Fusion reactors

How close are we to viable fusion reactors?

http://www.theguardian.com/environment/2016/feb/03/nuclear-fusion-germany-scient...

https://www.technologyreview.com/s/600712/experimental-fusion-reactor-switched-o...

I sure hope we're close. But after hearing the promise and the failures for decades, I long ago decided not to hold my breath. On the the hand, I have no doubt success will be had eventually. Now? I dunno.

Stellar, I remember my excitement over the first article about cold fusion. : )

Anyway, I met a man this morning at the gas pump and he started telling me about fusion reactors. I asked how they achieve the necessary temperature and he started describing the Tokamak device.

https://en.wikipedia.org/wiki/Tokamak

When I got home I searched a little to find the linked and many other articles. It looks like at least progress is being made. I had not been aware we were anywhere close to reaching fusion temperatures.

Interesting about the gas station guy. But I remember excitement over the Tokamak design in the '70s. The same conversation might have been had 40 years ago.

I'm sure at least some of you have heard the saying: Fusion reactors are only twenty years away -- and always will be.

I recall a reasonable amount of media coverage when this stellarator in Greifswald was completed in the fall. I read this from the BBC, and Science has a more detailed piece that seems to be freely available.

I'm more familiar with tokamaks and laser-driven inertial confinement fusion (ICF) than with stellarators, so I'm not sure how seriously to take suggestions that the recent progress in Greifswald "could mark a turning point" and "might save nuclear fusion" (both quotes from the Science article linked above). This new 'Wendelstein 7-X' machine cost ~$1billion and seems much less ambitious than the world's flagship tokamak and ICF facilities. The ~$20billion tokamak (Iter, currently under construction in France) aims to produce ten times more power than it needs to run, while the ICF facility (the National Ignition Facility, NIF, in California) attempted to produce as much power as it needed to run. (In all these cases, the power produced isn't being captured for electricity, just measured to assess the technology.)

Of course, Iter has been an organizational fiasco (here's a small selection of press coverage) and NIF's 2009--2012 National Ignition Campaign failed. (NIF has made some progress since then, but its main focus has shifted to weapons and its successor energy project has been cancelled.) So stellarators may end up the best by default...

That said, I remember reading something a couple of years ago about yet another alternative being explored, which also needs to catch up to the main technologies but might become competitive in the future. Let me see if I can track it down... Ah, it was the Magnetized Liner Inertial Fusion experiment at Sandia, which only costs ~$5million per year but "still falls well short" of producing as much power as it needs to run. I can't find the article that I recall, but this one should suffice for the curious.

The article I linked had the French tokamak at $50 billion. Perhaps rrp is right about that one. : )

daschaich,

I missed the announcements in the fall. But for the guy at the gas station today I would have missed this announcement from Germany.

I think I will go back to the good old days of wishing for cold fusion. : )

Possibly of interest...

Good News for Stellarators: New simulations of an alternate fusion reactor design reveal that it can be stable against turbulent fluctuations.

The research article itself also provides a popular summary of its own.

So, maybe in 20 years or so?

Two weeks.

For my money, the one to watch is the late Bussard's (of "Bussard collector" Star Trek fame) Polywell reactor. This presentation from 2012 is still riveting: Bussard's Google Talk The past few years have seen Bussard's successors quietly iterating the engineering with funding from the Navy. The discussion hub for the technology is here.

"We spent $15 billion dollars studying tokamaks, and what we learned about them is that they are no damn good." --Bussard, Google Talk, 2012.

The other stability question about fusion reactors is their release of ionizing radiation into the environment. Fusion reactors are often thought of as being a totally clean power source; they aren't. Lower levels of various kinds of ionizing radiation are emitted by fusion reactors.

>11 MaureenRoy: But compared to the alternatives how dangerous are they?

Guido47 and everyone, all forms of nuclear power represent the most controversial form of technology that has ever been under development. The main reasons for that controversy include its gargantuan costs, which are encountered throughout the nuclear cycle, its many problems with design, construction, maintenance, decommissioning, a range of nuclear disasters, and questions about permanent nuclear waste storage, as well as a large number of never-resolved human safety questions.

While fusion reactors remain in the development stage, US nuclear reactor technology has been a mature technology for many decades, yet the US nuclear industry continues to seek government subsidies ... hmmm.

The only US reactor that never had safety problems was US Admiral Rickover's demonstration Shippingport nuclear power plant, which was built underground for safety reasons, at Rickover's insistence.

The international radiation safety experts use radiation exposure standards developed 100 years ago, during the 19-teens and 1920s. That time period was decades before the discovery of DNA, which has since been proven to be uniquely vulnerable to ionizing radiation. Yet those radiation exposure standards have never been updated.

>13 MaureenRoy: - in absolute terms far more people are killed mining coal than die from any form of fission reactor incidents. Add in climate based excess deaths and coal is massively worse. Fission is relativity safe and fusion likely much safer still. Not 0 risk but nothing is.

However the full sums as to whether either form are actually 'greener' than coal - or more importantly hydro/solar/wind etc - can't be determined until the collective 'we' have decided what to do with the waste at end of life. I'm unconvinced they're necessary and that the aim should be for much less energy consumption all around, and that that is used to be from solar/wind/hydro rather than nuclear.

>14 reading_fox: And the price per kWh electricity should also be considered. I find fusion reactors a fun research goal, but I don't expect them to ever deliver cheap energy.

Nuclear installations outside of Earth's orbit will also need regulations and safety inspections, since almost all nuclear installations proceed with safety assumptions that are nowhere near adequate:

https://www.space.com/rolls-royce-funding-microreactor-moon-base

A nuclear radiation remedy is being tested at the US National Institutes of Health:

https://www.nih.gov/news-events/news-releases/first-human-trial-oral-drug-remove...

It will take over a year of testing before the US FDA can even begin to review this clinical trial data for drug approval, but the pressure to do so is on, since this drug can also remove lead contamination from the human body. Preliminary evidence shows that human levels of important trace minerals remain intact after use of this new drug. If so, that puts it far ahead of zeolite, a trace mineral-leaching supplement for removal of ionizing radiation from the human body. In the US, zeolite is currently being sold mostly thru extremely expensive multi-level marketing schemes.

>17 MaureenRoy: With Putin’s maniacal nuke ‘em threats we might need that solution soon. Last I heard he had planted explosives in the captured Ukrainian nuclear plant.

As of July 5th, 2023, Dr. Edwin Lyman, a US physicist + leading member of the Union of Concerned Scientists, commented on Twitter that the explosives placed on the roof of the Zaporizhzhia NPP in Ukraine, with 5 reactors, are not actually in a position to cause much damage. But Dr. Lyman previously admitted to being very concerned about the risks to that NPP's location in a war zone.

24 hours later, the news from ZNPP is not good, via Twitter:

Edwin Lyman @NucSafetyUCS
·
2h
Energoatom has just issued a very troubling message about deferred maintenance issues at #ZaporizhzhiaNPP Unit 5, which has been in a prolonged state of "hot shutdown." The Russian operator now plans to transition Unit 4 to hot shutdown as well.

bnielsen and everyone, an important update on fusion reactor technology:

https://www.giantfreakinrobot.com/sci/fusion-breakthrough.html

>21 MaureenRoy:, while that article was published just a few days ago, this MIT achievement appears to have happened in 2021, making it old news: https://news.mit.edu/2021/MIT-CFS-major-advance-toward-fusion-energy-0908

However, it indicates we may have something to look forward to next year: "With the magnet technology now successfully demonstrated, the MIT-CFS collaboration is on track to build the world’s first fusion device that can create and confine a plasma that produces more energy than it consumes. That demonstration device, called SPARC, is targeted for completion in 2025."