Should nuclear fusion be considered a green energy source?
Thanks to Treehugger for reminding me to blog about the cover story of National Geographic‘s August issue: Powering the Future. I’m sure some Gristmillians will find flaws in some of the article’s assertions and statistics, but as Treehugger Michael Richard notes, it seems to be a good introductory piece for the uninitiated.
Here is how the section for fusion starts off:
Fusion is the gaudiest of hopes, the fire of the stars in the human hearth. Produced when two atoms fuse into one, fusion energy could satisfy huge chunks of future demand. The fuel would last millennia. Fusion would produce no long-lived radioactive waste and nothing for terrorists or governments to turn into weapons. It also requires some of the most complex machinery on Earth.
From what I read in NG, there seems to be no downside to fusion, assuming you can actually make it work. So, I headed over to the indispensable Wikipedia and dug a little deeper.On the likelihood of an accident:
… a catastrophic accident in a fusion reactor in which injury or loss of life occurs is much smaller than that of a fission reactor. The primary reason is that the fuel contained in the reaction chamber is only enough to sustain the reaction for about a minute, whereas a fission reactor contains about a year’s supply of fuel.
On effluents, this: “The natural product of the fusion reaction is a small amount of helium, which is completely harmless to life and does not contribute to global warming.”
On waste management:
The large flux of high-energy neutrons in a reactor will make the structural materials radioactive. The radioactive inventory at shut-down may be comparable to that of a fission reactor, but there are important differences. The half-life of the radioisotopes produced by fusion tend to be less than those from fission, so that the inventory decreases more rapidly … Such materials would have half-lives of tens of years, rather than the thousands of years for radioactive waste produced from fission …
And as the NG article pointed out:
Although fusion power uses nuclear technology, the overlap with nuclear weapons technology is small. Tritium is a component of the trigger of hydrogen bombs, but not a major problem in production. The copious neutrons from a fusion reactor could be used to breed plutonium for an atomic bomb, but not without extensive redesign of the reactor, so that clandestine production would be easy to detect. The theoretical and computational tools needed for hydrogen bomb design are closely related to those needed for inertial confinement fusion, but have very little in common with (the more promising) magnetic confinement fusion.
So, acknowledging that fusion is a far, far, far ways off, I’m wondering what Grist readers think of this option. Does it belong under the clean and/or renewable energy banner? Did I miss anything in my ten minutes of research (I’ve got web pages to code, you know)?