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Nuclear-fusion reactor doubles record for energy made from fusing atoms

nature.com

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Re: Nuclear-fusion reactor doubles record for energy made from fusing atoms

#261

Post by orthecreedence »

ncmncm wrote: post #244
orthecreedence wrote: post #240

Earlier quoted context omitted.

Why not build both? Nuclear is great, and pound-for-pound is a much better energy source than solar, but you can build solar much more quickly than nuclear. I don't think your rebuttal is particularly damning. My points against solar I raised to you in another thread stand: to build the panels/batteries we need, it will create an extreme excess of carbon in the atmosphere. That's not to say we shouldn't build solar,…

I.e., never. " What a terrible bet solar and wind are ", as you claim immediately above, would be a reason not to build out solar and wind, if it were correct. But it's not, and they are. And, it is at best naive to believe that it takes more energy to produce a solar panel than it will generate. People mining and refining silicon, cadmium, and tellurium and making solar panels out of them do not get power for free.…

> as you claim immediately above

The claim was regarding nuclear VS solar (either/or), in which case yet, solar is a terrible bet. I stand by that.

> People mining and refining silicon, cadmium, and tellurium and making solar panels out of them do not get power for free

And you say I'm being naive...

Firstly, the price of the panels doesn't even match the price of production because of subsidies.

Secondly, they do get power for free: the well-known, terrible cost of burning fossil fuels at their current scale is not incorporated into the price of fossil fuels. Capitalist markets are not capable of doing so.

So my point is if you were to actually price fossil fuels according to their cost solar panel production would not be competitive with nuclear in any way.

> When your panel's production output pays off its purchase cost, its output has (much more than) exceeded the energy used to produce it.

Sure, it can pay off its purchase cost, but as above, that means absolutely nothing. A more interesting payment would be watts-in, watts-out, in which case I'd wager you get marginal gains. And if the watts-in are generated with fossil fuels, you're doing a lot more damage than you think.

Regarding nuclear, sure it's expensive, but a lot of that is artificial, and a lot of the high comparative cost is due to the price/cost disparity in fossil fuels. And hey, as a bonus, it works at night and on cloudy days and you don't need to build an enormous battery which is another can of worms people love to gloss over.

Re: Nuclear-fusion reactor doubles record for energy made from fusing atoms

#262

Post by ncmncm »

ncmncm wrote: post #234
nightgarden wrote: post #87

Earlier quoted context omitted.

Isn't fusion safer? If fusion was a viable option for countries that are phasing out fission like Germany then it could solve a lot of problems especially decreasing reliance on gas

Thousands of tons of radioactive molten lithium would be quite noticeable if spilled, especially since it would instantly burst into flame, and spraying water on that would make it explode. On the plus side, it wouldn't be very radioactive, not like a nuke meltdown. Mostly molten and on fire.

... and emitting deadly lithium oxide fumes:

"Acute inhalation toxicopathology of lithium combustion aerosols in rats", A.H.Rebar, B.J.Greenspan, M.D.Allen

"Male and female F344/Lov rats were exposed to aerosols produced by burning lithium metal under conditions designed to simulate a fire in the containment building of a fusion reactor. ... 14-day LC50 values ... were 940 mg/m^3 ... necrotizing laryngitis and ulcerative rhinitis"

[0] https://pubmed.ncbi.nlm.nih.gov/3089861/

[1] https://sci-hub.se/10.1016/0272-0590(86)90197-1

Re: Nuclear-fusion reactor doubles record for energy made from fusing atoms

#263

Post by ncmncm »

mrfusion wrote: post #149
panick21_ wrote: post #78

Fusion has no practice reason to exist compare to advanced fission. The improvements in energy density are not really relevant factor at that scale, meaning the difference from oil to fission, and oil to fusion doesn't really gain you much. Fusion fuel cost over the long term is likely more expensive then a fission fast breeder (not to mention a potential of thorium thermal breeder). Is a fusion reactor going to be c…

Even if true, fusion could definitely have a place in space travel where every kg matters.

But not hot-neutron fusion, which requires thousands of tons of molten lithium to absorb the neutrons.

In space, you want D-H3 fusion, or pB fusion if you can manage it.

Re: Nuclear-fusion reactor doubles record for energy made from fusing atoms

#264

Post by ncmncm »

bobsmooth wrote: post #19

As with every fusion article, I encourage anyone interested in the space to look into General Fusion. They're using liquid metal as both the reaction vessel and as a means to extract power. Really cool stuff.

This actually looks like it could be practical. Important differences from the Tokamak concept are:

1. No enormous magnets

2. No exposure of fragile equipment to hot neutrons

3. The reaction occurs in a bubble inside molten lead/lithium, compressed mechanically.

4. None of the pipes carrying hot metal (or anything else) are exposed to hot neutrons, so need not be replaced frequently.

5. The amount of molten metal is relatively small -- not thousands of tons, but just tons (much of it lead, why?)

Similarities are that the fusion energy is carried by kinetic neutrons absorbed in molten metal, and extracted by heat-exchange with another fluid, thence to steam; and the molten metal is processed continuously or periodically to extract tritium, which will serve as more fuel.

Big question is if the reaction rate is high enough. It seems to depend on how much plasma can be packed into the bubble before it is compressed, and how long you have to keep it compressed before releasing and exhausting the synthetic helium. It seems like if there is any tritium left over afterward, you would want to cool and reclaim that.

You get one hot neutron out per tritium in, which in a Li6/Li7 mixture might breed [0] two tritium out, plus some helium. With lead mixed in, wouldn't it steal slow neutrons you need to get above parity? I guess as long as the lead doesn't steal too many, it is OK? But what is the lead for?

[0] http://hyperphysics.phy-astr.gsu.edu/hbase/NucEne/fusion.htm...

Re: Nuclear-fusion reactor doubles record for energy made from fusing atoms

#265

Post by urthor »

stormbrew wrote: post #216
urthor wrote: post #22

Earlier quoted context omitted.

We're realistically at a very good point in time to avert some of the worst case scenarios, I fail to see your point? We definitely want to be looking at technologies that have a high ROI for emission reduction in the next 10 year span, mixed with longer term projects. Fission is a longer term project. Simple as that.

> We definitely want to be looking at technologies that have a high ROI for emission reduction in the next 10 year span, mixed with longer term projects. This... is my point? So I think you do see it. "Fusion can't save us now so we shouldn't invest in it at all" is short-sighted. This is not an either-or proposition, and frankly people have completely out of whack ideas of the scale of money that's been invested in…

See this is the thing.

People thing 10 billion dollars is a lot of money.

My view is that 10 billion dollars is nothing.

My view is that the total OECD investment in fusion R&D should be 10 billion. A year. For the next 50 years.

The investment in the high ROI technologies, principally solar R&D and overnight energy capacity projects like water pump batteries, should be 100 billion (across the OECD). And the investment in CapEx, installing new panels, 200 billion.

Our investment in STEM R&D, as a society, is just pitiful across the Western world.

The portion of our tax dollars that go to long term R&D, the primary driver of productivity growth and progress in our nation's, is scrap.

Re: Nuclear-fusion reactor doubles record for energy made from fusing atoms

#266

Post by ncmncm »

Aeolun wrote: post #122
ncmncm wrote: post #62

Earlier quoted context omitted.

The energy flux density in the most compressed plasma imaginable is orders of magnitude less than in fissile uranium. So, to match power out, it has to be big. Really, really big. And a fusion reaction chamber is a much more expensive affair than a fission pile: super high-tech materials and construction, enormous magnets (blasted by the hot-neutron flux output), piping for thousands of tons of melted lithium that ha…

I find it hard to believe that people would be seriously researching this if we already knew there could never be any sensible commercial application. More likely we just don’t know the way to make it viable yet.

In some hypothetically possible world, policy choices are based the best reasoning from the latest information. We, alas, live in this world, where policy is mainly a product of history. The H bomb legacy looms large here.

We are in the position of the person whose car keys were lost somewhere, but we are looking only under the D-T fusion streetlight because we can't see anywhere else.

Re: Nuclear-fusion reactor doubles record for energy made from fusing atoms

#267

Post by vlovich123 »

pfdietz wrote: post #252
vlovich123 wrote: post #142

Earlier quoted context omitted.

Fission did keep getting cheaper up until FUD about accidents and explosions caused regulations that strangled it (that and overblown fears about proliferation of nuclear weapons).

Yeah, like all those whiners complaining about how first generation BWR containment was totally inadequate. Never mind what happened at Fukushima, right? /s

The amount of accidents and their severity does not line up with the disproportion strangling the technology has experienced at the hands of regulators. If we go down that road, all coal plants should be shut down long ago as they’ve been responsible for more radiation-caused deaths than all nuclear deaths combined (including due to the bombs if I recall correctly). That’s not even counting the deaths they’ve caused through air pollution.

Heck, nuclear is still competitive with solar and wind in terms of deaths/MW produced. And this is all the more stark considering nuclear designs stagnated 60 years or so ago. If we hadn’t divested from that technological path we’d have drastically cheaper and safer nuclear energy today and global warming potentially wouldn’t even be a problem.

Re: Nuclear-fusion reactor doubles record for energy made from fusing atoms

#268

Post by pyinstallwoes »

eutectic wrote: post #58
pyinstallwoes wrote: post #45

Earlier quoted context omitted.

A 1000% return is insane economically. Perhaps I'm not seeing the logic but the pure YOY return on 1000% seems to logically conclude a rational strategy of "nothing else matters besides building this and it will easily pay off and investment"

Q is just energy out over energy in. It is not an economic return.

Yeah but what else puts out more than puts in energy wise?

Re: Nuclear-fusion reactor doubles record for energy made from fusing atoms

#269

Post by pyinstallwoes »

ncmncm wrote: post #56
pyinstallwoes wrote: post #45

Earlier quoted context omitted.

A 1000% return is insane economically. Perhaps I'm not seeing the logic but the pure YOY return on 1000% seems to logically conclude a rational strategy of "nothing else matters besides building this and it will easily pay off and investment"

A 1000% return only just covers unavoidable inefficiencies. No Tokamak will ever pay off its investment.

Right, that’s the ridiculousness of it.

Re: Nuclear-fusion reactor doubles record for energy made from fusing atoms

#270

Post by pyinstallwoes »

ahoka wrote: post #75
pyinstallwoes wrote: post #45

Earlier quoted context omitted.

A 1000% return is insane economically. Perhaps I'm not seeing the logic but the pure YOY return on 1000% seems to logically conclude a rational strategy of "nothing else matters besides building this and it will easily pay off and investment"

This just means for every n W of _heat_ injected the fusion creates 10n W of heat. But I'm pretty sure the experiment itself consumes much more electricity than it could theoretically produce (don't forget that converting heat to electricity has an efficiency below 50%). Fusion researchers mislead the public to get more funding when they say ITER will make more energy than it requires. Fusion might be never viable.

Yeah well anything above a ratio of 1 would be beyond anything we have in terms of return based on investment in relation to cost to generate heat and it’s output. Basically all technology thus far is <1 right?
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