Fusion energy, as a practical method of generating electricity, is one of those things that's always promised to be just a few years away - over, and over, and over. There have been some breakthroughs, as we've covered right here in these virtual pages, but so far, no practical grid-scale fusion power. Yet. Fission power is another story, and the advent of Small Modular Reactors (SMRs) is making fission power more and more practical and versatile all the time.
Is that changing now? In a column at, interestingly enough, Oilprice.com, authors Leonard Hyman & William Tilles think that practical fusion reactors may beat SMRs to market, coming online as early as the 2030s.
Color me skeptical, but they make an interesting argument.
Back in the last century, smart alecks said that commercial fusion would always be 50 years in the future. Now, energy consultant Wood Mackenzie has taken to discussing developments in nuclear fusion as if they might not be far off. A big change in view, considering that even recently, experts figured that harnessing nuclear fusion for commercial purposes was at least fifteen years away. In fact, the best-known international fusion effort, the ITER project based in France, projects an in-service date for its fusion reactor in the early 2040s (fifteen years from now). However, the three fusion development firms mentioned in the Wood, Mackenzie report promised a working, commercially viable fusion reactor, or prototype, within five years. That’s 2031 or 2032. This means they will be competing head-to-head with the first generation of new, small modular reactors (SMRs).
But what these folks are really saying (and we’ll get to specifics in a moment) is that they've solved most of the really big problems with fusion—and they’re ready to start raising money from the public.
Well, I would be one of those smart alecks. And, I'm not so sure I'd put any of my own money into this as an investment; at least, not yet. Small modular fission reactors would still seem to be where the smart money is going.
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There remain, of course, significant engineering challenges to overcome:
The principal engineering challenge stems from the fact that a fusion reaction occurs at temperatures of about 100 million degrees Celsius (about ten times hotter than the center of the sun). First, the energy inputs are enormous. The ITER tokamak reactor, for example, is estimated to require about 100 mws of generation to power its systems. That’s why there’s a concern with net energy gain. Or stated differently, can the reactor produce more energy than it consumes? A bare minimum requirement for any technology to be considered commercial. Second is the challenge of maintaining a so-called stable plasma confinement. Not so easy with gases heated to 100 million degrees operating temperatures. The reactor’s plasma consists of superheated gases (deuterium and tritium) whose nuclei collide and release large amounts of energy. Any sudden cooling of the plasma (from contact with the tokamak walls, for example) causes the chain reaction to stop, and reactor run times are currently measured in seconds. And third, there is the challenge of developing reactor materials that can avoid embrittlement due to the constant, intense neutron radiation, an issue they share with conventional atomic reactors.
Aside from the engineering challenges, a reliable and steady supply of deuterium and, even more difficult, tritium, would seem to be another issue, as much a logistical as an engineering challenge. And with current fusion reactor designs - and remember, none of these reactors have come anywhere near being practical for electricity generation on the grid scale - you need both deuterium and tritium. But we can get it from lithium, of which we have rather a lot.
With current technology, the reaction most readily feasible is between the nuclei of the two heavy forms (isotopes) of hydrogen – deuterium (D) and tritium (T). Each D-T fusion event releases 17.6 MeV (2.8 x 10-12 joule, compared with 200 MeV for a U-235 fission and 3-4 MeV for D-D fusion).a On a mass basis, the D-T fusion reaction releases over four times as much energy as uranium fission. Deuterium occurs naturally in seawater (30 grams per cubic metre), which makes it very abundant relative to other energy resources. Tritium occurs naturally only in trace quantities (produced by cosmic rays) and is radioactive, with a half-life of around 12 years. Usable quantities can be made in a conventional nuclear reactor, or in the present context, bred in a fusion system from lithium. Lithium is found in large quantities (30 parts per million) in the Earth's crust and in weaker concentrations in the sea.
Sure seems to me that the SMRs, some designs of which are already deploying, are the better way to go right now.
I write this all the time and will continue to do so, because it's true: We solve today's problems with tomorrow's technology. Fusion is, perhaps, a technology of the day after tomorrow. I'm pretty confident that, in time, with enough attention from the high-forehead folks working on this, practical fusion reactors will power the grid, which by then will hopefully be seriously upgraded and, hopefully, decentralized. And that will be, as someone once said, a big freakin' deal. The climate scolds and "no nukes" people may not like it, any more than they like fission power; they are still, as of this writing, all in on feather-headed notions like covering millions of acres with eagle-killing windmills and solar panels. Those methods are doomed to fail because they just aren't practical on a grid scale, and sooner or later, reality will assert itself.
Nuclear power is the technology for us, for electrical generation: Clean, safe, reliable. Fusion power will probably one day be practical, and when that day comes, it will be a game-changer. But fission power, the new, exciting possibilities around SMRs, they are here now.
Hyman & Tilles conclude:
If the various corporate claims about fusion technologies that we've discussed are even close to being accurate, then there is one thing about which we can be completely certain. This is an industry that will have a very large need for new capital starting this year.
Maybe they are right. I'm skeptical - but maybe they are right. If they are, we may be seeing that game-changer sooner than expected.
