10/29/2010 05:25 pm ET Updated May 25, 2011

Nuclear Power Ambivalence: the Fears and the Facts

Germany's ambivalence about nuclear power, common in many developed countries, is again on display following the decision by Chancellor Merkel and the Bundestag to extend the operating life of the nation's 17 nuclear plants for an average of 12 years beyond their currently scheduled closure dates. Merkel says this will help Germany develop the "most efficient and environmental friendly energy supply worldwide." Protestors in Berlin say their government is "...selling safety for money."

Both sides in the decades-long disagreement over nuclear power argue the facts. But underneath this is really an argument about how those facts feel. Risk perception, about nuclear power or genetically modified food or vaccines or any potential threat, is never a purely rational fact-based process. Decades of research has found that risk perception is an affective combination of both facts and fears, intellect and instinct, reason and gut reaction. It is an inescapably subjective process which has helped us survive but which sometimes gets us into more trouble, because we often worry too much about relatively smaller risks, or not enough about bigger ones, and make choices that feel right, but actually create new risks all by themselves.

So the current German experience, reflective of ambivalence about nuclear power around the world, teaches important lessons, not about nuclear power per se, but about how we perceive risk in the first place, because understanding that subjective system is the first step toward avoiding its pitfalls.

Consider the two aspects of the risk of nuclear radiation; the facts, and the feelings.

Nearly 90,000 hibakusha, the name in Japan for atomic bomb survivors who were within 3 kilometers of the explosions, have been followed for 65 years. Scientists compared them to a non-exposed Japanese population, to calculate the effects of the radiation. The current estimate is that just 572 hibakusha have died, or will die, from various forms of radiation-induced cancer. A little more than half of one percent.

Research by the International Radiation Effects Research Foundation (RERF) also found that the fetuses of hibakusha women pregnant when they were exposed to radiation were born with horrible birth defects but little other serious long-term health damage from exposure to those extraordinarily high levels of radiation has been found, not even genetic damage.

Based on the hibakusha research, the World Health Organization estimates that of several hundred thousand people exposed to ionizing radiation from Chernobyl, over the entire lifetime of that population, as many as 4,000 might die prematurely from cancer caused by the radiation. Tragic, of course, but like the number of cancer deaths among survivors of the nuclear bombs, a smaller number than many people assume.

So if we know that, yes, ionizing radiation is a carcinogen, but a relative weak one, why is nuclear power so scary? Research into how people perceive and respond to risk has identified several psychological characteristics that make nuclear radiation particularly frightening;

  • It's undetectable by our senses, which makes us feel powerless to protect
  • ourselves, and a lack of control makes any risk more frightening.
  • Radiation causes cancer, a particularly painful outcome, and the more
  • pain and suffering something causes the more afraid of it we are likely to be.
  • Radiation from nuclear power is human-made, and human-made risks evoke
  • more fear than natural threats. (Radiation from the sun kills roughly 15,000 Europeans per year from skin cancer).
  • Nuclear power plants can have accidents like Chernobyl (and many still believe
  • they can explode like bombs), and people are intrinsically more afraid of risks associated with singular large scale "catastrophic" events than risks which cause more harm, but where the harm is chronic, spread out over space and time.
  • Many people don't trust the nuclear industry, or government nuclear regulators, and the less we trust the more we fear.

But public attitudes toward nuclear power are shifting. The psychology of risk perception explains that too.

  • We are more aware of the benefits of CO2-free emissions, and when the benefits of a choice seem larger, the associated risks seem smaller.
  • Chernobyl, 1986 was fresher in European minds in 2000 when Germany voted to eliminate all nuclear power by 2021, than now, a decade later, and the less immediately aware of a risk we are, the less fear it evokes.

These psychological factors have nothing to do with the facts about the actual risk of nuclear radiation. But, as is often the case with perception of risk, these emotional filters, more than the facts, determine how afraid we are, or aren't. It's pointless to argue whether this is rational or irrational, wrong or right. This is, inescapably, how it is. Respect it though we must, however, we also have to realize that this affective process can be a danger all by itself. Our fear of nuclear power has led to energy economics that favor coal and oil for electricity. At great cost to human and environmental health. Particulate pollution from fossil fuels kills hundreds of thousands of people a year, and CO2 emissions are fueling a potentially disastrous shift in the global climate.

No amount of education or good risk communication can get around this. Subjective perception is hard wired into the neural architecture and chemistry of the human brain. What governments around the world can do is to learn what the science of risk perception psychology has taught us; that our perceptions, as real as they are and as much as they must be respected in a democracy, can create new perils in and of themselves. With that understanding, government risk assessment can account for not only the facts of a risk but how we feel about them, and how we behave, and by factoring both aspects into a more holistic view, hopefully achieve less conflict over nuclear power and all risk issues, and wiser and more productive policies for public and environmental health.

(This is an updated version of a piece that first ran on Project Syndicate)