Sun in a Bottle - Charles Seife [108]
The community seems to be in thrall to a collective delusion. Since the early 1950s, physicists have convinced themselves that fusion energy is nearly within their grasp. The perennially overoptimistic Edward Teller thought that within a few years, hydrogen bombs would carve canals, propel spacecraft, and generate almost unlimited amounts of energy. Lyman Spitzer thought powerful magnetic fields would create an artificial star within a decade. The ZETA team thought they had achieved fusion in 1958, freeing the planet from its dependence on fossil fuels. Laser fusion scientists thought that Shiva would produce energy, and that Nova would produce energy. Wrong, wrong, wrong. The history of fusion energy remained a series of failures.
Even if scientists finally change their luck, even if NIF breaks even and ITER manages to get a plasma burning for minutes at a time, both machines are still far from becoming working fusion reactors. NIF’s design, particularly its slow lasers that need to cool for hours between shots, suggests that researchers will have to move to an entirely different type of laser system to have any hope of a practical energy source. ITER will never achieve ignition and sustained burn, the hallmark of a successful magnetic fusion reactor.
It is entirely possible that after billions of dollars and decades of research, fusion scientists will take the experimental results from ITER and turn them into a design for a viable fusion reactor. No physical law stands against it, after all. But if history is any guide, a long, long road lies ahead before physicists will be able to tame fusion reactions in a bottle.
Once they succeed, will it mean anything? Though aficionados are quick to tout fusion energy as the clean, unlimited energy source of the future, it is unlikely to be terribly clean or even terribly practical. The radioactive waste it generates is somewhat easier to deal with than the corresponding waste from a fission power plant, but it is a problem nonetheless. Fusion is also expensive. ITER is likely to cost $15 billion or more to build and run, and it won’t ever be a practical reactor. Even with mass production, each fusion power plant will probably cost many billions of dollars. So long as there are other energy sources available, fusion is unlikely to make a huge dent in humanity’s energy needs.
A better candidate, despite its unpopularity, is fission. Compare it to fusion. Both have a waste problem. Fission’s is more severe, but not by much, at least in the near future. Fission plants are expensive, but they are likely to be considerably cheaper than their fusion counterparts. Fission plants are more dangerous than fusion plants (the fission reaction can get out of control, and a fusion reaction almost certainly won’t), and malefactors can process spent fuel rods to get materials for atom bombs. However, new designs (such as pebble-bed reactors) reduce the risks dramatically. Fission plants don’t have an unlimited source of fuel, but they do have enough for a century or two. And while fusion might be the energy source of the future, fission technology is already here.
Fission may not be the answer to humanity’s energy needs; we might well have to turn to fusion in the more distant future. Nevertheless, from a purely practical point of view, fission seems to be a more reasonable solution than fusion, at least in the short term. Other, non-nuclear, possibilities exist as well. For example, if we figure out how to trap and sequester carbon dioxide, we might be able to burn coal and methane without releasing greenhouse gases. Carbon sequestration schemes and advanced fission reactor designs aren’t sexy, cutting-edge science, but they are much more likely than fusion to help the next few generations of humans.
Even so, the fusion community clings to the hope that fusion energy is just thirty years away—and that it will solve all our energy