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Experts Urge US To Continue Support For Nuclear Fusion Research (scientificamerican.com)
An anonymous reader quotes a report from Scientific American: A panel of 19 scientists drawn from the National Academies of Sciences, Engineering and Medicine recommended yesterday that the Department of Energy should continue an international experiment on nuclear fusion energy and then develop its own plan for a "compact power plant." A panel of 19 scientists drawn from the National Academies of Sciences, Engineering and Medicine recommended yesterday that the Department of Energy should continue an international experiment on nuclear fusion energy and then develop its own plan for a "compact power plant."
But as the National Academies' report noted, major challenges must be overcome to reach these goals, beginning with how to contain and control a burning "plasma" of extremely hot gas, ranging from 100 million to 200 million degrees Celsius, that can produce more heat than it consumes. The report calls the resulting plasma "a miniature sun confined inside a vessel." The world's biggest experiment intended to create and draw energy from burning plasma is under construction at Cadarache, France. It's called the International Thermonuclear Experimental Reactor (ITER) project, and its centerpiece is a large, doughnut-shaped, Russian-inspired reactor called a tokamak. Several member nations have already developed their own national programs, and the assembled National Academies experts concluded that the United States should eventually follow, once the ITER experiment shows there are ways to contain and manipulate a sustained fusion reaction. "It is the next critical step in the development of fusion energy," says the report.
But as the National Academies' report noted, major challenges must be overcome to reach these goals, beginning with how to contain and control a burning "plasma" of extremely hot gas, ranging from 100 million to 200 million degrees Celsius, that can produce more heat than it consumes. The report calls the resulting plasma "a miniature sun confined inside a vessel." The world's biggest experiment intended to create and draw energy from burning plasma is under construction at Cadarache, France. It's called the International Thermonuclear Experimental Reactor (ITER) project, and its centerpiece is a large, doughnut-shaped, Russian-inspired reactor called a tokamak. Several member nations have already developed their own national programs, and the assembled National Academies experts concluded that the United States should eventually follow, once the ITER experiment shows there are ways to contain and manipulate a sustained fusion reaction. "It is the next critical step in the development of fusion energy," says the report.
Ahh, this old canard.
Here, this handy little chart should help you understand what is actually meant with that.
There are some pretty well established scalings that have been determined, basically saying if you have a given magnetic field, tokomak radius and shape, you will get a specific Q. The basics of containing plasma in a tokamak have been worked out some decades ago, and some of the final details have been worked out in the last 20 years, like disruption prevention and mitigation schemes.
We know a fusion reactor will work if built big enough (and I'm not talking about the joke about making it the size of the sun). The question is what is the least amount of increase in size we can get away with, because costs scales very roughly with volume of the reactor. How much stronger magnets can we develop and how much heat flux can the first wall takes (gets worse for smaller machines)?
This is getting into the realm of engineering, where the question is not, "Is it possible?," but instead, "Is it possible on a economical budget?"
Fission reactors can't suffer nuclear detonation either (that's right, the climax of Pacific Rim wouldn't work in real life). You need specific isotopes of uranium or plutonium to make a bomb; isotopes which actually impede the functionality of the reactor as an energy source.
Chernobyl suffered a thermal explosion. So much energy built up so quickly the reactor fuel vaporized and blew apart the building. It was not a nuclear explosion. And it should be noted that Western nuclear reactors cannot blow up as Chernobyl did because they're designed with a negative void coefficient. They're designed so if the cooling water starts to boil, it slows down the nuclear reaction. Chernobyl's design used a positive void coefficient - boiling water sped up the nuclear reaction. The moment its coolant started to boil, the reactor was doomed. Positive void coefficient reactor designs were never used in the West because of this inherent instability. The Soviets were more interested in building something cheap, rather than safe.
Even the right isotope of uranium or plutonium, building a bomb is very hard to do. The materials will not blow up in a nuclear explosion by themselves.. There were two supercriticality accidents with a plutonium core during the Manhattan Project. The two halves were accidentally put together close enough where the nuclear reaction became self-sustaining. All that happened was it gave off a bunch of radiation killing the nearest scientist. It did not blow up.
To make it blow up in a nuclear explosion, you have to crush the uranium or plutonium far beyond its normal state. The atom bomb dropped on Hiroshima used a gun. A uranium bullet was fired at another uranium mass, briefly increasing the density beyond that needed for the supercriticality to cause a nuclear explosion. The atom bomb dropped on Nagasaki used explosives to implode a shell of plutonium (this is the method used in modern nuclear weapons). When the shell pieces collided in the center, their density briefly exceeded what was needed for a nuclear explosion. if they don't all meet in the center at the exact same time, then either there's no nuclear explosion, or you get a small nuclear explosion (this is why the yields in North Korea's nuclear tests were so small as to almost not register on monitoring equipment)..Getting all those explosives to go off at the exact same time with the right force in the right direction is really, really hard.
Incidentally, fusion is so much harder to achieve that a fission nuclear bomb is used to create the pressures and temperatures needed to get hydrogen to begin to fuse, causing a fusion explosion. That's where the term "thermonuclear" comes from.
>"Why would we want the Americans to have it? They'll just find a way to use it for making war on brown people countries, like they always do."
Not only is that totally inaccurate, you fail to realize that one of the most major points of conflict in the world revolves around energy. If you would stop viewing the world through distorted, far-left lenses, you might discover that plentiful, safe, cheap energy would allow all countries a measure of peace, security, and prosperity like nothing else ever could.
>"Europe can't make war on other countries"
You desperately need to study actual history.
Know how long they have been trying?
We haven't been trying. The funding for nuclear fusion has been absolutely laughable. In all of 2018 the united states has spent less on fusion than Total has spent on their garden variety supercomputer to help speed up the processing of depth sounding for searching for oil.
They have spent less money on fusion research in 2018 than a single highway lane expansion project that we have running locally to add a single lane each way for a 10km stretch of road.
We're not trying. We're not even really giving the illusion of trying.
Hopefully the Europeans can get it to work, but they're already spending the money, so why does the US have to?
Because there's more than one aspect of fusion research, there are multiple proposed ways of achieving it, and letting someone else do something in the off chance that they get it working first go is making a losing bet, if they lose we're no better off, if they win, we'll spend a lot of money paying them for their knowledge.