Why is Fusion Power is Always 50 Years Away?

Many promising nuclear fusion technologies have come and gone.

Episode Summary: 

The old joke has always been that nuclear fusion is 50 years away. And always will be. The sad reality is that it’s true. No technology has offered so much, absorbed so much research and development and delivered so little progress toward usable hardware. Why? Jim Anderton discusses the subject and his opinions may be controversial.

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Transcript of this week’s show: 

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Most of us have seen the movie Back to the Future, and a little joke embedded in the film like an Easter egg always struck me as funny. Dr. Brown, played by the great Christopher Lloyd, returns from the future driving a DeLorean powered by a coffee maker sized device called “Mr. Fusion”. It’s especially poignant considering how many times we’ve heard that practical fusion power is just around the corner. It’s complex, but for those of you who haven’t been following this long and grinding development, nuclear fusion is in a sense the opposite of nuclear fission. Energy is released by fusing two light atomic nuclei into a heavier one, rather than splitting heavy elements like uranium or plutonium in a controlled chain reaction, something we call fission. All fission and fusion can generate huge amounts of energy, but fusion has distinct advantages both in potential power output and in safety. Fission is about controlling a potentially runaway process, while fusion is about forcing two nuclei together, something they are very reluctant to do. It’s not that nuclear fusion is not well understood. Quite the opposite. Practical nuclear fusion is an engineering problem. The primary issue is that the temperature of the high-energy plasma formed to force those reluctant nuclei together is hot, damned hot. In a typical tokamak, like the Joint European Torus, it’s about 150 million Celsius degrees, making the Sun look cool by comparison. Nothing can contain it, so must be suspended and bottled with ultra powerful magnetic fields. This means superconducting electromagnets, which have their own engineering challenges in large-scale, as well as a vast amounts of power needed to get the reaction going. To accommodate these needs in a system that’s scaled to deliver meaningful amounts of net energy, meaning commercially viable electricity, requires a massive reactor in a big, big facilities. And that takes a lot of the most important reactant in fusion energy, money. The biggest project in the field today, the eight-nation consortium ITER, is building a 500 MW test reactor bottling that hot plasma with a peak magnetic field strength of a colossal 11.8 T. For those of you keeping score, that’s something like 10,000 times the field strength of a fridge magnet. Even more colossal is the cost of the project: at the start of the project in 2006, the estimated cost was about €6 billion over 10 years. By 2008, the cost was revised upwards to 19 billion euros. By 2016, the figure exceeded €22 billion and the price is rising all the time. The amounts are so colossal that to manage the individual participating nations contributions they created their own currency called ITER Units of Account. Keep in mind there is absently no guarantee that any of this will produce a commercially viable reactor. It will however produce a great deal of science, which is great but it’s a very, very expensive way of training PhD’s and postdoctoral fellows. In the meantime, a relative cottage industry of much smaller projects are looking at alternate ways of achieving the same goal. In Canada, General Fusion is developing novel mechanical approach involving steam driven pistons generating shockwaves in a spinning ball of liquid metal. Lawrenceville Plasma Physics in New Jersey has a unique device using a principal they call “focus fusion” that aids plasma containment with a self generated magnetic field. Lockheed Martin’s famed Skunk Works is working on a Navy funded small reactor project, and many others are in the game, with concepts like fusor, polywell and others. No one has suggested that they’re close to a workable commercially practical design. I’m not suggesting that this work should stop, but at some point, if this industry doesn’t start to show some engineering test results that lead to commercially viable power production, the combination of low cost solar, low-cost batteries and low loss transmission using those same superconductors may fill the market atomic fusion was designed to serve. The Chinese are reporting dramatic results. In fusion power, dramatic is plasma containment times on the order of 100 seconds. Even a three order of magnitude improvement on that figure will not produce a workable machine. The fusion community needs to put on the roller-skates, because time is running out. And eventually the money will too.

Written by

James Anderton

Jim Anderton is the Director of Content for ENGINEERING.com. Mr. Anderton was formerly editor of Canadian Metalworking Magazine and has contributed to a wide range of print and on-line publications, including Design Engineering, Canadian Plastics, Service Station and Garage Management, Autovision, and the National Post. He also brings prior industry experience in quality and part design for a Tier One automotive supplier.