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The fusion energy dream is inching toward planet-saving reality
- umvi 7y agoWhat's the "meltdown" equivalent of fusion? What is the worst thing that could happen given unlikely sequence of failures? Is it possible it would go from controlled fusion to uncontrolled fusion?
- chubs 7y agoThe main problem being tackled is trying to get fusion to remain 'alight' - i think if any of the containment systems fail, it simply extinguishes immediately. Not a physicist, though :)
- WalkingMedium 7y agoThere isn't enough fuel in the reactor to create something even close to a meltdown.
- DennisP 7y agoIt's hard to get fusion to happen at all. If something goes wrong, it just means fusion stops happening.
- petschge 7y agoThe energy content in a fusion reactor (even at the 3 GW output scale) is only a few mega joules, or in other words a few sticks of dynamite. Enough to damage the wall. Maybe enough to break the vacuum vessel. At that point the air would stop any further fusion. You might release radioactive tritium, but nothing else that should be felt outside the building. For comparison: The total inventory of tritium would be about 500g, about 50 times the amount of tritium released by fukushima, but the other radioactive isotopes that got released there (caesium, iodine, tellurium) that are much more problematic biologically would be missing.
- radicalbyte 7y agoOnce containment fails the energy which is within the reactor escapes and the reaction stops. Fusion only occurs at these insane pressures/temperatures which won't be maintained if containment fails. I wouldn't want to be in the building when it fails. If it uses Tritium then that's going be an environmental hazard (it's radioactive and will get everywhere). To be honest it's all conjecture right now because we don't have a viable reactor design and failure modes will depend what exactly we build.
- CodeWriter23 7y agoHalf life of Tritum is about 12.5 years, much more favorable than elements used in fission reactions.
- radicalbyte 7y agoTrue, but on the other side if it gets into the water system in any significant quantities then that's going to a bad for local residents. However I can't see that happening. You'd have to have the tanks of it very close to the reactor. That's something you'd obviously not do. There's probably a greater risk transporting the stuff (road accidents) or in bad maintenance of the tanks or human error (emptying the tanks by accident).
- amluto 7y agoIt seems to me that one could avoid storing any tritium as a liquid. Tritium gas is light will generally tend to rise. Insoluble tritium salts will be less likely to enter the ground water. Although... an inexpensive risk mitigation would be to wrap any tritiated water tanks with sodium polyacrylate. Imagine a giant diaper. Leaks would be absorbed.
- DennisP 7y agoIt wouldn't hurt you a bit if containment failed while you're in the building. The fusion plasma is held at very high temperature but there's very little of it. It's only ever at high pressure in inertial fusion, which doesn't actually contain the plasma at all except for a tiny fraction of a second before it explodes by design.
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- K0SM0S 7y agoBasically, none that we need to be concerned with. The general idea is this: when you fuse elements, you produce heavier elements; if you wanted to fuse these new elements into even heavier ones, you'd need to input much more energy — thus it can be said in layman terms that the products of fusion are 'toxic' to the fusion itself, i.e. the more you do it the less likely it is to go on, until if finally stops (like in real-world stars). For instance, the Helium produced by the Sun is making it harder to sustain the Hydrogen fusion, which will stop before all Hydrogen is depleted. In addition, the radioactive elements produced by fusion are much lesser than fusion, by orders of magnitude, so it's pretty much 'clean' in that regard for all intents and purposes (50 years of fission probably produced much worse than 1,000 years of fusion would). And the fuel is available in pretty much limitless quantity — in fact, it would probably make a space industry, starting with mining hydrogen isotopes for fusion, profitable from day 1. It's basically the closest thing we have to God's tech, and there's not much else in theoretical physics that comes close in terms of benefits in our real-world context. Fusion would essentially hand over the galaxy to us with little to no chance of failure, given enough time. If we can pull it off, that is. Which remains to be seen, there's nothing new or groundbreaking in this article.
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- vbezhenar 7y agoWorst thing is an (non-nuclear) explosion releasing some radioactive matter with small contamination. From my understanding it's similar to conventional power plant explosion and contamination is negligible (nothing like fukushima disaster). It's not possible to get uncontrolled fusion, at least for reactor designs we are considering now. It requires star scale to have uncontrolled fusion.
- buboard 7y agoFusion to higher molecular weight atoms releases energy until it turns to Iron. I don't think it is possible to have energies for fusion beyond helium however.
- Svoka 7y agoI would say "none" but just containment failing is not equivalent of meltdown. If left to own devices, fusion would stop. You can get some kind of explosion/fire, since you know, high energies are involved, but it would be simple thermal explosion. There are still issues, like most fusion reactions produce neutrons, which are not great by themselves, and basically most dangerous type of radiation. They can make regular matter radioactive. But we are far from that stage when this is a problem.
- Roritharr 7y agoTl;dr: The US tries smaller fusion reactors in partnership with industry in parallel to ITER. Nothing really new from a tech standpoint, or what am I missing?
- hamburglar 7y agoWell, I don't think you're wrong, but no need to be so cynical. :) This isn't like some industries where they might just pop up with a commercially viable product out of the blue and start making money. The nascent fusion industry needs support from the public in the form of public policy, research funding and investment. I wouldn't be surprised if this piece was basically fusion industry PR machine reminding us all that they still exist and could be interesting in the near future. My understanding is that so far, it doesn't look like wind/hydro/solar can scale to our needs within the timeframe that fusion might be viable (and yes, I know, it's "always 20 years away", but hopefully that changes eventually), so it's still a worthwhile pursuit, IMO.
- tanbog 7y agoI don't begrudge money being spent on researching fusion. It is definitely a promising technology, but it's not coming to a power grid near you any time soon. Even if we can figure out how to keep a reaction going with a useful energy surplus no one has any idea a) How much a reactor will cost, b) how long/hard will it be to build or c) If there are any issues with the process - yes no nuclear fuel but there's still some nasty crap coming out of the reaction which you will have to deal with if you scale the technology. Meanwhile there are a number of perfectly viable planet saving power sources - solar, wind, solar-thermal etc - already out there providing power. Fusion is a nice idea, but it isn't the only way to save the world...
- bbddg 7y agoAlso given the time frame that we need to decarbonize the grid, we can't really put our hopes in fusion for the near to medium term.
- pmoriarty 7y ago"it's not coming to a power grid near you any time soon" "soon" is relative. The older I get, the more something a century or even two away doesn't seem that far off, and something that could arrive in 20 years seems positively near. The Long Now project strives to get people to think more long-term, and I've heard that in some parts of Asia governments and organizations plan on far longer time horizons than is common in the West. The world would be far better off if more of us adopted such a perspective, rather than focusing on only on what can be done now or in the next few years.
- perfunctory 7y agoI totally agree with your sentiment in general. However, when you wake up in the middle of the night and realise your house is on fire, you don't have time to ponder the future fire prevention technologies. You need to get out of bed and start putting the fire out. "House on fire" is where we are now in regards to climate change.
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- chmaynard 7y agoActually, it's too late to save the planet. The best we can do is adapt to the new climate as it rapidly emerges. Let's devote what time we have left as a species to making the best possible use of the energy provided by that great fusion reactor in the sky, the Sun.
- millstone 7y agoClimate change is not going to lead to our extinction.
- com2kid 7y agoThe resulting socio-economic upheaval might. Millions of people starving or mass migrating due to changes in food supplies are bound to cause a bit (lot) of conflict. A few degrees change in temperature can dramatically alter weather patterns, the places that used to be good for growing crops may no longer be so. Sure we can adapt and move farms, but the years until that infrastructure gets rebuilt may not be pretty. It only takes 1 person with a red button to end it all.
- toss1 7y agoI would not be so sure about that. There are a variety of scenarios where climate change breaks the food web, e..g., ocean acidification (which is happening much faster & in greater amounts than anticipated). While not extincting all life, & some humans plausibly survive, it is normal for populations to collapse to 10% of previous under conditions losing only down to 80% of previous feed stock -- when down to <10% of feed stock, how many survive?
- baron_harkonnen 7y agoThe key to surviving climate change is having the energy resources to do so. Resource depletion is happening at roughly the same speed as climate change is impacting us. We do not live in a sustainable way. Nobody would seriously argue with that claim, but the implication is that our way of life is unsustainable. Extinction is a bit extreme but the way we live, our global civilization, is not one that can be sustained. We're showing absolutely zero signs of seriously slowing the pace of our resource consumption or waste production. Only time will tell what it looks like when we go from unsustainable to the consequences of that. But given that without hydrocarbons our biosphere can probably only support about 1 billion humans... we're in for a rough time.
- hanoz 7y agoBut is this just saving the planet from only the most pressing symptom of human over population? If we do get an abundance of cheap clean energy, what then?
- darawk 7y agoAn abundance of clean energy would solve a pretty huge amount of our problems for quite a while. That's not to say that everything would be great forever...but we'd have a whole lot more breathing room to figure things out.
- hanoz 7y agoMore breathing room for mankind, yes, but not necessary the rest of the natural world.
- darawk 7y agoI'm not really sure what you mean by that. Firstly, we are part of the natural world as much as anything else is. Secondly, having access to clean and abundant energy would allow us to do a lot of things to preserve the other parts of the natural world that we are currently not doing because it's too expensive.
- hanoz 7y agoI did say the rest of the natural world. If it turns out that the only way to bring down carbon emissions is to make low carbon energy much cheaper, then why would anyone think that we'd spend our newfound wealth on cleaning up our act in other matters? There are a multitude of cases of human over-expansion proving catastrophic for other natural environments which have nothing at all to do with climate change yet have been totally eclipsed by the issue. I don't know why anyone would think that much cheaper energy would help those cases rather than make them worse.
- darawk 7y ago
- jaytaylor 7y agoPaywall bypass: http://archive.is/b13zB http://archive.is/b13zB
- amilein7minutes 7y ago>> ''In contrast to its international competitors, the United States brings a worldview that favors early involvement of industry in technology development and a greater appetite for tackling technology risk if it leads to commercial viability.'' As an aside, fusion technology feels like a good testbed for what economic model is best for the democratization of a public good. Is government investment in the ITER countries a better accelerator than the American model of private companies being allowed to take advantage of research in govt institutions? I suppose we will know in a few decades when fusion contributes to the power grid.