The ITER Fusion Reactor: The World's Most Complex Construction Project

Wikipedia:

ITER (initially the International Thermonuclear Experimental Reactor, iter meaning "the way" or "the path" in Latin) is an international nuclear fusion research and engineering megaproject aimed at creating energy through a fusion process similar to that of the Sun. It is being built next to the Cadarache facility in southern France. Upon completion of construction of the main reactor and first plasma, planned for 2033–2034, ITER will be the largest of more than 100 fusion reactors built since the 1950s, with six times the plasma volume of JT-60SA in Japan, the largest tokamak operating today.

The long-term goal of fusion research is to generate electricity. ITER's stated purpose is scientific research, and technological demonstration of a large fusion reactor, without electricity generation. ITER's goals are to achieve enough fusion to produce 10 times as much thermal output power as thermal power absorbed by the plasma for short time periods; to demonstrate and test technologies that would be needed to operate a fusion power plant including cryogenics, heating, control and diagnostics systems, and remote maintenance; to achieve and learn from a burning plasma; to test tritium breeding; and to demonstrate the safety of a fusion plant.

R U looking for a primer on fusion power?

Brian Potter, Will We Ever Get Fusion Power? Construction Physics, June 26, 2024. This is a good one, though a bit long. Potter goes through the history and various methods. From the conclusion:

Despite decades of progress, it’s still not clear, even to experts within the field, whether a practical and cost-competitive fusion reactor is possible. A strong case can be made either way.

The bull case for fusion is that for the last several decades there’s been very little serious effort at fusion power, and now that serious effort is being devoted to the problem, a working power reactor appears very close. The science of plasmas and our ability to model, understand, and predict them has enormously improved, as have the supporting technologies (such as superconducting magnets) needed to make a practical reactor. [...] With so many well-funded companies entering the space, we’re on the path towards a virtuous cycle of improvement: More fusion companies means it becomes worthwhile for others to build more robust fusion supply chains, and develop supporting technology like mass-produced reactor materials, cheap high-capacity magnets, working tritium breeding blankets, and so on. This allows for even more advances and better reactor performance, which in turn attracts further entrants. [...] At least one of the many fusion approaches will be found to be highly scalable and possible to build reasonably sized reactors at a low cost, and fusion will become a substantial fraction of overall energy demand.

The bear case for fusion is that, outside of unusual approaches like Helion’s (which may not pan out), fusion is just another in a long line of energy technologies that boil water to drive a turbine. And the conditions needed to achieve fusion (plasma at hundreds of millions or even billions of degrees) will inevitably make fusion fundamentally more expensive than other electricity-generating technologies. Even if we could produce a power-producing reactor, fusion will never be anywhere near as cheap as simpler technology like the combined-cycle gas turbine, much less future technologies like next-generation solar panels or advanced geothermal. By the time a reactor is ready, if it ever is, no one will even want it.

Perhaps the strongest case for fusion is that fusion isn’t alone in this uncertainty about its future. The next generation of low-carbon electricity generation will inevitably make use of technology that doesn’t yet exist, be that even cheaper, more efficient solar panels, better batteries, improved fission reactors, or advanced geothermal. All of these technologies are somewhat speculative, and may not pan out — solar and battery prices may plateau, advanced geothermal may prove unworkable, etc. In the face of this risk, fusion is a reasonable bet to add to the mix.

There's much more at the link.

Sabine Hossenfelder on the race for practical fusion power

From YouTube:

In this video we survey the biggest and most interesting nuclear fusion startups which want to make nuclear fusion commercially relevant. What are the different approaches, how far along are they, and what are the pros and cons. This video has been in the works for months and it's the longest video we've made so far, almost half an hour, so I hope you have a comfortable seat!

Many thanks to Jordi Busqué for helping with this video http://jordibusque.com/

👉 Transcript and References on Patreon ➜ https://www.patreon.com/Sabine

00:00 Intro
01:35 Nuclear Fusion Pros and Cons
04:37 Approaches to Nuclear Fusion
07:34 Field Confinement, Tokamaks
12:57 Field Confinement, Stellarators
16:19 Field Confinement, Plasma Beams
21:15 Inertial Confinement
24:04 Hybrid Approaches
27:31 Summary
28:20 Learn Physics With Brilliant

Hossenfelder on chaos control [e.g. teaching robots to walk, nuclear fusion plasmas]

You might want to look at this post from February: Using AI (reinforcement learning) to train a magnetic controller for tokamak plasmas.

Fusion, we have achieved ignition! But why so long, and when will it be practical? [Progress]

Kenneth Chang, Scientists Achieve Nuclear Fusion Breakthrough With Blast of 192 Lasers, NYTimes, Dec. 13, 2022.

“This is such a wonderful example of a possibility realized, a scientific milestone achieved, and a road ahead to the possibilities for clean energy,” Arati Prabhakar, the White House science adviser, said during a news conference on Tuesday morning at the Department of Energy’s headquarters in Washington, D.C. “And even deeper understanding of the scientific principles that are applied here.”

If fusion can be deployed on a large scale, it would offer an energy source devoid of the pollution and greenhouse gases caused by the burning of fossil fuels and the dangerous long-lived radioactive waste created by current nuclear power plants, which use the splitting of uranium to produce energy.

Yes! But why has this taken so long? When we set out to create an atom bomb in WWII we had success within a couple of years. In 1960 President Kennedy said we’ll be on the moon within a decade, and we were. A decade later President Nixon accounted an all-out government-funded war on cancer. I suppose we’ve made some progress, but not much, and success is not in sight. Why do some such efforts succeed while others go on and on?

We’ve been working on fusion power since the late 1950s. Why’s it taken us so long to get this far? And we still have a way to go to make it practical. On the face of it would seem that some engineering projects are more complex than others, way more complex. See this post from a year ago, Types of Research, R&D ventures, by ‘guesstimated’ probability of success [Progress].

Later:

Fusion would be essentially an emissions-free source of power, and it would help reduce the need for power plants burning coal and natural gas, which pump billions of tons of planet-warming carbon dioxide into the atmosphere each year.

But it will take quite a while before fusion becomes available on a widespread, practical scale, if ever.

“Probably decades,” Kimberly S. Budil, the director of Lawrence Livermore, said during the Tuesday news conference. “Not six decades, I don’t think. I think not five decades, which is what we used to say. I think it’s moving into the foreground and probably, with concerted effort and investment, a few decades of research on the underlying technologies could put us in a position to build a power plant.”

There’s more at the link.

Why fusion energy is so hard to produce

Practical Fusion power? [more likely than AGI]

Henry Fountain, Compact Nuclear Fusion Reactor Is ‘Very Likely to Work,’ Studies Suggest, NYTimes, Sept. 29, 2020.

Scientists developing a compact version of a nuclear fusion reactor have shown in a series of research papers that it should work, renewing hopes that the long-elusive goal of mimicking the way the sun produces energy might be achieved and eventually contribute to the fight against climate change.

Construction of a reactor, called Sparc, which is being developed by researchers at the Massachusetts Institute of Technology and a spinoff company, Commonwealth Fusion Systems, is expected to begin next spring and take three or four years, the researchers and company officials said.

Although many significant challenges remain, the company said construction would be followed by testing and, if successful, building of a power plant that could use fusion energy to generate electricity, beginning in the next decade. [...]

“Reading these papers gives me the sense that they’re going to have the controlled thermonuclear fusion plasma that we all dream about,” said Cary Forest, a physicist at the University of Wisconsin who is not involved in the project. “But if I were to estimate where they’re going to be, I’d give them a factor of two that I give to all my grad students when they say how long something is going to take.” [...]

H/t Tyler Cowen.

A comment I left over at Marginal Revolution:

It could be a game-changer for the world's energy future if it works. If have no serious opinion about whether or not it will work, but note, as the article says, that we've been chasing fusion power for a long time, since before the Apollo Program and the War on Cancer.

Apollo, of course, came through. It never really was a "moonshot" if by that you mean a low probability enterprise with a potential for high gain if it succeeds. It was expensive and dangerous, some men did lose their lives, but the basic science was in place from the beginning. It just took a lot of engineering.

The war on cancer was and is different. The basic science wasn't in place and it seems as though it still isn't. We've learned a lot over the years, but not what we need to effect routine cures.

As I say, I don't what what the case is for fusion. It seems that the science is there , but the engineering is very difficult.

And then we have human-class AGI, or even super-intelligent AGI. I'm with those who think we're missing basic a lot of science and the goal is mostly a phrase with no coherent meaning. Yes, we've got chess and Go down cold, and machine translation is impressive, but you wouldn't use it for legal documents. GPT-3 is interesting and impressive too. But I think that line of development will bottom out before GPT-X consumes all the electrical power in Northern California.

We'll have practical fusion power before human-class AGI.

* * * * *

Useful commentary thread on Twitter:

People are still tweeting about the NYT's piece on the SPARC nuclear #fusionenergy release, so as a fusion PhD student I'm going to explain what it is and isn't...

🧵https://t.co/cqRe3fsAx1

— Tom Nicholas (@TEGNicholas) September 30, 2020