From the Energy Matters archives: Robert Hirsch provides a unique perspective on the economics of fusion power. Hirsch has previously been a Director of fusion research in the US Atomic Energy Commission. Imagining Fusion Power.
From the Energy Matters archives: Robert Hirsch provides a unique perspective on the economics of fusion power. Hirsch has previously been a Director of fusion research in the US Atomic Energy Commission. Imagining Fusion Power.
Even if commercially viable fusion is 5 major breakthroughs and 100 years away, its still worth pursuing.
D-D fusion instead of D-T fusion should be the focus, though.
Tokamaks are an expensive way to achieve controlled nuclear fusion. Inertial electrostatic confinement is a far cheaper and simpler method.
As the article states, one of the drawbacks of using D or T reactions is the production of neutrons. Eventually, the lining of the tokamak vessel will have to be replaced because the material will fail due to the absorption of all of those particles.
One group looking at IEC has suggested using proton-boron reactions. Yes, it produces less heat than those using hydrogen, but no neutrons are produced and, aside from heat, the only product is helium.
Protons can be readily produced as they’re simply ionized hydrogen atoms. Boron is available as borax and that’s easily mined.
So what are we waiting for? The concept has been demonstrated through work done by the late Dr. Robert Bussard and the group he led. Their major problem, as is the case for many researchers, was lack of funding to continue.
Fascinating!
Sadly, it needs higher temperatures to achieve fusion, a but of a block, but definitly still worth pursuing.
Myself, I’ve always thought muon-catalyzed cold fusion is cool, despite the alpha-sticking problem. I guess I think that the potential commercial use of exotic matter like muons is fascinating, a sort of a threshold in our technological development.
I, for one have never understood the wannabe love affair people have had with D/T fusion. Lots of neutrons, lots of induced radioactivity, and really, really difficult maintenance shutdown/turnaround cycles to replace components that have been degraded and made very radioactive by all those neutrons.
It will never be cheap, and never be “clean” no matter how well it can be controlled.
Correct. Tritium is much, much more expensive than gold. Who wants a gnerator that works by burning gold?
D-D fusion is the way to go.
I recall being told … back in the 1970’s during the OPEC-induced “energy crisis” that Nuclear Fusion was the future of mankinds every energy need. All we needed was more “investment” in clean, waste-free, Nuclear Fusion … and about 30 years … and we would all be flying our cars with “Mr. Fusion” on-board reactors.
Then, the anti-nuke hippie-greenies got old … got political power … and reverted back to the same solar panels and windmills that “would have” worked in the 1970’s … if they were just implemented correctly (read: MORE taxpayer subsidies). The same way that Socialism just hasn’t ever been “implemented correctly”.
Sadly, it needs higher temperatures to achieve fusion, a but of a block, but definitly still worth pursuing.
One major difference between tokamaks and focused fusion devices is that the former is based on probabilistic collisions. In other words, the high temperatures are required to provide the random motion required by the atoms enough motion and energy so that they can come in close proximity with each other. Such close encounters don’t necessarily result in collisions which will result in fusion.
By comparison, in focused fusion systems, the actual fusion occurs in the centre of a spherical volume. In simpler machines, the reactants are brought together by applying a voltage difference between an outer shell and a grid in the centre where the reaction occurs. The entire reaction system is contained inside a set of magnetic fields. High temperatures such as those required by tokamaks are unnecessary.
I, for one have never understood the wannabe love affair people have had with D/T fusion.
I’m not sure why the heavier hydrogen isotopes are favoured for fusion reactions. I’m reading a book on nuclear fusion and it may give a reason.
It’s easy to see, though, why hydrogen is used as a fuel. It’s the most common element in the universe (along with stupidity, but that’s another story) and can be easily obtained through, say, the electrolysis of water.
A small fraction of that hydrogen will be deuterium and an even smaller portion will be tritium. What makes those expensive is that they have to be separated from the hydrogen.
I remember the perpetual “in another 20 years” line that was often trotted out every time a new milestone in controlled fusion was achieved. It’s been that way since at least the late 1970s and probably started even earlier than that.
As far as the “anti-nuke hippie-greenies” you referred to, look up who Amory Lovins is. He’s about as bad as David Suzuki, though, at least, he does have a background in renewable energy.
Tritium is radioactive, with a half-life of about 15 years. It has to be manufactured.
Only stars can pull off regular hydrogen fusion. We can’t even do that in nukes, and stars need to use carbon 12 to catalyze the reaction.
Deuterium is pretty cheap, something like 0.1% of hydrogen on Earth is deuterium, basically enough to feed us energy for a million years, if we can figure out how to fuse it in a controlled fashion.
Another reason why hydrogen and its isotopes are used for fusion reactions is the heat that’s produced.
By comparison, the proton-boron reaction has a significantly lower thermal yield.