Nuclear power is probably mankind's only real hope of weaning our civilization off fossil fuels in time to avert runaway global warming.

By nuclear power I don't mean the first or second-generation reactors, the type that you might associate with Fukushima or Chernobyl.  I'm referring to fourth and possibly fifth-generation technologies such as the IFR, integrated fast reactor.

You can't evaluate nuclear power rationally if you're saddled with irrational fears.   As David Ropeik recently explained in The New York Times, much of our fear of nuclear power is rooted in the dynamics of risk perception, not reality.

Though it has worked well enough to get us this far down evolution’s challenging road, our risk perception system, which blends thinking and feeling and mostly takes place subconsciously, often produces fears that fly in the face of the facts.  Many of us are more afraid of some risks — like mercury or pesticides or genetically modified food — than the evidence warrants. And many of us aren’t as concerned about some really dire dangers as we ought to be, like climate change, particulate pollution or acidification of the ocean  The problem is, being too afraid, or not afraid enough — a phenomenon I call “the perception gap” — produces dangers all by itself.

research on risk perception, by Paul Slovic, Baruch Fischhoff and others[1], has identified several emotional characteristics — fear factors, if you will — that make risks feel more or less frightening, the statistical probabilities notwithstanding. Here are just a few;

• Human-made risks upset us more than risks which are natural.
• Risks imposed on us are scarier than those we take by choice.
• Risks grow scarier the greater the pain and suffering they cause.

Consider how those factors contribute to a perception gap about nuclear power. Nuclear radiation is human-made, which is one reason it’s scarier than radiation from the sun (which kills 12,000 Americans a year).  Radiation from meltdowns like the ones at Chernobyl or Fukushima is imposed on us (many Americans unreasonably worried last spring about a radioactive cloud blowing in from Japan), so it scares us more than the much higher doses of radiation to which we willingly expose ourselves for medical diagnostics or treatment. And nuclear radiation causes cancer, which often causes great pain and suffering.

 It’s not as though this form of radiation isn’t dangerous. It is. But we know from studies of atomic bomb survivors in Hiroshima and Nagasaki, the hibakusha, who have been followed for two generations, that even at high doses for prolonged periods of exposure, nuclear (ionizing) radiation just isn’t the carcinogen most fear. It raised the cancer death rate for those survivors only about half of 1 percent. And while it caused birth defects in children exposed during fetal development, Godzilla and Moth Ra notwithstanding, it didn’t cause multigenerational genetic damage at all.

But given the subjective, instinctive, facts-and-feelings nature of risk perception, it is entirely understandable that nuclear power evokes fear so deep and strong that when people learn about studies of the hibakusha, many simply refuse to believe those well-established facts.

Consider, however, how that fear can be dangerous all by itself. Fear of nuclear power has contributed to energy policy that favors fossil fuels. Burning coal to make electricity produces particulate pollution that kills thousands each year. 

But why the Integrated Fast Reactor option?   There are several reasons.   One is that it's a very peaceful technology.   IFRs don't produce waste that can be turned into weapons grade materials.  Another is that IFRs produce little radioactive waste and what there is has a comparatively very brief life.  Third, and perhaps most important, is that we already have abundant fuel for IFR reactors.

IFR reactors can consume those "spent" reactor rods we're looking to store safely somehow for the rest of their thousands of years of life.  Early reactors were able to extract anywhere from just 3 to 5% of the radiation energy in those fuel rods.  That's why they're so dangerous and stay that way for so long.   IFRs can literally consume those  supposedly spent rods and extract their remaining energy.  Britain has worked out it has enough spent rod energy that IFRs could provide that country's entire energy needs for a century. IFRs are also a dandy way to burn weapons-grade materials from deactivated nuclear arsenals.  That's neat when you want that stuff not to fall into the hands of terrorists.

But we'll never have IFR technology so long as we're blinded by fears of nuclear dangers that never truly existed.   We have to overcome our irrational fears and, for that, time is not on our side.