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Could a Helium-Resistant Material Usher In an Age of Nuclear Fusion? (sciencealert.com)
Researchers working with a team at the Los Alamos National Lab tested a new way to build material for nuclear fusion reactors, "and found that it could eliminate one of the obstacles preventing humanity from harnessing the power of fusion energy." schwit1 quotes Science Alert:
A collaboration of engineers and researchers has found a way to prevent helium, a byproduct of the fusion reaction, from weakening nuclear fusion reactors. The secret is in building the reactors using nanocomposite solids that create channels through which the helium can escape... Not only does the fusion process expose reactors to extreme pressure and temperatures, helium -- the byproduct of fusion between hydrogen atoms -- adds to the strain placed on reactors by bubbling out into the materials and eventually weakening them...
In a study published in the journal Science Advances, the researchers overview how they tested the behavior of helium in nanocomposite solids, materials made from thick metal layer stacks. They found that the helium didn't form bubbles in these nanocomposite solids like it did in traditionally used materials. Instead, it formed long, vein-like tunnels. "We were blown away by what we saw," said Demkowicz. "As you put more and more helium inside these nanocomposites, rather than destroying the material, the veins actually start to interconnect, resulting in kind of a vascular system."
The article points out that nuclear fusion generates four times the energy of nuclear fission.
In a study published in the journal Science Advances, the researchers overview how they tested the behavior of helium in nanocomposite solids, materials made from thick metal layer stacks. They found that the helium didn't form bubbles in these nanocomposite solids like it did in traditionally used materials. Instead, it formed long, vein-like tunnels. "We were blown away by what we saw," said Demkowicz. "As you put more and more helium inside these nanocomposites, rather than destroying the material, the veins actually start to interconnect, resulting in kind of a vascular system."
The article points out that nuclear fusion generates four times the energy of nuclear fission.
I’m been hearing fusion is only 20 years away for at least 30 years now.
It is worse than that. The time until we get fusion power is a monotonically increasing function of calendar year. In the early 1950s, when Project Sherwood was started, it was highly classified because it was thought that it would produce fusion power so soon (i.e. less than a decade) that it would be a valuable military technology. By the late 1960s they were talking about it being achieved in 20 years. By 2000 the timeline had grown to 30+ years.
In 2014 the projection for DEMO, the ITER follow-on, which is described as a system that would bring us to the "threshold of a prototype fusion reactor", i.e. short of being an actual prototype fusion power reactor, which in turn is short of being an actual commercial power reactor, was projected to start operating in the 2040s, i.e. at least 30 years, if no further schedule slippages occur. Currently, PROTO, the actual prototype fusion power reactor is not envisioned before the 2050s and likely later, which brings us about 40 years, and we still aren't talking about an actual commercial power plant. Allowing for the established 20 year cycle for each iteration of a major fusion reactor project, we might get that commercial power plant in 60 years. But it will be too expensive to compete with other sources of power.
Is some other new fusion design going suddenly break us out of this pattern? There is no law of nature against it, so it is possible. But literally hundreds of fusion schemes have been investigated, and without exception every concept has proven much harder in practice than on paper (or computer). Engineering by press release does not cut it (Lockheed Martin I am looking at you), until an actual demonstration unit is operating with predicted performance all claims on new breakthroughs should be ignored.
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
> and insurmountably too expensive due to physics
It already has, and everyone knows it. It's not just fusion, it's fission too. If you have neutrons in the first loop, you are uneconomical. Period.
The cost of a modern fission reactor is around $10/Wp. Of that, about $6/Wp is the generation loop. Only about $1 to $1.50 is the actual reactor itself.
So in other words, the lowest possible price you can build a [fission|fusion] plant for is about $6/Wp. And that's without the reactor.
A wind turbine that produces the same amount of power costs about $1.25/Wp. Because the wind doesn't always blow, to make the same amount of energy you need three of them. So a generator using wind turbines that produce NNN power will cost you about $4.50 complete, whereas for $6 you still only have a cooling loop on your nuclear plant.
The power companies have been telling the labs they won't build these things since the beginning. The Stellarator D study in 1958 produced a machine that was 500 feet across and twisted like a pretzel. The power company liaisons working on the report told them there was absolutely no way anyone would ever build such a thing. The physicists basically said "who cares" and went back to their physics, saying that since the physics didn't work then the study was dumb anyway.
That pattern repeated itself dozens of times over the next 30 years. Every so often someone would think they were getting close to a working design, and they would do a commercial design effort. And every time, the power companies would tell them in no uncertain terms they were smoking pure hopium. GE threw in the towel in 1965 when they did their own study that said the same thing. The largest one I know of is the Bechel report from ~1975, and once again the same outcome - no way anyone would ever build one.
Everyone in the field is aware of this. It's gotten to the point that if you bring this up they either yell at you (literally, had this happen to me) or do the equivalent of "LA LA LA I CANNOT HEAR YOU!". It's astonishing to watch.
Is some other new fusion design going suddenly break us out of this pattern?
I think so. These magnetic confinement designs have a toroid shape to the plasma, making the volume of plasma needed for breakeven much larger than if it was a sphere. Spherical containment using a magnetic field is not likely possible. What would be possible for spherical containment is an electrostatic force. There's been some research in this funded by the US Navy but they've always been very secretive and underfunded because the Navy suspects that if the project got too large then it'd be taken over by the Department of Energy and killed, as it competes with their magnetic confinement projects.
Another interesting confinement is to use a magnetic field but on a molten metal, the fusion fuel is contained in this molten metal "bottle". By using powerful rams to move the metal inward the fuel is compressed inside this collapsing bottle. The heat and pressure would, theoretically at least, fuse portions of the fuel and keep the metal hot. Repeated ramming would keep fusing the fuel and the excess heat is extracted to produce power.
These are far less expensive experiments in fusion compared to the tokamak designs that so many people (or nations rather, I don't think the people have much say on this) are dumping money into. I believe these other designs are also far more likely to be energy positive at a reasonable scale. Any fusion project can be energy positive if scaled large enough, we have ample evidence of that in the universe. The reason the US Navy is funding their own fusion project is that they believe it can be used to power a future aircraft carrier or submarine. I suspect that they will not find that feasible, but even then they must see value in this as a source of energy for military strategic reasons.
I recall reading some articles on these alternative fusion reactor designs and it was something like the power input required grew on the square of the diameter but the power output grew by the cube. Their early experiments required X watts of power in, gave Y watts of power out for a given diameter Z. For X to be larger than Y meant Z had to be, again as I recall, much larger than the size of a typical fission reactor. For this to be practical means the capital expense would be much larger than any fission project attempted so far. Who is going to spend that kind of money when fission is already a proven technology?
One thing that determines the size of the reactor is the fuel. Some fuels are better than others and, of course, the best fuels are rare and expensive. If we are going to use a lower quality fuel then the size increases even more.
What's going to break us out of this pattern of fusion always being 30 years in the future is the Department of Energy getting off the idea that magnetic fusion is the only path to take. They need to get serious on this and invest in, or at least issue licenses for, competing fusion technologies. If these competing technologies actually prove successful though then the Department of Energy would look really stupid for investing so much money into something that didn't work AND they'd actually solve the problem that they were set to solve, therefore making the future existence of the department unnecessary.
The Department of Energy isn't going to solve our energy problems because it would not be in their best interests to do so. So long as energy scarcity is a problem they have a mission. I say dissolve the Department of Energy and roll over much of its people, assets, and mission into the Department of Defense. What does not fit into the likes of energy development, nuclear weapons, research, and such, can be rolled into the Department of Commerce or some other government entity. The Department of Energy needs to go away. If we can't make it go away then we should put people in charge that are actually motivated to have the department pursue it's mission.
I am armed because I am free. I am free because I am armed.
Before you start worrying about the walls of your fusion machine, you need a fusion machine that can provide net positive energy.
Excuse me, but the point of this article is that the walls are part of the fusion machine.
When all you have is a hammer, every problem starts to look like a thumb.
Oh god not this chart again. Anyone that posts this is demonstrating that they are unfamiliar with the history and physics of fusion. So let's explore this...
Right when the entire concept was starting in the 1940s, there was a theoretical calculation that estimated how quickly the plasma would leak out of the machines. Among the various inputs were two that were key - the plasma leaked slower out of larger machines because it had further to go, so that was linear with size, and in addition, the scattering varied with the square of the magnetic field strength so if you made the magnets even a little stronger then you're good to go.
However, there was one problem. During the war, they had actually worked with magnetically confined plasmas as part of the bomb project. The actual measured results from these experiments were WAY faster than what the classical math predicted. Most worryingly, the magnetic field only improved the times linearly. If this "Bohm diffusion" was correct, there was no hope of making a working reactor.
So when they built the first machines and ran the calculations, it appeared the classical numbers were working. If they just made it bigger they would be off to the races. So through the late 1950s and into the 60s they did that. And sure enough, the results got worse. At a 1968 meeting, Spitzer, the dean of the US program, had a chart showing that the entire stellarator series was clearly following the Bohm model.
Fusion was dead.
Funny thing though... at that same meeting the Soviets showed the results of their new tokamaks and they were 10x Bohm. The results were so good, no one believed them. They had to invite a team from the UK to use their laser scattering probe before anyone was convinced it actually worked.
And then there was a sudden rush to build tokamaks. So much of a rush that they converted the biggest stellarator into one and never looked back. Now the problem was not stability, it was heating the fuel - previous machines like the pinch series heated the fuel by either compressing it rapidly or running a current through it. The tokamak showed that there were hard limits on both, and these were too low to use for heating.
So through the 1970s you had a series of experiments all around the world on how to heat the fuel. Generally, the US was the winner. The PPPL's PLT machine was able to hold its plasma and heat it until it reached the conditions for fusion. All that was left was to increase the pressure to a useful figure, and then introduce tritium so the thing would actually burn.
And that's where this graph comes in. Notice the start point of this graph, in the mid-1970s. This is when Hirsch was putting together the Manhattan Project-level attempt to make a working commercial machine around 2000. Based on this there were going to be three machines in a rapid sequence, first the follow-on to the PLT, which became TFTR, then a prototype generator that also handled tritium production, and then the prototype commercial machine. That's the green line in the chart.
What actually happened is that they built TFTR and it didn't work. As they ramped up the dials, the machine became increasingly unstable. By around 1983 TFTR failed, MFTF never even turned on, and congress, realizing no one really knew what the hell was going on, cut the funding.
So basically the green line is based on the underlying premise that they actually understood the physics. But they didn't. And if you don't understand the physics, it doesn't matter how much money you pour into it, it still won't work. So the black line happened.
In spite of this, fusion proponents keep putting this up and blaming money for "the problem". THIS IS A PHYSICS PROBLEM, IT'S NOT A MONEY PROBLEM. And we still don't really know the solution, and a trillion dollars won't fix that.
Good summary. Nuclear power is simply uneconomical compared with the newest, and rapidly developing, renewable technologies. There is a reason that world nuclear power production (not just in the US) has been nearly level for about 30 years. The era of nuclear power plant construction has passed, and super-expensive fusion ain't bringing it back when (and if) it becomes available.
A 21st Century electrical grid looks like this: high voltage DC power lines that ship electricity across an entire continent (800 KV lines can transport electricity from one U.S. coast to the other with losses under 5%), solar and wind power deployed in excess capacity (but still cheaper than the nuclear "base load"), pumped water storage to provide additional power leveling which, again, serves the entire continent. No need for expensive batteries, but you can build them too, and the technology continues to improve there as well.
The larger the grid the better because local conditions will average out, and you can take advantage of peak solar production in one place when evening demand peaks elsewhere, and so forth.
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj