At Consumer Energy Report, Andrew Holland writes Why Nuclear Fusion is Worthy of Further Research and Government Investment, which is yet another article about the promise of nuclear fusion. He makes a good summation of what we have been told about fusion since the 1950s:
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.”
Mr Holland has returned from a conference where everyone requires a lot more funding.
Critics of fusion often say that it is the energy of the future and always will be. However … 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.
Now, with all respect to Mr Holland, reading this opus (couldn’t resist) didn’t change my opinion in the slightest. In January 2012 Tom Murphy dealt with the problems of Nuclear Fusion and concluded that after sixty years, fusion was “the definition of hard.” I wrote Hot and Cold Running Fusion back in March 2012, and quoted Ugo Bardi:
Now, of course, it is impossible to say that tokamaks will never produce useful energy. But look at the figure at the beginning of this post. Doesn’t it make you wonder? It looks like we are just making the same machine bigger and bigger, in the hope that, eventually, it will work.
I did find something new while scanning the comments. I expected that someone would suggest LENR/cold fusion instead (which happened), that someone would suggest solar energy instead (which happened), and that someone would insist that hot fusion would never amount to anything (which also happened). I didn’t expect that anyone would still endorse the very old Project Plowshares idea of exploding hydrogen bombs in underground chambers, an extension of which is the also very old PACER concept. What was new was that Maury Markowitz cited fears of fusion radioactivity in his provocative article, Why fusion will never happen:
… boy do we need fusion! It’s unlimited, safe, clean, and cheap. It’s the perfect source of power. Except it’s not, well, any of those things.
Markowitz claims that deuterium and thorium are expensive to obtain, and that tritium doesn’t last very long. Markowitz claims that fusion reactors will create a lot of radioactive waste, which I’ve never heard mentioned before. Markowitz claims that if the liquid lithium barrier should ever catch fire, the tritium could burn with oxygen, evaporate and fall as radioactive rain. In footnotes, Markowitz cites The Trouble With Fusion, an 1983 article by MIT Prof Lawrence Lidsky, who then switched from fusion research to fission research. From a 2002 obituary:
“Larry Lidsky was one of the smartest people I ever met,” said Professor Jeffrey P. Freidberg, head of the MIT Department of Nuclear Engineering. “He was often way ahead of his time in delivering insightful and crucial analysis of the prospects of both fusion and fission power. In the fusion area, Professor Lidsky was one of the earliest engineers to point out some of the very, very difficult engineering challenges facing the program and how these challenges would affect the ultimate desirability of fusion energy. As one might imagine, his messages were not always warmly received initially, but they have nevertheless stood the test of time.”
So what did Lidsky say? A PDF of the Trouble With Fusion is available, and Lidsky essentially makes a case for yet-to-be-designed, neutron-free fission reactors instead of large fusion reactors emitting heavy neutrons:
The most serious difficulty concerns the very high energy neutrons released in the deuterium-tritium (D-T) reaction. These uncharged nuclear particles damage the reactor structure and make it radioactive. A chain of undesirable effects ensures that any reactor employing D-T fusion will be a large, complex, expensive, and unreliable source of power. That is hardly preferable to present-day fission reactors, much less the improved fission reactors that are almost sure to come.
Lidsky notes the challenges in obtaining fuel and in working with lithium, but seems to dismiss one of Markowitz’s concerns, noting that tritium is only weakly radioactive and does not linger in the body. Lidsky does, however, note that there will be so much radioactivity inside a fusion reactor that maintenance workers will not be able to service it. Repairs would have to be carried out by robots (who after stealing our jobs will conquer the world).
Lidsky was hardly the only one to criticize fusion, there have been many criticisms and many rebuttals back and forth, but the issues usually seem to boil down to complexity and cost. MSM articles on fusion, though, rarely mention radioactivity at all, implying that fusion reactors are actually much cleaner and safer than the fission reactors that have failed often enough to engender widespread opposition.