.
I wish I had mod points (and hadn't posted a couple of times already), but thank you for an excellent post.
Germany's newest fusion reactor is beginning to heat up, to temperatures of around 80 million degrees Celsius
80 million Celsius? That's on par with a Hot Pocket that's been microwaved too long. I wonder if they are using Hot Pocket technology. ;)
Anons need not reply. Questions end with a question mark.
There is also the element of funding for R&D. In the late 70's the DoE produced a fusion roadmap based on different funding levels. There was a crash program forcast which would have led to commercial fusion in 10-15 years, a robust development program that would led to fusion in 15-20 years, and a point where if funding remained below a certain level, would never lead to commercial fusion. Guess what funding level was chosen (well below the "fusion never" level). So the joke of "fusion is the technology of the future and always will be", is a result of no real investment being made. Sure ITER may be a $15billion project, but its also a 50 year long project. First announced in 1985, first plasma wont occur till 2025, that's 40 fricken years later, not exactly demonstrative of an intensive focus on developing fusion energy. Compared to what we invest in developing other sources of energy, its chump change
We're still 50 years out. This is like every other fusion reactor that's made fusion: An experiment for one part of a proof of concept for a proof of concept for a proof of concept of the real thing.
I had a couple of friends in undergrad physics who went to grad school to study plasma physics to work on this. Both dropped out after about 2 years citing that thy couldn't wait five years and went on to get phds in solid state (more money). This was 2 years ago.
I thought they were done with all nukes?
Almost there boys! Come on, it ain't rocket appliances!
As an engineer working in the fusion field, I would not agree it's quite so rosy a picture. *Lots* of issues need to be solved technologically, although I agree with you the physics side of Tokamaks is relatively understood. I.e. it would be a huge shocker if ITER didn't produce the power expected. Tokamaks are however very unreliable with stability, and whether or not these can be controlled and mitigated enough for reliable power production remains to be seen. Further, going from ITER to DEMO is like launching a rocket to space vs. going to the moon; the high energy neutron flux from a fusion reactor will centimeters of the first wall to powder. Getting enough lithium around the wall for tritium breeding and heat removal for a steam cycle is very difficult.
In the end, it's all economics as you say. I can't imagine with the present state of technology a viable commercial fusion reactor online until past 2100. ITER will be ~2030, DEMO ~2070 if ITER cost/is any clue. Say you're making a decision for a company - would you rather spend $20 billion dollars on a very finicky tokamak fusion reactor with tremendous maintenance costs (tritium recycling, lithium management, disruption and instability mitigation systems, etc.), or a gen III or IV nuclear reactor - perhaps a thorium molten salt reactor - that produces the same power reliably for a small fraction of the cost?
Commercial fusion will happen eventually, but in my opinion not without tremendous advances in materials science and superconducting magnets. One can imagine with clever first wall materials and >20 T fields using advanced BSCCO superconducting materials (or other) a reactor might become as affordable as a fission reactor of the same power output. Contrary to what fusion researchers will have you believe, fusion will always be in economic competition with fission.
This PDF sums it up pretty nicely: http://www.askmar.com/Robert%20Bussard/The%20Trouble%20With%20Fusion.pdf
It is the latest and biggest experiment in an ongoing chain and not the first working stellerator confinement, either. So Wendelstein 7-X is strictly speaking not of a new kind, but rather of the *other* kind of desgin besides Tokamaks: more complex, more challenging, but also without some of the inherent drawbacks. It's not yet clear which design will make the better reactor in the end.
How can we engineer a system to produce power affordably?
Ask Elon to do it!
Oh, I'm sorry sir, I thought you were referring to me, Mr. Wensleydale.
Posts like this are why I love /.
The Wendelstein was only built to investigate how well stellarators can confine plasma over a long period of time. No fusion will actually happen in this facility.
Incorrect. The Wendelstein will reach pressures and temperatures necessary for fusion. Fusion will occur in it unless something seriously goes wrong. What won't happen is electricity generation.
You are correct on the 50 years though - the director of the Wendelstein mentioned that there will need to be another generation of test systems before power generation will be able to be seriously considered.
I don't read AC A human right
It's a materials issue.
It took us a decade to solve the materials issues required to get to the moon.*
The conditions the material must withstand are much more precisely known now; I predict quicker progress in metallurgy, etc. will lead to increasingly efficient designs in the next decade.
If the fusion is clean as per radiation AND carbon, who the fuck cares if V1.0 is inefficient? The fuel is SEAWATER, we're not going to run out of it soon.
*Fuck you. They went. "Magnificent desolation." - Edward Eugene "Buzz" Aldrin
Stellarator? Sounds like something Dr. Doofenschmirtz would build.
"Behold, Perry the Platypus! My Stellarator! It will make anyone it zaps think they are Marlon Brando in 'A Streetcar Named Desire'!"
WTF is this? A knowledgeable reply containing a citation to a scholarly article?
Has Slashdot come to THIS?
I'm taking my sockpuppet and going home.
Germany migrates away from nuclear fission power, yes. But Germany is still funding science, and that not only if there is "return on investment" to be expected before the next elections.
Might be that fusion power won't be required right when it becomes feasible. But humankind might be happy to have it at hand during the next ice age.
The plasma facing material faces a flux of 1 neutron per 17,6Mev. By contrast, nuclear fuel cladding faces a flux of ~2,5 neutrons per 202,5 Mev, or 1 per 81 MeV. It's certainly higher, but it's not a whole different ballpark. And yes, you're dealing with higher energy neutrons but in a way that can help you - you've often got lower cross sections (for example), and in most cases you want the first wall to just let neutrons past.
There's a number of materials with acceptable properties. Graphite is fine (no wigner energy problems at those temperatures). Beryllium is great, and you need it anyway. In areas where the blanket isn't, boron carbide is great. Etc. These materials aren't perfect, but they're not things that get rapidly "converted into dust" by neutrons. Really, it's not the first wall in general anyway that I'd have concerns about, it's the divertor. The issue isn't so much that it takes a high neutron and alpha flux and "erodes" fast - that doesn't change the reactor's overall neutrons per unit power output ratio, and if you have a singular component that needs regular replacement, said replacement can be optimized. The issue is that you have to bear such an incredible thermal flux on one component. Generally you want to spread out thermal loads, it makes things a lot easier.
It's times like this I wish I had a friend named 'The Professor'.
Hmm, thought... and honestly, I haven't kept up on fusion designs as much as I should have... but has there been any look into ionic liquids as a liquid diverter concept? In particular I'm thinking lithium or beryllium salts. They're vacuum-compatible, they should resist sputtering, they're basically part of your breeding blanket that you need already... just large amounts, flowing, and exposed. Do you know if there's been any work on this?
It's times like this I wish I had a friend named 'The Professor'.
This requires a precise shaping of the magnetic field via superconducting magnets, and the design of these has only recently become possible with advanced calculations on supercomputers.
You're being vague and a bit over top if not misleading. Stellarators simply use twists in the magnetic field shape, so that particles, which mostly follow the field lines in a circle around such machines, are on average pushed outward as much as inward as they go around. If there is some instability that causes particles on the outside to get pushed out, then after a twist, they will get pushed inwards instead. It doesn't work this way for every possible kind of instability, but it removes some of the big ones that tokamaks instead try to brute force with stronger magnetic fields.
They don't inherently need supercomputers to be designed, as they existed as far back as the 50s. Although it takes quite a lot of computational ability if you want to make an efficient one and scan through a large parameter space, but the fields and coils from any given design can be analyzed on a normal computer. Modeling the plasma behavior on the other hand is a little more difficult as there are not as nice of symmetries as in a tokamak that allows some simplifications to be made, but progress is being made quite quickly on modeling efforts.
The plasma facing material faces a flux of 1 neutron per 17,6Mev. By contrast, nuclear fuel cladding faces a flux of ~2,5 neutrons per 202,5 Mev, or 1 per 81 MeV. It's certainly higher, but it's not a whole different ballpark.
The fusion situation is worse, because the total neutron flux is still much higher for a given unit of area and volume. Higher neutron energy doesn't mean messier collisions for the most part, and that energy just gets spread out over a larger volume.
Regardless, the total neutron flux is higher in a fusion reactor. A fission reactor might see on the order of 10^23 neutrons per square meter over the entire 40-50 year lifespan. Fusion reactors are estimated to be on the order of 10^26 per square meter per year. 10^24 corresponds to about an average of one displacement per atom in the absorbing material. So on average the fission reactor material only has about 10% of its atoms displaced over the lifetime, while the fusion reactor would have, on average, every atom displaced hundreds of times over the lifetime.
There is a reason why there is a big push for testing of materials under fusion conditions, and for facilities like IFMIF and use of artificial neutron sources, because just placing it in a research reactor is not going to cut it.
Really, it's not the first wall in general anyway that I'd have concerns about, it's the divertor. ...Generally you want to spread out thermal loads, it makes things a lot easier.
The divertor has a lot more flexibility and a lot of ideas already being tested, in part because the plasma can be controlled better than the neutrons. The impact point can be moved with time and deferentially pumped to give some more material flexibility. The blanket on the other hand is much closer to the bulk plasma, and you're limited to low atomic number material or tungsten (or maybe not even tungsten).
How can you make generalized statements like that? Cross sections vary by many orders of magnitude Fission reactors are generally made of steel, which is hardly setting any records in terms of low cross sections. The smaller the reactor, the less material you have to replace, and the more expensive the material you can use. And being "displaced" is not a fundamental universal material property effect, it depends on how the material responds to radiation damage, which varies greatly. Generally materials respond better at high temperatures (annealing), and fusion reactors operate of course at far higher temperatures than fission reactors.
I have trouble seeing how one would consider neutrons per square meter to matter more than neutrons per MeV. Because neutrons determine what you're going to have to replace, and energy determines how much money you get from selling the power to pay for said maintenance. You can spread it over a broad area and do infrequent replacements, or have it confined to a tight area and do frequent replacements, the same amount of material is effected. Some degree of downtime for maintenance is normal in power plants - even "high availablility" fission plans still only get ~85% uptime.
It's times like this I wish I had a friend named 'The Professor'.
That made me laugh.
How can you make generalized statements like that? Cross sections vary by many orders of magnitude
Fast neutron cross scattering sections in the couple MeV range barely vary over more than the range of 1-10 barns. Fe56 is about 4 barn over this range. C12 drops off from about 3 barns to 2 barn, hydrogen from 4 to 1 barns, Be9 from 7 to 2, but mostly around 3 to 2.
And being "displaced" is not a fundamental universal material property effect, it depends on how the material responds to radiation damage, which varies greatly.
It is a measure of the environment, and illustrates that fusion reactor walls are in a different ball park than fission reactors. You can't look at fission reactors and say those materials will be fine under a couple orders of magnitude more damage. If you don't like neutron displacements, you can also look at other factors, like hydrogen and helium implantation, which is also typically two order of magnitude higher in fusion blanket materials than in a fission setup.
Generally materials respond better at high temperatures (annealing), and fusion reactors operate of course at far higher temperatures than fission reactors.
Creep and thermal defect issues set upper limits on the materials involved. Additionally, chose of coolant places further limits. Integration of annealing cycles into blanket design is not brought up enough in some design studies, but is a consideration to help. But it is not straightforward and likely unreachable in some designs for some of the components. Reduced activation ferritic/martensitic steels have a limit of about 550 C due to creep issues at higher temperatures, but don't seem much annealing until the 800+ C range. And only some advanced cooling designs are going to allow blankets to even get near that temperature anyway, as water based designs are limited to ~300 and more established helium and liquid metal designs around 500 C.
Blanket design is extremely constrained by tritium breeder ratio to ensure more tritium is produced than used, which squeezes volume allowed to be used by coolant, which leaves very limited volume for structural components. This requires high stress application of materials unlike what you see in any existing fission reactor, and only approached in some performances in proposed advanced designs. Regardless, the operating temperature of the material works out about the same as the temperature range in fission reactors, but they have much lower neutron flux to worry about. Gen 4 reactor designs are in the 500-1000 C temperature range, exceeding in some cases what is thought reasonable for fusion blanket design.
I have trouble seeing how one would consider neutrons per square meter to matter more than neutrons per MeV.
The number of neutrons gets you the number of impurity defects, which can't be removed by simple annealing, especially at the lower temperature ends. Other defects tend to be related to total flux energy, which is also higher (you're looking at multiple MW/m^2/a vs kW/m^2/a range for structural elements). And you can't just spread it over broad areas, because that would greatly increase the reactor size, and to the zeroth order, reactor cost scales with volume.
Some degree of downtime for maintenance is normal in power plants - even "high availablility" fission plans still only get ~85% uptime.
Blanket replacement is considerably more complex than fuel replacement in a fission reactor, and there are concerns that at the DEMO scale, replacement more frequent than every couple years would be devastating, and it is not even trying to make commercial profitability.
I'm not saying these problems are insurmountable, but multiple reports and summaries of the state of fusion research have named material properties as the biggest unknown and potential issue. A dedicated facility is needed to test these materials, because su
1-10 barns is, of course, by definition, an order of magnitude. There is a massive difference between 10 barns and 1 barn. Tenfold, to be precise. ;)
More to the point, you can't just combine all cross sections like that. The energy imparted from an elastic collision isn't the same as from an inelastic collsiion, which isn't the same as an (n, gamma), and so forth. Elastic collisions are particularly low energy, particularly the higher Z the target. Taking them out of the equation yields much greater differences between materials in the range of a couple MeV. The upper end of the neutron energies are "somewhat" similar (up to about one order of magnitude), but down below 6 or 7 MeV or so there's quite a few orders of magnitude difference.
Likewise, total cross sections have no bearing on the accumulation of impurities in the material. The particular cross sections are relevant not only in terms of reaction rate, but also what sort of impurities you tend to accumulate and what effect they have on the properties of the material. Which of course varies greatly depending on what exactly they are.
It's not a side issue, it's a fundamental issue to the design of a material designed for high temperature operation under a high neutron flux.
Perhaps they've been heading in a different direction since I was last reading on the topic, but I was under the impression that a prime blanket material under consideration was FLiBe. Which operates in a temperature range of 459-1430C, and is its own coolant. That doesn't change what the first wall has to tolerate, but as for the blanket itself, you have no "structural properties" to maintain, and cooling is only limited by the speed that you can cycle it.
The last paper I read on the subject also suggested that for breeding purposes one needs not only beryllium (they were reporting really poor results with high-Z multipliers), but the optimum ratio (to my surprise) worked out to be significantly more beryllium than lithium. So building structural elements out of beryllium serves double purpose, you don't have the excuse of "I need to use steel because it's cheaper" - you need the beryllium either way. It's strong, low density, similar melting point to steel, but retains strength better with heat, and highly thermally conductive. Beryllium swelling from helium accumulation stops at 750C+ as helium release occurs. So pairing a beryllium first wall with a FLiBe-based blanket seems like a very appropriate option.
Please don't get me wrong, I'm not at all disputing the great amount of engineering work left to do. I'm just more optimistic that appropriate solutions will be found. Perhaps I'm just naive in that regard ;)
It's times like this I wish I had a friend named 'The Professor'.
1-10 barns is, of course, by definition, an order of magnitude. T
But it is not "many orders of magnitude."
Taking them out of the equation yields...
But then you're taking out the dominant effect. The high energy elastic collisions above keV range is going to cause displacements, at which point it comes down to just total number of impacts. The total cross section for higher energies is plenty for estimating displacement related problems, as the inelastic effects are too much smaller to make much total difference in that regard.
Likewise, total cross sections have no bearing on the accumulation of impurities in the material. The particular cross sections are relevant not only in terms of reaction rate, but also what sort of impurities you tend to accumulate and what effect they have on the properties of the material. Which of course varies greatly depending on what exactly they are.
Which is why hydrogen and helium implantation rates were also mentioned separately, because those are going to be there regardless of what material you use because of the neutrons and potential high energy alphas you have involved (despite the magnetic fields). There are plenty of other effects and transmutation is a n issue too, but the number of displacements scales with the number of interactions you would expect and the number of impurities for a given material in the volume close to the source (as opposed to total number of impurities).
That doesn't change what the first wall has to tolerate, but as for the blanket itself, you have no "structural properties" to maintain, and cooling is only limited by the speed that you can cycle it.
You still need the plumbing to circulate it at sufficient rates that can deal with the pressures and temperatures involved, and possible issues with induced currents from disruptions depending on how much of a problem they will be in advanced designs.
So pairing a beryllium first wall with a FLiBe-based blanket seems like a very appropriate option.
Research papers are still working on many different designs, because they don't know what the long term damage and performance will be. There are people still arguing for circulating water and helium based systems. Some materials will accumulate defects in clusters, and beryllium doesn't do as well with porosity. Pretty much every design I've seen still has some amount of structural steel, with some using steel bonded to beryllium to try to combine their advantages. The first wall itself may have unexpected effects too, as there have been enough surprises about how tungsten basically turns into an open foam under some similar such conditions.
Please don't get me wrong, I'm not at all disputing the great amount of engineering work left to do. I'm just more optimistic that appropriate solutions will be found. Perhaps I'm just naive in that regard ;)
I expect solutions to be found, but not without the research since many surprises have already come up in much less harsh conditions. But the current state amounts to a big unknown, because there is a lot of difficult getting material scientists involved in fusion research. Despite the history of it being pointed out as one of the big things needing to be addressed, it seems to be the last one to get addressed by various programs and funding agencies.
No, there's nothing unfair about the criticism. At all!
You state "we can viably produce fusion power today. The real question [...] is, what is it going to cost?" As though those are 2 different issues! From an engineering point of view, OK yes, they are 2 different issues. However they are fused from any practical/commercial perspective. And therefore when you portray fusion as "viable" today, well no it isn't viable.
When you talk to an average citizen and he's asking, "where's my fusion power?", he's not interested in technology demos. When you talk to private sector backers, she's not interested in engineering samples. When you talk to government decision makers, they are not interested in proof-of-concept tabletop demonstrations. If you ask for funding of a commercial fusion reactor, you better have your ducks in a row! And they aren't in a row, in fact they aren't even close.
Fusion power is still 50 years away because we really don't know how far away it is. No one can tell you when the first commercial demonstration plant will be built. No one knows what fusion technology it will be built with. No one knows how much it will cost. No one knows where it will be built. No one knows how the energy harvesting will be done. No one knows how neutron enbrittlement will be handled. No one knows what the duty cycle of the fusion reaction will be.
In short, the unknowns are still vast. And it reeks of "the boy who cried wolf" when people like yourself claim that somehow, the challenges are small and mere details that can be handled by any engineer with a 2 year contract to do so! This is the problem with fans of fusion. They have repeatedly raised expectations that cannot be fulfilled and it created a big credibility problem.
Stop it! Just stop. Fusion is a long-term research project. If we are lucky, in 50 years we might get our first commercial fusion power plant. Maybe. And if our commercial fission experience holds true, it will be an entire generation or more beyond that before fusion power is seen as a routine, every day possibility. One competitive with other power sources.