This video details some of the ways that nuclear fusion energy reporting gets done (both media, but also the industry) : https://youtu.be/LJ4W1g-6JiY
We are not near a viable fusion reactor yet. Not close.
We are not near a viable fusion reactor yet. Not close.
Thus, hot-neutron fusion is a dead end. It might be that things learned chasing hot-neutron fusion will turn out to be useful for something else, such as aneutronic fusion. But work on aneutronic fusion, itself, would be overwhelmingly more useful. Very little work is being done on aneutronic fusion.
The fact that a fusion test reactor hasn't done this yet is a flimsy point. A burning plasma test machine hasn't even been made. How would you propose blankets and shields be demonstrated if not in a burning plasma machine?
At enormous cost. Nobody even has a plan for a way to operate a fusion plant at anything close to matching fission's cost, and fission itself gets less economically competitive with each passing day.
If a fusion plant could be operated competitively, surely running the same energy collection system wrapped around a fission pile would do just as well, and thus better than existing fission plants? Try it and see!
And what of renewables? We couldn't run our society on wind and solar while still feeding everyone with the land we have without displacing millions. Even if we did, the total effort (cost) to society to build and replace terra scale machine arrays would be incredible.
Fission offers a much more dense path. But what of the proliferation and accident concerns? If you set aside quarterly profits just for a moment you might see a path for humanity to stay on its current industrial path if it takes its medicine and solves its energy crisis.
Furthermore, there is never any need to devote space exclusively to solar panels. They coexist well with buildings, where their shade extends the life of roofing material, with parking lots, where they protect cars from damaging sun, with canals and reservoirs, where they reduce evaporation, and with pasture and crop land, where they increase yield by reducing heat stress, and cut irrigation demand by reducing evaporation.
I hope you will choose in the future not to propagate falsehoods you have already been corrected on.
It has also been explained that energy from renewables is radically cheaper than from nukes. So, if building out solar were too expensive, building the nukes for the same output would be overwhelmingly moreso. But in fact cost for renewables and for storage is still in free-fall, so nukes of any sort get less competitive every day.
I think on paper, you're right that fission ought to be more commercially viable than anything any of the fusion people will be able to achieve any time soon, but I think there's at least a chance that fusion technologies will manage to get themselves regulated in a way that makes the all-in costs of fusion projects much more manageable, even if the reactor itself is more expensive, less power-dense, etc. In an NRC roundtable discussion last week, there was discussion suggesting that much of the need for, say, handling tritium, could be regulated under existing, relatively lightweight regulatory structures already in place for things like nuclear medicine waste, and it seems like both the US and UK energy regulatory authorities are pretty interested in building streamlined regulatory structures that make fusion much more approachable than fission historically has been.
Much of their cost overburden arises from corruption tax, a problem common to public works projects massively expensive enough to need buy-in from a wide range of stakeholders who then expect patronage, to be charged to extreme cost overruns and schedule slip.
Since no nuke plant has ever been built with private money, and there is no realistic prospect of one ever being built with only private money, this overburden will be lifted only when corruption has been suppressed. Then we will still have the enormous, foreseeable decommissioning cost, the very high operating cost, and the astronomical liability subsidy always omitted from cost figures, but charged to the general public.
This statement is not necessarily universally true. In particular, if one can convert the fusion energy to electricity with high efficiency (i.e., not by an ordinary thermal cycle as would be needed for the neutron energy in a DT fusion reactor), and if one could also recover the input energy to the plasma with high efficiency, then it could be practical to have a much lower Q.
Helion's scheme is like this. I understand they've demonstrated 95% recovery of plasma energy (no fusion occurring, just heating and compressing the plasma, then recovering that energy to capacitors), which is rather impressive. Their commercial 50 MW concept would have Q = 2.
Helion is the fusion company I feel most positive about, for that and other interrelated reasons.
What it ignores is that tokamak output is highly nonlinear. It scales with the square of plasma volume, and the fourth power of magnetic field strength. Double the field, 16X the output. These scaling laws are very well established at this point.
The plasma volume scaling is why ITER is so big. But after ITER was designed, people invented REBCO superconducting tape, which can support much stronger magnetic fields and is commercially available.
Using those fields, CFS is building their SPARC reactor, which will get ITER-level output (Qplasma=10) from a reactor half the size of JET, which was built in four years. (Three years for the building, one year for the reactor inside.) If that goes well, the next step would be build their ARC reactor, which will be the same size as JET and get commercial-level output.
(Some of the alternate designs also have great scaling in theory, but we don't understand their plasma physics as well so it's harder to predict how they'll turn out.)
> "HB11 Energy’s research demonstrated that its hydrogen-boron energy technology is now four orders of magnitude away from achieving net energy gain when catalyzed by a laser," reads the press release. "This is many orders of magnitude higher than those reported by any other fusion company, most of which have not generated any reaction despite billions of dollars invested in the field.
> HB11 claims is a "world-first 'material' number of fusion reactions by a private company
So they have a result which is 10x better than they thought will be, but still way lower than stellarator etc.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8791836/
Edit: Wikipedia suggests that they were using a different method to calculate Q, only measuring the power input to plasma vs output from fusion, not including system losses. So that figure is probably not directly comparable.
> the NIF used ~477 MJ of electrical energy to get ~1.8 MJ of energy into the target to create ~1.3 MJ of fusion energy
https://en.wikipedia.org/wiki/National_Ignition_Facility#Bur...
It's interesting, at that scale. But just imagine if someone designing a power plant said that their reactor generated 10x the power calculated.
Neat, at that scale. But very strong spin.
MCF is quite close to triple product performance of a burning plasma, where self-heating becomes dominant. There is a financial hurdle going from a research device to a nuclear machine capable of burning plasma. People are doing it right now though.
"Durability is still a big concern" translates to "but it doesn't help, in the end."
I think we know that they will work, once they actually work.
And the main important question remains, if they will also work economically.