Japan’s JT-60SA fusion reactor project announced first plasma in October of this year to denote the successful upgrades to what is now the world’s largest operational, superconducting tokamak fusion reactor. First designed in the 1970s as Japan’s Breakeven Plasma Test Facility, the JT-60SA tokamak-based fusion reactor is the latest upgrade to the original JT-60 design, following two earlier upgrades (-A and -U) over its decades-long career. The most recent upgrade matches the Super Advanced meaning of the new name, as the new goal of the project is to investigate advanced components of the global ITER nuclear fusion project.
Originally the JT-60SA upgrade with superconducting coils was supposed to last from 2013 to 2020, with first plasma that same year. During commissioning in 2021, a short circuit in the poloidal field coils caused a lengthy investigation and repair, which was completed earlier this year. Although the JT-60SA is only using hydrogen and later deuterium as its fuel rather than the deuterium-tritium (D-T) mixture of ITER, it nevertheless has a range of research objectives that allow for researchers to study many aspects of the ITER fusion reactor while the latter is still under construction.
Since the JT-60SA also has cooled divertors, it can sustain plasma for up to 100 seconds, to study various field configurations and the effect this has on plasma stability, along with a range of other parameters. Along with UK’s JET, China’s HL-2M and a range of other tokamaks at other facilities around the world, this should provide future ITER operators with significant know-how and experience long before that tokamak will generate its first plasma.
fusion has been 10 years away since the 60’s. And will be 10 years away when I buried..
That said, plasma research is a good thing to be doing..
“And will be 10 years away when I buried..”
Just curious, but, how old are you now?
As long as you stay 10 years away from being buried, it’s good
Didn’t someone once say “Fusion is the power of the future and always will be.”?
I still worry about waste heat. In most power plants, even nuclear ones, the best you can hope for is about half as many electrical watts as your thermal input. Which means that the plants produce as much waste heat at the plant as the total heat that the customer loads produce. But with current fusion power technology being no better than 1% efficient, that means that the plant produces 99 Watts of waste heat for every Watt delivered to customers. And everybody acts like the efficiency doesn’t matter because fusion energy is practically unlimited. It seems like this should be a concern.
The next concern is waste products. Anti-nuclear people point at radioactive by-products with long half-lives, but so far, it seems like nobody has figured out that fusion is NOT without by-products. Am I wrong? I’d like to be wrong.
It seems like if we’re still afraid of fission power, we really should be putting more work into that as we’re putting into fusion.
The current thinking of recovering energy is a liquid lithium curtain around the tokamak which catches the produced neutrons (~80% of the reaction energy) -> heat exchanger -> steam -> turbine. The Lithium would also be used to breed tritium fuel.
If and when we crack fusion energy, I believe there would be research into recovering energy through inductive coupling with the plasma.
RE: waste products, the results of deuterium/tritium fusion is helium and a neutron. In the event of catastrophe, the fusion reaction would rapidly and boringly just stop. The very small amount of tritium in the reaction chamber may be released, half-life about 12.5 years. Fuel and neutrons would be contained within the building, as per existing buildings regulations for radioactive activities.
Source: Worked in fusion for years.
There is more to plasma research than using fusion reactors for commercial power plants.
While fusion releases some high energy particles like neutrons, the material left over is the fused fuel, in the case of hydrogen that would be helium. Even if the helium ends up radioactive, the half-life is ages lower than something like plutonium or cesium would be.
The only dangerous phenomenon IMO is neutron activation, which can leave surrounding materials radioactive. But doesn’t that happen on fission reactors as well? Their working principle is the release of high energy neutrons
Where do you get that number from?
There are no power producing nuclear reactors in existence, so speculating on efficiency is meaningless.
Fusion reactors, that is. There are certainly power producing nuclear reactors, but no fusion types yet.
thermal pollution will be a problem for the post fusion world. i mean you have to deal with waste heat now, even with renewables, in one way or the other. any efficiency < 100% results in waste heat.
of course when you want to build a world where everyone can have the ac set to 60 in the summer and the heat set to 80 in the winter and can take 3 hot showers a day and drive 50 miles for a big mac., its gonna have some cost. that level of energy will cause significant waste heat.
Humanity uses about 20 terawatts of power.
Sunlight is 174 petawatts. The amount of primary energy we use and the heat we produce is roughly 0.01% of that. Even if we were using ten times as much, it would still be practically nothing.
“Thermal pollution” is only an issue of how to disperse heat effectively, so you don’t end up boiling the lake or other small body of water next to your fusion power plant.
Heater set to 80? Is that you, Pop Pop?
If I am remembering what I was told by a friend in the nuclear field correctly smashing two hydrogen atoms together ( fusion) produces deuterium (the second isotope of hydrogen (not radioactive) and smashing deuterium atoms together produces helium (also not radioactive). Tritium on the other had is radioactive, so there is a concern there.
Waste heat is only waste if you don’t use it. Nowadays most modern thermal power plants dump a large part of their “thermal waste” into district heating systems or other industrial plants. So this problem has already been solved and even extending capacity and range by an order of magnitude would be a rather simple affair with existing technology.
The fusion “first wall” will become neutron-activated. How often will this be necessary to replace? Won’t the entire magnet system need to be disassembled for this?
The SPARC reactor design has superconducting windings that can be opened, allowing the reaction vessel to be periodically replaced as a unit. Otherwise you’d need to climb in there and dismantle it piece by piece.
As for how often, something like 5 years due to neutron embrittlement sounds about right
As far I know current idea is that the commercial reactors after ITER will have liquid metal (lithium) flowing, pumped by magnetic fields, on the inside of the coils capturing the neutrons. Liquids have not the neutron embrittlement problem. And the interesting thing is that if you use lithium, reactions with neutrons produce helium isotopes same as in the fusion reaction inside so there already needs to be mechanism how to get rid of them.
>the new goal of the project is to investigate advanced components of the global ITER nuclear fusion project.
ITER was supposed to be about testing the components for later commercial fusion reactors, but as always, the other reactors keep getting built faster than ITER with a fraction of the funding, so the goalposts are moved to the point of reversing them.
Exactly the same difference as making gunpowder at home and making a ammunition factory. ITER is the factory design test. JT (and others) are the homelab that’re making the recipe for ITER to consume.
ITER is a boondoggle. It was supposed to be the testbed for technologies so you could then later build the DEMO reactor, and THAT is the factory design test, but it seems the smaller projects are getting results faster while ITER is just dragging feet and sucking up money and researchers from other institutions and fusion devices, preventing them from scaling up.
ITER was supposed to be about bootstrapping the fusion industry, but now everyone is waiting on ITER to do something – anything. It’s going to be another 12 years before it will actually get ignited. That’s the official timeline.
>Since the JT-60SA also has cooled divertors, it can sustain plasma for up to 100 seconds
Wendelstein 7-X is doing 8 minutes of plasma now.
https://www.ipp.mpg.de/5322229/01_23?c=5322195
That’s apple and orange comparison. JT60SA wants to sustain fusion-level plasma for 100s. Stellerator W7X only supported heating (and sustaining) a hot plasma for 8min. No fusion occurred, this test was for validating microwave heater and cooling system.
you usually use hydrogen for testing so it wont fuse and so there is no radiation (from neutron activation mainly) to deal with. this makes regulators happy and keeps the machine clean to work on. once they got it operating in spec, then they order their deuterium and tritium. you put the right fuel in and your neutron counters start ticking even if your fusion rate sucks. you want the thing spewing neutrons at some point because that’s how you get the heat out and breed tritium.
reactions that do not produce neutrons exist. those come with other advantages like direct conversion to hvdc, and you can ditch the steam engine entirely in some cases. but this comes with a much reduced cross section so fusion is a lot harder to achieve requiring higher plasma temperatures. you got to walk before you can run. i figure these will be third and fourth gen designs and we dont even have gen1 yet.
No fusion will occur with the JT60SA either. They have no facilities to deal with tritium, and the conditions in the plasma aren’t sufficient to ignite deuterium alone, so all they can ever do is dry run it.
Why not use the heat that is wasted to boil water or something I don’t understand why that heat can’t be collected then used to turn a steam turbine or something?
If it will boil a near by lake as one person said up there why not use that heat as the power source? I don’t understand how it can hypothetically do create heat that can’t be vented directed and harassed. Would someone please explain why to the people like me who are a little nuclear challenged thank you.
It’s not really nuke-specific but I have a relevant explanation for the future. Heat engines are what you call things that take heat in, get useful work out of it, and output what’s left over at a lower temperature. If it turns out that after these guys have gotten what energy they can from the reactor, they’re left with a whole lot of warm but not incredibly hot water, it’s not very useful.
There’s limits to anything that harnesses heat which are decided by physics. They say that if the input temperature is very close to the output temperature, then no matter how good your engine is, only a very small fraction of the input heat will actually turn into useful work, and all the rest will just pass through and come out the other side at a cooler temperature. If you’re using a lake then the cold side can’t be any colder than the lake itself.
That being the case, if you have a whole bunch of warmish water, it might be warm enough to quickly evaporate without being hot enough to get more than a tiny percentage of electricity out of it no matter how much expensive equipment you try to use. So the thing to do is to forget about getting much useful power from it and instead just try to cool it down enough not to evaporate the lake. Which is still annoying, if there’s a huge amount of water, but doable.
The Texas A&M campus in College Station uses the heat from the on site CHP plant for heating and hot water. It produces more than they use, so some neighboring buildings also get “free” hot water. (I suspect it’s only hot water as heating is only needed for a short time during the year in that area while hot water is needed year round, upsizing the plumbing to handle that would increase cost and reduce the number of buildings that could be serviced.)
Except the utility service charge is really high at $40/month for a one bedroom apartment, on top of the usual electricity use charges. (That was in 2009-2011.) Not sure if that’s still the case, it would be cheaper for students to go off grid nowadays…
Yeah, if you can arrange to do that it can help. Though as a college campus, it’d be much easier if they used the hot water for their own buildings and dorms rather than work with the nearby apartments, I would think.
I’m ignorant but did work in petro-fuels for a while. In that case flare off byproducts because it wasn’t economical otherwise.
I’d guess that unless a lake was in the middle of a city and a fusion reactor also in the middle of a city, (ha!) pumping steam pipes around for direct heating wouldn’t be economically viable. And pure speculation as well, but harnessing the other waste heat wouldn’t return profit over the cost of building the extra low pressure turbines etc.
Mostly because it is a research facility. They focus on specific questions – how to use warm water is not one of them.
As a heat source, this lab would be “unreliable” with a low average power output (because you’ve got a 4 week maintenance ongoing) and suddenly you need 41 MW of heat to be removed for 100 seconds.
Basically that’s all they do but fusion is about creating a self sustaining reaction from which we can harness that heat/energy without slowing or stopping the reaction.
Fusion is about trying to harness the natural heat from natural reactions that are easy to “control” and safe to be around. Fission is not altogether safe, either is fusion, but it is more effective. Would be great for spaceships where heat can move you and also easily be displaced by changing angles on plates and sinks to dissipate unissued thermal energy.
Want net gain fusion? Find a nuclear bomb expert.
Hopefully someone will figure out how to introduce gaseous lithium, dilithium crystals, into the mix so we can get those starship engines built soon.