Joint European Torus experiments end on a 69 megajoules high The Joint European Torus (JET) has bowed out with a final hurrah by setting a world record in energy output. The UK-based JET began operation in 1983, and the results announced yesterday represent the facility's swansong as it transitions into repurposing and decommissioning. In its final deuterium-tritium experiments, JET …
Fairly sure I have some of the early publicity handouts for JET inamongst the huge pile of stuff I was sent by the likes of CEGB, BNFL et al after writing to them all asking for info for a school project back in the late 80's, because it's been one of those projects it feels like I've known about pretty much my entire life.
So it's something of a bittersweet moment to see it being decomissioned, yet still able to produce some world-beating results in the process, and wholeheartedly agree with you that all who worked there over the decades should be immensely proud of what they achieved - have one from me too...
Yes, but 36 cups of tea in 5 seconds!!
or (if you excuse the non-standard units), 19.17kWh in 0.00139 hours, or 13.8MW. Pretty good for an experimental reactor, and even at a 10X scale would be useful power.
Of course the trick is self-sustaining the reaction indefinitely, but AFAIK 5 seconds is a huge time in nuclear reactions, and scaling up from there is thought to be relatively easy
"creating more energy from the reaction than you need to start it will happen almost by definition once the reaction is sustainable"
This. Sort of like you need some battery power to start an ICE but once the engine is started, it can run for as long as you can feed fuel in (theoretically almost indefinitely), and you have plenty of excess energy that can top up the battery with whatever energy was used to start the engine in the first place. In the case of fusion, though, there is a very very high containment cost (so 'sustainable' is not exactly a given, and it also complicates continuous fuel feed), and the excess power needs to be quite high in order for energy break-even to happen within a reasonable time, because the energy cost of first ignition is also gigantically high.
Not quite as simple as even that. The diference is that for an internal combustion engine the primary starting input is momentum, the primary output is momentum via the same channel, thus the whole cycle naturally repeats - ignore fuel pumps and spark ingnition, or argue we're talking about a two stroke diesel.
A fusion reactor requires a large electical input, among other things to power those magnets, but delivers its output as heat. That isn't the same funamentally self-sustaining property, and conversion from heat to anything else is generally inefficient even 200 years after Carnot.
Good point.... I guess since heat >> electricity conversion is at best 50% as in combined-cycle gas, the fusion reaction needs to consistently generate at least double the heat energy as is needed for ongoing running (mostly magnetic containment). More realistically, I would expect a factor of at least 4 is needed. But I hope that the boffins working on this would have thought of this already!
You mean like a maglev train weighing a humungous 0.2 milligrammes?
The problem is not scale, it is stability. The fields induce plasma currents which screw them up in return, so you have to faff around stabilising them with auxiliary fields faster than they can screw up. Never, ever look at the equations or your brain will destabilise even faster.
"Imagine magnetic fields strong enough to act like gravity on everything around them."
Even a completely wimpy magnetic field from a tiny magnet can overcome the gravity of the entire earth pulling the other way. Fusion containment magnets are orders of magnitude stronger than ordinary magnets, and many many orders of magnitude stronger than gravity
36 cups of tea in 5 seconds. Now there's a kettle!
As they're no longer using JET, can I have it? I'll need to get a bigger teapot to go with it, which won't fit in my old tea cosy - so it's going to require some significant capital outlay. But worth every penny!
Anywone for a cuppa?
> and even at a 10X scale would be useful power
(Depending on what efficiency you can convert it back to electricity of course)
Unfortunately, the main thing JET has proved, over decades of trying, is that we're unable to make D-T plasma fusion work on a small scale - even experimentally, let alone commercially.
There are hopes pinned on the huge-scale ITER being able to do better, but it seems to me there are two possible outcomes:
1. ITER also fails to be stable and self-sustaining. Or:
2. ITER *can* be made stable and self-sustaining. However, this means that any commercial reactor would be at least equally huge and mind-bogglingly expensive, with massive running costs (due to, for example, the reactor vessel becoming highly radioactive from the neutron flux - not to mention the cost of the fuel).
Even case (2) does not bode well for the "clean and cheap" power which we we promised.
There is a large, stable fusion reactor positioned only 8 light-minutes away from us. Why not just capture the power from that?
Or case (3) which is that lessons learnt from JET and even simply building ITER, plus discoveries in materials science over the last 10-20 years allow us to build something with the capacity of ITER at a much smaller scale. I can't remember the name but there is an offshoot of MIT building an experimental tokomak using magnets made of quasi-room-temperature-superconducting material, which allow the same containment power in a much smaller and less complex unit.
ITER is a test reactor. This means it is several orders of magnitude more expensive to build than a commercial fusion plant of the same size would be, because it needs to be able to try out and carefully measure a huge array of different options.
Now, it might prove that none of the options are viable. Or it might prove that self-sustaining is actually very cheap if the vessel is sufficiently large.
Most things get far, far cheaper in bulk - it'd be impossibly expensive to ship a single banana into the UK, yet your supermarket is full of their radioactive goodness.
But no matter what, humanity will have learned a lot of science and proven a lot of technology that will be useful in other places.
Sounds like the final experiment suggested that, despite much criticism, ITER could be on the right track. There is now quite a bit of VC money sloshing around in various fusion projects, all of which seem to suggest that it can be done easier and cheaper than anything the bureaucratic boffins in Toulouse can come up with. And yet, and yet: record energy release and nearly record reaction length.
I think, that as with many things, we may need to go all the way with ITER and then work backwards when it comes to doing it better and cheaper.
Of course, I'm going to put another layer of foil on the house: you can never be too careful!
The issue is that it "still could be on the right track" - as it was 20 years ago! 2035 onwards will indicate whether that's still the case or whether we'll be waiting until 2045 to see whether we can both produce commercial quantities of energy and produce it economically, then 2065 before we have half a dozen plants in Europe the with the output of Sizewell ... Can't help feeling that it's an incredible science experiment but will not have a commercial future ...
At the moment, we should be ploughing government money into a bucketload of solar farms where it's sunny, a bucketload of windfarms where it's windy, a bucketload of tidal plants where it's err tidally and some massive interconnects to distribute it across political boundaries.
My point is that this most recent experiment validates much of what ITER will be doing. Ie. while the dates of the various stages will no doubt continue to slip, it does look like we will no longer forever be 20 years from practical fusion. This stuff is hard™ but the experiments have been getting more successful.
And, please don't play fundamental research projects like these off against industrial policy: it's not an either/or world. Of course, we should be investing in renewable energy and the massive amounts of associated storage.
I think you’re joking, but in case you are not:
Foil won’t protect you from the explosion if you live close enough to ITER for a chemical bang to be a concern (~ a mile). Anything further, you’ll be fine with the brick or wood or whatever is in your walls… this is why this type of Fusion is so appealing, even if it could runaway (which it can’t), then only thing coming out is heat and alpha radiation, which can barely survive transmission in the atmosphere for more than a few meters
> then only thing coming out is heat and alpha radiation, which can barely survive transmission in the atmosphere for more than a few meters
There's the small matter of neutrons. Either they'll leave the reactor, or they'll be absorbed by it (making it radioactive). The latter is not a danger to people living nearby, but a danger to anyone who is involved in the plant maintenance.
What I find sad about European Science and Engineering is - lack of project management. Why shut down a massively successful program BEFORE the next stage is up and running? What happens if ITER is not ready in 2025? It parallels Ariane's dumb, dumb decision to stop Ariane 5 BEFORE Ariane 6 was remotely ready to fly - I actually was in Florida to see the ESA EUCLID launce using SpaceX coz of this dumb management. The US guy giving us the spiel could hardly stop laughing at the idiocy of the Europeans. I shit you not! Lions led by donkeys indeed!
Aren't there far simpler ways to use the heat of the Sun or the World's interior to raise steam and spin turbines.?
I'm all for nuclear fusion research, but hope it can do rather more than just raise steam.
Could it generate exotic isotopes , new subatomic particles or new elements?
Isn't pushing the limits of experimental parameters an end in itself?
It's been a year or two since I had a look at what was happening in geothermal, but AFAIK the industry is moving in 2 directions... one is extended municipal-level, relatively shallow drilling for 'low-quality' heat, which allows municipal heating and water heating, but not hot enough to efficiently power electricity generation. The other is deep-drilling to 'high-quality' heat (allowing electricity generation) in areas that are not volcanically/tectonically active (in theory, anywhere in the world). Both paths are, perhaps ironically, opened up by new drilling techniques evolved for fracking, which allow cheaper drilling.
The idea is to eventually have(many, smaller rather than few bigger) geothermal plants situated away from dangerous hotspots. Either way, I am a fan of 'all of the above' approach to energy. Solar, wind, batteries, geothermal, fission and fusion.... all or required on different volumes and timescales.
People's insistence that since technology A won't immediately solve all of humanities problems for evermore and it's therefore useless and shouldn't be looked at is the most irritating thing.
You're right - all of the above (excluding FF) is the way to go.
I remember reading in the Meccano Magazine how the ZETA project would mean free energy for all within 10 years. That would have been in 1957 (sited at Harwell, right next door to JET). I also spent a week at the JET site once helping them with some computing stuff (they bought Norsk Data minicomputers). Hard to believe it was 40 years ago.
Still waiting for that free energy.
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