The fusion energy dream is inching toward planet-saving reality

https://www.washingtonpost.com/opinions/2019/11/08/fusion-energy-dream-is-inching-toward-planet-saving-reality/

49 75 7 years ago

umvi• 7 years ago

What'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• 7 years ago

The 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• 7 years ago

There isn't enough fuel in the reactor to create something even close to a meltdown.

DennisP6• 7 years ago

It's hard to get fusion to happen at all. If something goes wrong, it just means fusion stops happening.

petschge• 7 years ago

The 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.

radicalbyte2• 7 years ago

Once 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• 7 years ago

Half life of Tritum is about 12.5 years, much more favorable than elements used in fission reactions.

DennisP6• 7 years ago

It 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.

K0SM0S• 7 years ago

Basically, 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.

vbezhenar2• 7 years ago

Worst 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.

harry8• 7 years ago

H-Bombs are not star scale. Seems uncontrolled to me...

buboard• 7 years ago

Fusion 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• 7 years ago

I 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• 7 years ago

Tl;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• 7 years ago

Well, 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.

tanbog5• 7 years ago

I 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• 7 years ago

Also 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.

pmoriarty3• 7 years 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• 7 years ago

I 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.

vanniv6• 7 years ago

This is the best argument for extensive research into life-span extension.

One of the megatrends of the last 200 years has been a huge increase in the time horizon deemed acceptable for investment payoff.

Generally, humans aren't willing to forgo things today for a payoff more than about half a life-span away. Today, a true long-term investor considers the 30-year return on their investment.

An investment that won't make a return for 50 years or more mostly isn't worth making.

But, if you knew you would still be healthy enough to enjoy the profits in 90 or 100 years, you might be willing to invest for the even-longer term (historical trends suggest this to be true)

Government grants are fun and all, but the way you get thing going big is to get them funded by people who are hoping to profit, not just hoping to make the world better in some way

Lev1a3• 7 years ago

nobody knows x about fusion

That's why research is needed otherwise researching will take the research duration plus the delay imposed by people saying it won't be here anytime soon anyway.

perfectly viable power sources like solar, wind, solar-thermal etc.

Until humanity has figured viable massively scalable long term power storage solutions we will always be at the mercy of natural phenomena (time of day, wind speed and direction etc). Additionally AFAIK "renewable power sources" don't have the necessary power density to make them viable as humanity's exclusive power source.

tanbog5• 7 years ago

Until humanity has figured viable massively scalable long term power storage solutions we will always be at the mercy of natural phenomena (time of day, wind speed and direction etc).

I would argue we just need to make sure ongoing power needs are met - ie we can always turn the lights on. This doesn't need "scalable long term" storage - although pumped hydro, batteries, thermal salt all work well - it just needs sensible grid design so the needs at any one time are met by available power sources.

This above is obviously a "harder" problem than to just have a few big power plants you can throttle on or off but not that much harder and we already have the technology and knowledge - if not the political will - to do it.

Additionally AFAIK "renewable power sources" don't have the necessary power density to make them viable as humanity's exclusive power source.

This is flat out wrong. many communities already exist exclusively on renewables.

darkmighty• 7 years ago

I too like the idea of Fusion reactors, (I am enamored with the dreamy prospect of fusion for space travel), but I think Elon Musk's observation is obligatory here:

Why spend huge sums in a fusion reactor, when we have a perfectly reliable funsion reactor right above us, the Sun, giving power at a convenient form (~500nm light -- far better than heat), at convenient power densities (not too high to overheat panels and not too low to be uneconomical), is available virtually everywhere, etc. It really is like we had already built a reactor and only need to add the last, least expensive, bit of energy harvesting.

The only thing Solar cannot compete well with are fossil fuels, which are essentially like discovering charged batteries buried in the ground (which is great, but they'll run out, and are ruining our environment), or wind/hydro in some places (where energy is begging to be harvested in the form of kinetic energy or potential).

Our salvation (for this crisis :) ) is indeed already within our reach, we only need to act...

mirimir• 7 years ago

Yep, our global fusion plant in the sky.

Nasrudith3• 7 years ago

The why is essentially density and availability. While solar is great for cheapness it has other constraints. It may still be more expensive in kWHr cost but it would certainly have its uses.

DennisP6• 7 years ago

The only thing Solar cannot compete well with are fossil fuels

So, that's sort of the point of fusion. It's clean energy with no need for storage.

pmoriarty3• 7 years ago

One way of harvesting solar energy that's technically possible but is not even on the horizon, as far as I know, is using giant mirrors or lenses out in space to focus sunlight down to Earth.

If it weren't for its potential use as a weapon, I'd look forward to seeing it put in practice.

ThomPete• 7 years ago

Solar and wind covers 1% of worlds energy consumption it's expected to be around 3-4% in 2040.

https://www.iea.org/weo/?fbclid=IwAR2LwDYcozvpGCOa3bIi2ieMbj...

trebligdivad• 7 years ago

'but it's not coming to a power grid near you any time soon' - there's about 5 companies aiming for ~2030 commercial fusion; so not terribly long - ok, most of them wont get there, but maybe if one does even a few years late? I think at least some of them have (a) & (b) in mind - (c) is probably harder.

lugg• 7 years ago

This comment could be posted on every article about fusion until there is a new fusion power plant opening day announcement.

Do you think it's worthwhile to discourage humanity from attempting new things because there are existing sub optimal alternatives?

Or are you just trying to sound contrarian for internet points?

(Despite what you're saying being the safest, most boring, done to death, remarks on fusion)

rladd• 7 years ago

You left out d) how long will it last?

Fusion reactions produce lots of neutrons, and neutrons weaken metal, in many cases within a few hours.

It may be that a "successful" fusion reactor is still a failure because it can run for only a few hours, days, or weeks before it has to be scrapped and completely rebuilt.

DennisP6• 7 years ago

I watched a presentation by the article's author, about MIT's ARC reactor design. He said they would replace the inner wall of the reactor once per year. In operation that would be surrounded by molten FLiBe salt, which would absorb the neutrons and breed tritium fuel. The inner wall would be 3D-printed, and the superconducting coils would be hinged so the reactor could easily open up; MIT has already tested joints in modern superconducting tape.

MIT spun off the company Commonwealth to commercialize the idea.

thiht• 7 years ago

Meanwhile there are a number of perfectly viable planet saving power sources - solar, wind, solar-thermal etc

And nuclear fission first, if you want to be realistic.

hanoz4• 7 years ago

But 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?

darawk3• 7 years ago

An 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.

hanoz4• 7 years ago

More breathing room for mankind, yes, but not necessary the rest of the natural world.

mepian• 7 years ago

The birth rates seem to be declining in the developed countries, to the point where we might have to worry about underpopulation rather than overpopulation as the markets stop growing and the older part of the population begins to strain welfare systems.

Lev1a3• 7 years ago

Problem is that population growth in developing nations is continuing to be explosive which isn't helped by developed nations "providing aid" which interferes with the natural limitations on population growth (i.e. food ressources within reach are insufficient => population can't reliably grow).

ClumsyPilot• 7 years ago

A lot of people talking about human overpopulation as it will grow infinitely.

Many dont realise that it's projected to max out at 10bn and then we will have a perpetual declining population / demographic crises.

tanbog5• 7 years ago

Neo-Malthusians generally only get as far as intro biology and avoid demography classes.

vanniv6• 7 years ago

Malthus has been dead for a really long time.

Nasrudith3• 7 years ago

Then it wouldn't be overpopulation anymore. Actual overpopulation is based upon carrying capacity exceeding the environment.

jaytaylor• 7 years ago

Paywall bypass: http://archive.is/b13zB

amilein7minutes• 7 years 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.

The fusion energy dream is inching toward planet-saving reality

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