(Kirk’s note: I’d like to welcome Rick Martin as an author on Energy from Thorium. Rick is a prolific author whom many of you might remember from his WIRED article on thorium. Rick is writing a new book on advanced nuclear technology–keep your eye out for it! Welcome Rick!)

In the wake of the serial failures of cooling and containment systems at the Fukushima Daiichi nuclear power plant in Japan, the public is once again being asked to re-consider the dangers of nuclear power technology. Plenty of the responses have taken predictable courses. At U.S. PIRG (the association of state public-interest groups), the issue is closed: “Unacceptable Risk” is the title of the group’s latest report on nuclear power, which cites “Two Decades of ‘Close Calls,’ Leaks and Other Problems at U.S. Nuclear Reactors.”

Empirically, the actual risks of nuclear power – which tend to be minuscule and spread over thousands of years, as this New York Times story documents – are negligible compared to those of burning fossil fuels, which, based on current trends will unquestionably lead to a disastrous rise in average global temperatures over the next century. Six thousand people died in coal mining accidents in China last year; “In just the past year in the United States, the Deepwater Horizon blowout killed 11 people,” the Times noted, “the Upper Big Branch coal mine blast killed 29 and a natural gas pipeline explosion in California killed 8.” Deaths from accidents at nuclear power plants, 1990-2010: zero.

“Since air pollution from coal burning is estimated to be causing 10,000 deaths per year,” wrote Bernard Cohen, a physics professor at the University of Pittsburgh, in a study of the risks of nuclear power, “there would have to be 25 melt-downs each year for nuclear power to be as dangerous as coal burning.”

But people don’t perceive risks empirically: they respond more to the possibility of sudden catastrophe than to the certainty of prolonged, slow-motion havoc. It’s the plane-crash effect: fear of flying led to hundreds of additional deaths in automobiles in the months after 9/11, and the 32,000 or so people killed every year on U.S. highways rate far smaller headlines than an fatal airline accident that takes the lives of a couple of hundred people. A Chernobyl-sized nuclear accident is much more terrifying, though far less likely, than the gradual desertification of large swathes of the American West.

(It’s also the shark-attack effect: far more people drown in backyard swimming pools every year than die in shark attacks, but nobody ever made a scary movie about stumbling on your kid’s tricycle and hitting your head on the diving board.)

In a column with a familiar headline – “The True Costs of Nuclear Power” – Anne Appelbaum of Slate even trots out a cultural stereotype to justify irrational fears of nuclear power: “If the competent and technologically brilliant Japanese can’t build a completely safe reactor, who can?”

Appelbaum also recycles the hoary argument that the risks of nuclear power make it too expensive. “The cost of … a potential catastrophe is partly reflected in the price of plant construction.”

That’s confusing cause and effect: Building nuclear plants is not costly because of the risk of accident; it’s costly because public perceptions of risk enforce unreasonable licensing delays and add expensive, over-engineered containment systems, and investors price those risks into their funding models.

This sort of thing drives data-driven people – like me, and like many of the readers of this blog – crazy. If the public just had a “better,” more rational perception of risk, we fume, the obvious benefits of nuclear power would win out and the “true costs” of nuclear power would be understood, rather than exaggerated.

That in itself may be a fallacy, though. In 2004 George Gaskell, a professor at the Centre for Analysis of Risk and Regulation at the London School of Economics, wrote a paper along with six other authors looking at the perceptions of risk around genetically modified foods. What they found is that there’s an inverse relationship between the perception of benefits and the understanding of risk: for large numbers of people, “opposition to GM foods arises from a perception of the absence of benefits, a sufficient condition for rejection,” rather than a straightforward perception of risk. When perceived benefits go up, perceived risk goes down.

In other words, your perception of the risks of eating cheeseburgers depends not so much on your understanding of the health dangers of a diet of fatty red meat versus, say, steamed broccoli. It depends on how much you like cheeseburgers.

For supporters of alternative forms of nuclear power, that would seem to open up a public relations opportunity. Advocates of thorium power should focus more on benefits rather than comparative risks, in order to, in theory, shift the debate away from Chernobyl and toward clear skies, global climate stability and verdant forests. Everybody likes cheeseburgers.