The sight of Japan's Fukushima #3 nuclear reactor exploding is chilling (Youtube video available here.) When the remaining best-case scenario involves pumping seawater into a nuclear reactor and venting off the radioactive steam in a highly populated area, you have to wonder "how the hell did we get here?"'

Critics have long contended that Japan high level of seismic activity makes it a poor place for nuclear power, while nuclear proponents have been equally confident that it is safe. Judging from the island nation’s dependency on nuclear energy (roughly 1/3 of power generation), it seems clear that the optimists' arguments have (until now) carried the day.

The same confidence in the safety of Japan's nuclear plants led to the loading last fall of a new fuel type called MOX (mixed-oxide) into the core of the Fukushima #3 reactor. In contrast to the Uranium that powers most reactors, MOX is basically a Uranium cocktail spiked with Plutonium. Greenpeace reports that using MOX in a reactor is less safe because "plutonium is more reactive and this hotter fuel can cause increased localised melting of fuel in the reactor." A release or accident is also more severe, since plutonium is one of the nastiest and most toxic substances around, and MOX reactors have a lot more of it.

So what would have prompted officials to make an already risky proposition even riskier? The answer of course is that they don't (or at least didn’t) believe that the risk exists. Overconfidence leads to poor decision making.

Malcom Gladwell wrote a piece on this topic for the New Yorker in 2009, in which he said,

"As we get older and more experienced, we overestimate the accuracy of our judgments, especially when the task before us is difficult and when we’re involved with something of great personal importance. The British were overconfident at Gallipoli not because Gallipoli didn’t matter but, paradoxically, because it did; it was a high-stakes contest, of daunting complexity, and it is often in those circumstances that overconfidence takes root."

With energy demand rising, and the risks of climate change growing, it may turn out that we need nuclear power as one option, as some prominent environmentalists have concluded. But here's an idea…rather than continuing to claim that nucelar power is safe, let's start with the assumption that it isn't, and make decisions accordingly. We need to start thinking about the unthinkable, rather than making unsubstantiatable safety claims.

As was said after the Exxon Valdez spill, and is being demonstrated again in Japan, even million to one shots come in every now and then.

Photo: CC license - some rights reserved by Official U.S. Navy Imagery