Fusion energy is the darling of many people who are concerned about climate change.
As a trained physicist, actually a partially trained (4 year) nuclear physicist, I was never a believer in nuclear fusion as a potential power source even before it was being touted and vastly financed as a climate changer.
I knew how easy it was to produce nuclear power splitting heavy atoms, how utterly safe it was when intelligently installed, and how incredibly hard it was to cause fusion between hydrogen atoms despite being safer overall.
Fusion Energy not Instead of but With Nuclear Fission
The current nuclear reactors (like the ones which provide almost all electricity in France) use uranium (dug up) or plutonium (created in nuclear reactors) both of which can begin reacting at room temperature and pressure. The machinery to contain, control, and use nuclear reactions is also relatively simple, using some exotic metals to avoid damage from radiation, but essentially just a steam-powered power plant, with extra cooling, and a way to shove control rods back in place.
Fusion Energy, The Tritium Problem (Not for the Last Time)
I also knew, that despite how easy it was to find uranium, it was and is incredibly difficult to get tritium, the isotope of hydrogen that would work in most proposed fusion reactors. Tritium is simply the rarest of three hydrogen (one proton element) isotopes. As the name suggests, it has three neutrons – all hydrogen by definition have one proton and one electron.
Most fusion reactions, the easiest of an incredibly difficult process, use tritium.
Now other people in the physics field are beginning to speak out about the difficulties.
Fusion Energy, Other Skeptics
AUGUST 2024 Physics World particle and nuclear physics newsletter,
“The ITER nuclear fusion reactor has been beset by delays and cost overruns ever since its inception in the 1980s. But even by these standards, the latest setback is a major blow, with project officials announcing an additional 10-year wait before “first plasma” and an extra €5bn in costs.”
(In human actual money terms that is probably going to end up being closer to €7bn, these things always run over budget.)
Fusion Energy, More Tritium Problems
Since the ITER reactor uses Tritium, fully loading it to produce more power than it takes to run it (which has never occurred) could easily use all the world’s current stock of Tritium.
Besides getting the reaction to work usefully, just producing enough tritium to run one reactor is a major industrial task.
Fusion Energy, Where does Tritium Come From?
First, tritium is radioactive with a half life of about 12 years. That means if you have one gram of tritium (value $30,000) today and want to store it for future use, you will only have a half gram in 12 years and a quarter gram in 24 years (numbers approximate).
Inflation might mean your remaining half gram is still worth $30k but it is still only half as much and now is not pure.
Second, you get tritium two ways.
Tritium is generated in the atmosphere by cosmic rays. (Good luck collecting those atoms!)
The other way to create Tritium is in a nuclear reactor, the exact machines which fusion power is supposed to eliminate.
Fusion Energy Could Well Require Nuclear Fission Plants
So to get an initial load up of tritium you really need a nuclear reactor, which can generate electricity easily, to make the fuel for a fusion reactor.
You create tritium by bombarding lithium-6 or boron isotopes with neutrons from or in a nuclear reactor.
Of course, you can use plain old one proton hydrogen which is incredibly common, enough in a gallon of tap water to run a fusion reactor for a long time.
One slight problem with that however, it takes about 23,000,000,000,000,000,000,000,000,000,000,000 times more power to force simple hydrogen to fuse than to get tritium to fuse.
Fusion Energy – The U.S. Version
It’s not all bad news on the fusion front, though. The US DIII-D National Fusion Facility is now back up and running after a series of upgrades, and plasma physicists in the US have called for the construction of a new facility based on a stellarator rather than a tokamak-like ITER.
Meanwhile, small firms like the US-based Zap Energy continue to explore alternative fusion strategies.
https://science.osti.gov/fes/Facilities/User-Facilities/DIII-D
Experiments are soon set to resume following eight months of upgrades at the DIII-D National Fusion Facility.
DIII-D is a stellarator toroid which is essentially a donut-shaped containment vessel rather than the ITER tokamak. The tokamak is of early Russian design.
The stellarator contains atoms in a powerful, REALLY powerful magnetic field requiring supercooled magnets, turning them into a plasma (atoms stripped of all electrons) generating temperatures similar to those inside stars which naturally cause fusion. The temperature increase is due to fluctuating magnetic and electric fields which put energy into the plasma.
ITER also confines plasma but mostly adds energy with high-powered LASERS.
(Both greatly simplified.)
The DIII-D National Fusion Facility’s stellarator has a major radius of 1.67 meters and a minor radius of 0.67 meters. It uses has a toroidal magnetic field of up to 2.2 teslas or 50,000 times the earth’s magnetic field, a heating power of up to 23 megawatts, and a plasma current of up to 2.0 megaamps.
Those, except for the 2.2 Teslas are big numbers.
But that is just the tiniest part of the the entire facility and the machinery required just for the experimental structure, let alone the additional equipment to make use of any surplus power it generates to create useful electricity to feed into the power grid that runs the AC in your house.
These are far more complex and expensive than the controls and extra machinery needed in a fission nuclear power plant we use today.
One big problem is finding materials that can last for more than a few years when constantly bombarded with neutrons from the fusion reaction.
Another is that we can not produce the pressure in the center of the sun where fusion occurs naturally. On earth we need to generate plasma at 100 million degrees Celsius, or about six times hotter than the interior of the sun.
(Remember the sun? It can blind you and even strike you dead at 93 million miles distance.)
Bulletin of the Atomic Scientists, April 19, 2017.
(Disclaimer, I am a strong supporter of The Bulletin, the Doomsday Clock People.)
Fusion Energy Bottom line
Given the incredible amount of physics and engineering still to be done combined with the massive size of a fusion reactor, the difficulty obtaining fuel, and the risk of any new and untried leap into the engineering future, what are the chances of seeing fusion power?
Add to that the fact that, just as they did when nuclear power was being introduced, oil and gas companies, the ones spreading conspiracy theories and lies about climate change today, will spread rumors and false, scary information to trick the public into fearing fusion energy too.
(In 1963 I toured the first commercial nuclear power plant near Pittsburgh, it functioned for decades with no accident leaving a small open park in its original place today.)
No, fusion power to change our lives for the better is little more than a pipe dream and the pipe isn’t even filled with tobacco but something more hallucinatory.
