Why Nuclear Fusion is Worthy of Further Research and Government Investment
Last week, I spent two days at the International Atomic Energy Agency’s 2012 Fusion Energy Conference in San Diego. The conference, sponsored by the U.S. Department of Energy’s Office of Science and General Atomics, brought together about 1000 fusion scientists from around the world to meet and discuss the state of the art in scientific research to develop fusion energy.
Fusion is a technology that holds great promise in meeting our energy needs. By fusing together two hydrogen isotopes – deuterium and tritium – enormous amounts of energy can be produced, as predicted by Einstein’s equation, E=MC2. The heat from this reaction creates steam to spin a generator just like any other electricity power plant. Since deuterium comes from ocean water, and tritium can be bred from lithium, fusion holds the promise of providing a nearly inexhaustible supply of energy, with no pollutants, no greenhouse gases, and no radioactive waste. There is no threat of a nuclear meltdown like there is with the nuclear fission reactors of today.
This is the same process that powers the sun, and it could completely revolutionize the energy system when commercialized. However, the problem is that it is fiendishly hard to initiate a reaction anywhere other than under the tremendous gravitational force of a star. Scientists have not been able to confine the heated plasma on earth in such a way that it creates a reaction that generates more power than it put in – a term called “ignition” or “energy gain.” For more detail, see ASP’s ‘mini-site’ on fusion.
Most of the presentations at the conference were above the scientific knowledge of the average person (they were certainly well beyond my understanding!). However, I am convinced by my experience there that the scientists believe they are now on a pathway to energy gain.
While in San Diego, I took a tour of General Atomics’ DIII-D fusion machine, one of only 3 tokamaks (the donut-shaped reactor designed to confine plasma for the purposes of generating fusion) in the country. The DIII-D has revolutionized the science of containing and controlling the plasma in which a fusion reaction takes place. When operational, the DIII-D fires an experimental 5 second “shot” of plasma through the machine. It was down for maintenance while I was there.
Critics of fusion often say that it is the energy of the future and always will be. However, I would point out that the DIII-D was originally built in the 1960s, and was last substantially upgraded in 1986. Similar trajectories can be noted at the other major American research facilities, like MIT and Princeton. Throughout the 90s, and into today, there have been plans for new machines that could lead to breakthroughs, but persistent budget cuts have prevented new advances.
Even so, scientists at the conference seemed convinced that they are on a pathway to achieving ignition with energy gain over the next decade or two. These predictions are dependent upon the level of government funding – not an easy or guaranteed thing at this time – and some scientific breakthroughs. The ITER project in Cadarache, France promises to achieve energy gain when it is operational by the end of this decade.
Fusion is not tomorrow’s energy source, and I am not advocating that we put all our energy research and development eggs in this one basket, but in a world with a population growing towards 9 billion people, with economic growth and prosperity directly linked with the use of finite fossil fuel resources, we must plan for alternative energy sources. Renewable resources can meet some of those needs, but they will become increasingly difficult to mesh with our modern energy grid as their levels get higher. The presentations I saw last week convinced me that there are many hurdles before the ultimate goal, but that the scientists are on their way. With the quality of the minds working on it, and with the clear benefit that limitless power would bring, this seems like a “Hail-Mary” pass that we should be investing in. Someday, we will realize fusion as a limitless, safe, clean energy. If America does not invest in it, other nations will, and we’ll be forced to buy it from them.
I will have future posts on the state of the budget for American fusion, and progress towards fusion in smaller, privately-funded companies. I should also direct readers to my most recent article up on AOL Energy that discusses Lawrence Livermore’s National Ignition Facility, and why the New York Times’ editorial page was wrong to attack it.
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Unfortunately, even with the budget that we do have, the US is largely investing in only a single avenue of fusion research.
The tokamak magnetic confinement approach is certainly the best understood and most highly developed of the possible fusion energy schemes, and you obviously understand the laser inertial confinement being investigated at NIF. These projects are clearly “big science”, which may be why the feds pay attention to them.
But there are a handful of other projects, which have the interesting property that, while their chances of success are quite a bit lower than the big science projects, their funding requirements are hundreds or even thousands of times lower. These include magnetized liner inertial fusion, several private and academic magnetized target fusion efforts, dense plasma focus fusion, and scads of inertial electrostatic confinement approaches.
The odds of success for a couple of these are pretty decent, and then there are a whole bunch of long shots. But most of these experiments are limping along on tiny amounts of money. Even a couple million dollars of grant money to each would allow most of them to complete their experimental agenda. If none of them pan out, we haven’t lost much. But if even one of them looks promising, then we would have some backup plans in case the tokamak approach doesn’t pan out.
And there are plenty of obstacles on which the tokamak folks could run aground: Nobody knows how to make tritium in industrial quantities. The deuterium-tritium reaction is incredibly hard on the tokamak itself, because it’s bombarding exotic materials with fast neutrons, so the longevity of a tokamak reactor is a problem. The operational details of how a tokamak is coupled with a steam plant and run continuously and reliably for generating electricity are far from understood. And, ultimately, the enormous scale that tokamak reactors require, with plants producing tens or even hundreds of gigawatts of electricity, makes financing them and locating them very difficult.
Maybe solar, wind, and biofuel will find ways to scale up, and nuclear energy will become an odd historical footnote. But all of the low-energy-density renewable plans are at least as fraught with technical and economic problems as fusion is. And, unlike the other renewables, if you solve the fusion problem correctly, the next time you have to worry about energy technology from a national (or international) security standpoint is many hundreds of years away. So having a couple of different irons in the fusion fire seems only prudent.
The deuterium-tritium reaction is not the only possibility; and it is not as safe as you imply. Tritium is radioactive and expensive, and the reaction produces neutrons -inherently deadly, and they irradiate surrounding materials, weakening them, and making them radioactive. The p-B11 (hydrogen-Boron) reaction has NO radioactive reactants or products and involves NO neutrons whatever. The polywell mechanism required for making this happen is MUCH cheaper than the tokamak. It would be operating today, if it weren’t for a foolish little turf war between the Navy and the US Department of Energy.