Monday, April 14, 2014

Nuclear reactors and airplanes

It's interesting to watch the different arguments from pro-nuclear and anti-nuclear forces. The pro-nuclear forces point out that building all new power plants as 100% renewable in the near future is completely impractical, but a mixture of renewables and nuclear is. They may point out that coal is the fastest-growing power source in the world, and that in a contest between the environmental impacts of coal and nuclear, there is no contest. They go on to point out the relatively high rate of deaths from coal power (such as direct deaths in coal mines, and indirect deaths from air pollution) per unit of power generated, compared to the few deaths from nuclear. They may even then point out that petroleum power in general has a poor safety record compared to nuclear worldwide.

The anti-nuclear crowd, meanwhile, focuses on a tiny number of accidents like Chernobyl (actually, there is no other accident like Cherlobyl) and a few problematic, but non-lethal, old reactor designs, like this pebble-bed reactor design from the 60s--as if costly problems are unique to the nuclear industry. As if the industry has learned nothing in the last 40 years. As if today's engineers cannot be trusted because previous generations occasionally made mistakes. After all, why pay any attention to accidents, deaths or cost overruns (or air pollution) in fossil-fuel power, when we can simply make every single new power plant a renewable power plant? Never mind that not every place in the world has plentiful sunlight or wind, or that the sun and wind rarely provide consistent and predictable power. They may argue that nuclear power produces too much toxic waste, or that it lasts too long--even though the amount of waste is very small for the amount of energy generated, and even though there are new designs on the horizon which can get 100 times more energy from the same amount of fuel, while simultaneously producing waste that is toxic for just 300 years rather than 3000+ years for older reactors. (okay, you can see which side of the argument I'm on.) They may point out that nuclear reactors can produce material fit for nuclear bombs--but this is largely intentional; there are numerous reactor designs that are poor sources for bomb material, and a couple that are specifically designed to prevent re-use of the fuel in bombs. In any case, in democratic countries it makes a lot more sense to rally against the bombs themselves rather than a potential source of bomb-making material, especially in countries like the U.S. that already have huge stockpiles of bombs.

They then move on to the argument about nuclear that is actually fair: that it often costs more than renewables.

Nuclear faces political and popular opposition, often due to outdated opinions based on a few unsafe reactors from the 60s and 70s (did you know that Fukushima reactor 1 was built before Chernobyl? Or that there is another nearby reactor run by a more safety-conscious company that survived the tsunami?). This opposition and regulatory uncertainty increases costs, plus reactors are traditionally built with the "craftsman" approach where every reactor is large, somewhat unique, and built on-site. It seems to me that costs could be reduced greatly if nuclear reactors were mass-produced like trucks (small reactors seem to work great for nuclear subs!) and distributed around the country from factories, and if they used passive failsafes to make uncontrolled meltdowns "impossible" so that outer containment chambers could be less costly.

But the public opposition is no small barrier to overcome. Remember how a Tesla car makes nationwide news whenever a single battery pack is damaged and catches fire, even though there are 150,000 vehicle fires reported every year in the U.S.? You can expect the same thing with small modular reactors--barring some terrible disaster, all sorts of problems with petroleum power plants will be scarcely noticed, while a single minor nuclear incident will make nationwide headlines. Similarly, despite the many casualties and massive damage inflicted by the enormous earthquake and tsunami in Japan, my news sources have delivered vastly more news about Fukushima (the power plant, not the prefecture) than the rest of the disaster, even though the power plant is a relatively small part of it. Such reporting biases surely make potential nuclear investors nervous.

I think if the aviation industry were maligned the way the nuclear industry is, it would never have gotten off the ground, so to speak. While the raw data would say flying is as safe as driving, if not safer, people would actually believe that flying is more dangerous, so not many people would want to fly. But think about the other effects of negative public opinion: countries would enact laws to prevent flying near cities on the basis that they might crash into a community at any moment. Airports would have be built far from populated areas to keep the flying menaces away, which would decrease even further the number of customers, since they would have to drive a substantial distance to get to the airport in the first place. Due to the low number of customers, flights would cost three or four times as much, and much fewer flights would be available because for some paths there would not be enough customers to run flights weekly, let alone daily.

Finally, although this hypothetical world might have fewer airplane accidents than our world does in absolute terms (because there would be so many fewer planes), flying in this world would actually be more dangerous, because that world hasn't had the opportunity to make tragic mistakes and learn from them. Although at some point they encounter diminishing returns, plane crash investigations generally lead to safer planes. Since air travel is commonplace in our world, we have had enough plane crashes to learn how to make planes that are very safe--not just "on par" with cars, but thousands of times safer. In other words, if people hysterically avoid planes because they believe they are unsafe, in the long run this actually keeps them less safe. Ironically, when you put two different facts together...
  • That people are afraid of flying despite the safety record
  • That people are willing to fly despite their fears
...this probably explains why flying is so safe. If the media treated fatal plane crashes as "ordinary" events like fatal car crashes are, people wouldn't be as afraid of flying, and then the plane builders would have a much smaller incentive to make planes safer. So to reach the maximum safety level, we as a society have to be irrationally afraid of flying, but not so afraid that we stop flying.

So it is in the nuclear industry: if we build very few reactors because there is a tiny chance of disaster, then each reactor we do build will be very expensive and it'll be hard to learn how to make them perfectly safe, because we won't have the benefits of experience. But if we build small reactors in large numbers, we can learn to build them cheaply, and their safety, cost, longevity and efficiency will improve over time (even though, like airplanes, nuclear reactors are already much safer than the most common alternative.)

So if we'd like nuclear power that is cheap and safe, it is clear what we must do: build more reactors!

1 comment:

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