Fusion or Fission – Pick a Horse


In 1920, physicist Arthur Eddington proposed the basis for nuclear fusion power. Referring to the energy contained in nuclear reactions, he said “we sometimes dream that man will one day learn how to release it and use it for his service. The store is well nigh inexhaustible, if only it could be tapped.” In 1955 Homi Bhabha, the architect of India’s nuclear programme, told the first International Conference on Peaceful Uses of Atomic Energy in Geneva “I venture to predict that a method will be found for liberating fusion energy in a controlled manner within the next two decades. When that happens the energy problems of the world will have been solved for ever.”

A century after Eddington, we’re still looking, and nuclear fusion continues to be labelled as the power source that’s always 30 years away.

In 2022, an article in the India Times stated “Researchers at Culham’s Joint European Torus (JET) facility claimed on February 9th that they have released 59 megajoules of sustained energy from nuclear fusion, enough to power a 60-watt light bulb for 11 days, replicating how energy is produced in the Sun”. The JET subsequently surpassed that record, on October 3rd 2023, producing , per the Max Planck Institute, “69 megajoules of fusion energy…in the form of fast neutrons during a 5.2 second plasma discharge.” However, the people at Planck noted (and I, for one, think that this is significant) that “The JET record did not achieve a positive energy balance – in other words, more heating energy had to be invested in the plasma than fusion energy was generated. In fact, an “energy gain” is physically impossible with JET and all other current magnetic fusion experiments worldwideFor a positive energy balance, these fusion plants must exceed a certain size, which will be the case with ITER.” 

In December of 2022, with a technology different from JET,  the National Ignition Facility at the Lawerence Livermore National Laboratory in the US claims to have achieved a net positive energy gain from fusion using a high energy laser to create the intense temperatures required to drive fusion reactions. However, the energy gain was miniscule, and it was over in nanoseconds.  

The JET project began in 1983, and the record setting experiment in October 2023 was its third and last major fusion experiment. JET concluded its scientific operations at the end of December 2023. I’ve been unable to find a reliable estimate of the total investment in the JET over its forty year history. Two specific portions of the construction renovation of JET were listed at approximately half a billion Euros. An October 2014 report to the European Parliament described the ongoing cost of the JET as 50 to 57 million Euros per year. A little math suggests that at least 2.5 Billion euros ($4Bn Canadian) were invested in the JET. That’s a substantial investment for 10 seconds worth of fusion.

More investment is underway. The next big thing is the International Thermonuclear Experimental Reactor (ITER), which is designed to be big enough to produce positive energy gain. Eurofusion reports that “The goal of ITER is to operate with a plasma thermal output of 500 MW (for at least 400 seconds continuously) with less than 50 MW of plasma heating power input. No electricity will be generated at ITER.” The cost of ITER was initially projected to be $5.6 B (US), but an estimate in Wire Science suggests that the cost will be somewhere between 25 and 65 billion US dollars, for a machine that is designed to produce heat (for 400 seconds) but no electricity. The goalposts for that achievement are 11 years way in 2035.

Despite those staggering costs and the lack of an achievement that would impress anyone but Sheldon Cooper, interest in fusion is growing and private capital is pouring into research and development. In 2023, World Nuclear News reported that investment in Fusion had reached $6.2B US spread across 43 different companies. Even though ITER is not scheduled to produce a significant experimental outcome until 2035, they tell us that “The latest survey found that four companies believe they will deliver power to the grid by 2030, and 19 by 2035.” 

One of the companies that has been mentioned in several articles is General Fusion, a Canadian company. Their website says “We are fast tracking our technical progress to provide commercial fusion energy to the grid by the 2030s by building a new magnetized target fusion (MTF) machine in Richmond, British Columbia. Called Lawson Machine 26 – LM26 – the machine is designed to achieve fusion conditions of over 100 million degrees Celsius by 2025, with a goal of achieving breakeven by 2026.”  Funding from a number of sources for General Fusion topped $430M by 2021. It reported a $5M grant from the BC government in 2023, as well as federal government funding totalling $54M.

To claim that we’re doing nuclear fusion R&D is to be very kind and generous to the fusion community. There’s no significant development going on. We’re still seriously bogged down in the research phase only. There is no industry consensus on the shape of a reactor (donut shaped tokamak, “cored apple” shape, weirdly twisted stellarator). The fuel might be deuterium, it might be deuterium/tritium mix, it might be boron/hydrogen mix. The big physics problem is to create, confine and control a plasma and that might be done by magnetic confinement, by inertial confinement, or by magnetized target fusion (the General Fusion model). Getting the energy out of the reactor onto the grid might be accomplished by the direct generation of an electric current, or it might be accomplished by extracting heat from the 100 million degree C plasma. We really haven’t got any idea of how to engineer a practical power facility – we’re still working on the underlying science.

Fusion industry voices tend to agree that companies who are raising money for further research are being wildly optimistic about the future generation of electricity from fusion. “All this optimism should be viewed cautiously, especially from companies that need to raise capital for future experiments” says the Economist. An article in Scientific American has a number of quotes from Ian Chapman, CEO of the U.K. Atomic Energy Authority (UKAEA), the British government’s nuclear energy organization. ““Experiments are making progress, and the progress is impressive, but fusion is not going to be working [as a source of mass energy] in a few years’ time… fusion plants might be feeding power into the grid by around 2050 and then could become steadily more important to the energy economy in the second half of the century, especially post-2060.”

Tony Donné, EUROfusion’s program manager is a little more blunt. “Anyone who tells me that they’ll have a working future reactor in five or 10 years is either completely ignorant or a liar.”

Conclusion? Fusion power is still that wonderful energy source that’s 30 (40?,50?) years away. My generation will not live long enough to see a fusion reactor harnessed to the grid and producing electricity. My kids had better live long and healthy lives if they want to see that happen. My grandchildren? Maybe.

We’re trying hard because fusion is lauded as an inexhaustible energy source, with virtually zero emissions and no radiation problems. But, those assumptions are open to challenge. 

First of all, some of the potential reactor designs would produce an intense flux of highly energetic neutrons. Those neutrons pose two significant problems. They have the potential to create activation products, which, while shorter lived and less dangerous than fission fuel products, will nevertheless result in radioactive wastes. The myth that fusion produces helium atoms and no radiation is, in almost all possible designs, unachievable.  Also, the neutrons bombarding the materials of the reactor will cause microscopic melting and recrystallization within the metal lattice of the reactor chamber walls, weakening the structures. Chapman of the UK says “We don’t know and won’t know about materials degradation and lifetime until we’ve operated a power plant”.

Second, some of the methods proposed in managing the intense heat of the fusion reactor core are pretty demanding. We’re talking about generating temperatures of 100 million degrees and then trying to extract energy from that. There are proposals to cool reactors with liquid nitrogen in huge volumes, or even with liquid Helium. There are potential reactor designs in which liquid lithium is used as part of the reactor boundary. Can you imagine the consequences of springing a leak in a vessel filled with liquid lithium? 

The World Nuclear Association captures the engineering problems thusly: “ the challenge is to apply the heat to human needs, primarily generating electricity. The energy density of fusion reactions in gas is very much less than for fission reactions in solid fuel, and as noted the heat yield per reaction is 70 times less. Hence thermonuclear fusion will always have a much lower power density than nuclear fission, which means that any fusion reactor needs to be larger and therefore more costly, than a fission reactor of the same power output. In addition, nuclear fission reactors use solid fuel which is denser than a thermonuclear plasma, so the energy released is more concentrated. Also the neutron energy from fusion is higher than from fission – 14.1 MeV instead of about 2 MeV, which presents significant challenges regarding structural materials.”

Whatever the final design of a fusion reactor is, it’s unlikely to be a nice simple industrial process. I like the “keep it simple, stupid” principle, and I don’t see that anywhere in nuclear fusion.

I understand the appeal of fusion. But while we’re chasing the elusive dream of fusion power, we need to ask how we are going to power the world to minimize greenhouse gases. Because the truth is that fusion will make no meaningful contribution to achieving net zero emissions by 2050. 

The answer of course is that while we’re chasing the elusive fusion dream, we need to be powering the world with fission power. As of February 2024, the World Nuclear Association reports that there are 436 nuclear reactors in operation with about 393,000 MWe of installed capacity providing about 10% of the world’s electricity. There are currently projects in progress to build a further 65000 MWe of capacity. Interest in new nuclear power is growing in Canada. We’re exploring small modular reactors at Darlington. We’re pursuing refurbishment of four units at Pickering, and the Ontario government is interested in building next generation nuclear units at Bruce. All I can say is that it’s about time. 

And why not?

Fission power is emissions free. The greenhouse gas emissions from fission plants, like hypothetical fusion plants, are negligible.

We’re not about to run out of Uranium. The World Nuclear Associations says “The world’s present measured resources of uranium (6.1 Mt) in the cost category less than three times present spot prices and used only in conventional reactors, are enough to last for about 90 years. This represents a higher level of assured resources than is normal for most minerals. Further exploration and higher prices will certainly, on the basis of present geological knowledge, yield further resources as present ones are used up. And in addition to the current known supply, of which Canada has a nice portion, there is the potential to reclaim fissile materials from previously irradiated (spent) fuel to power another generation of reactors. So it might not be inexhaustible, but it’s not a near-term, or even a mid-term concern.

And where the jury is still out on the practicality of fusion (it might never happen, you know), it’s clear that fission power, while not yet perfect, is very practical.

There are two reasons that are commonly proposed for not investing in, and relying upon, nuclear fission.

The first argument is that nuclear reactors are unsafe. They might melt down; OMG, they might kill us all!  So yes, nuclear reactor accidents have happened. Three mile Island, Chernobyl and Fukashima, are all real accidents with significant and damaging results. I don’t mean to downplay those events. However, I would point out that the world is still spinning, with some 7 billion relatively healthy humans on board. The worst nuclear plant accident ever, Chernobyl, resulted in an access exclusion zone of approximately 1000 square miles, about ¼ of the area that was permanently flooded by the wonderful, beautifully clean, environmentally green, James Bay hydro-electric project.

Further, I would point out that nuclear power has been in service for about sixty years. It’s a known technology. Lessons have been learned from Three Mile island, from Chernobyl and especially from Fukashima. There is no reason to believe that the next hundred years of nuclear power cannot be better managed than the first sixty years when the industry was on a steep learning curve. 

The airline industry is one where a somewhat risky and dangerous technology (flight) was adopted. Airline fatalities were recorded at about 500 fatalities per year in the 1940’s. They rose steadily as traffic volume increased, to a peak at about 1800 fatalities per year in 1972. Since then fatalities have decreased steadily to a value of about 150 (five year rolling average) in 2020. Should we not expect fission power to exhibit a similar event profile?

Despite the fact that airlines are a much safer way to travel than automobiles, some people are still paranoid about flying because airline accidents, when they happen, are so dramatic. And despite the fact that nuclear power produces reliable, clean, emissions free energy, some people are still paranoid about nuclear energy because accidents, when they happen, are so dramatic.

The other reason that is commonly held up as a reason not to build more new nuclear reactors is that we’re creating a radiation hazard that has to be managed for thousands of years. My response to that is that this was a valid argument in 1950, but it’s irrelevant now. Banning fission power now is a case of closing the barn door after the horse has gone.

In 1950 there was virtually no nuclear waste on the planet, and several countries, Canada among them, were researching nuclear power. At that point, a decision might have been made to avoid the problem of nuclear wastes. But since then we’ve built and operated more than 500 nuclear power plants worldwide. We’ve already got the problem of managing used fuel. Letting that problem double or triple or quadruple in size isn’t a terribly big issue. Even after sixty years, there’s not a lot of high level waste around. The WNA suggests that in the UK, “after all waste has been packaged, it is estimated that the final volume would occupy a space similar to that of a large, modern soccer stadium.” Storing nuclear wastes far underground in deep geologic repositories is a technology that is firmly believed to provide safe storage. The problems with developing such storage are not really technical. They are “not in my backyard (NIMBY)” political. The bottom line is that we already own that problem and we’re not going to make it significantly harder to manage, so we might as well exploit the technology further to power the world in a zero emissions way. 

Fusion is like that beautiful thoroughbred horse that can run like the wind if you can only tame it and ride it. Fission is the team of Clydesdales you’re using to plough the back forty. That thoroughbred’s a beautiful horse, but he ain’t getting the job done. Better get more reliable, hardworking Clydesdales.


5 responses to “Fusion or Fission – Pick a Horse”

  1. Well, the first half of this enlightenment left me in a state of con-fusion where I remain but for the other interpretation of my term.

    • Thanks for the comment Joe…I think. Perhaps you might explain the “but for the other interpretation of my term” part of your comment.

    • I’m not against fusion. But I think it’s a pipe dream in anything near term. Everybody talking about what a wonderful future fusion means is really trying to pump for funding.

      Dennis

  2. A very nice essay, Dennis. The case for funding fusion is pretty weak. Certainly I would not like to see Cdn government funding being poured down that rabbit hole. It is interesting though that private investment is supporting fusion research; private investors are usually pretty tight-fisted. So maybe there’s some hope of a return on investment.
    I like the argument about storing the spent fusion fuel ; we have that issue and more reactors won’t make it worse. One issue that you didn’t address is the apparent (to me anyway) exorbitant cost of building and operating nuclear power plants. Is this due to corruption in the (government?) contracting process, incompetence in the industrial construction complex, or the inflated pay scales in the nuclear industry? (I am floating this last issue as a point of discussion not as a proven fact.).
    Bottom line, I would not invest tax dollars or my dollars in fusion.

    • Thanks for the comment Terry. Let me start with your bottom line comment first. Canadian government funding is being poured into the fusion project already. My research indicates that we have about $60 million of government funding in General Fusion. I’m not personally distressed by that number. I think there is significant benefit from doing scientific research of any sort. I’m not sure that it will produce fusion power. But it may produce something, and it may sustain the scientific community, which would be a good thing.

      The reasons for the cost of nuclear power is a good question. One significant reason is that everything about a nuclear power construction comes with a very rigourous quality assurance program. The time and energy put into documenting every weld is significant. The bigger reason is the carrying cost of money for long construction schedules. Schedules are coming down. The Japanese now constructing plants in a 5 to 6 year timeframe. That’s still a lot of time to be accruing interest on construction capital costs. The solutions appear to be small modular reactors, and relying on cookie cutter designs for larger models.

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