Monday, March 14, 2011

The Fukushima "black swan"


Before Black Swan became a household word as a movie with a dark theme and a lesbian kiss, it was already being used as a metaphor for an extremely unlikely risk, popularized by The Black Swan: The Impact of the Highly Improbable (2007) by Nassim Nicholas Taleb.

Risk calculations involve not only the likelihood of doing well versus doing poorly, but also assumptions about what those are likely to mean. Consumers make such assumptions, with varying degrees of consciousness and care in evaluation, when buying insurance. A homeowner far from any earthquake zone would likely calculate that the possibility of an earthquake was extremely low, and the likely damage if any to the house would be small. Homeowners living a mile from a major seismic fault will presumably recognize a much higher likelihood of both an earthquake event and potentially large damages from one of them. For the homeowner far from an earthquake zone, an earthquake would be a "black swan" event, i.e., extremely unlikely.

The crisis at the Fukushima power plant in Japan in the wake of last week's earthquake and tsunami has once again dramatized the very real risks in nuclear power. Calculating risks in nuclear power also require some calculation of risk. A big challenge with nuclear power risk calculations is that while the risk of a catastrophic event can be greatly mitigated, the effects of a catastrophic event occurring can be huge. This affects the economics of nuclear power because even unlikely risks impose significant costs in terms of safety features that have to be built into nuclear power plants. That factor is largely responsible for the wildly optimistic expectations in the 1950s worldwide that nuclear energy could provide cheap and abundant power.

Mother Jones' environmental reporter Kate Sheppard explains (Japan's Nuclear Emergency 03/12/2011; 6:22 update) that in the current Japanese crisis, we saw an overlapping of risk events:

Several people have asked me what this incident says about whether nuclear plants are built to withstand earthquakes. Plants are supposed to be able to handle the anticipated quake intensity and likelihood relevant to their location, but it appears that this quake in Japan was far stronger than anticipated. Moreover, the problem here looks to be more of a power supply issue, a secondary effect of the quake and tsunami. It's the combination of events that created the bigger problem here. As Ellen Vancko, the nuclear energy project manager for the Union of Concerned Scientists and a former staffer at the North American Electric Reliability Council told me earlier today, "The one lesson we can draw from Japan is no matter how technologically advanced we are as a society, it's virtually impossible to plan for every curveball Mother Nature is going to throw at us." That said, it's probably not a great idea to put a nuclear power plant on an active fault line. [my emphasis]
And, from The Automatic Earth blog via Business Insider, How Black Is The Japanese Nuclear Swan? 03/14/2011. This writer winds up arguing that the risk at Fukushima was foreseeable enough that it should not be characterized as a black swan event:

Proponents argue that the energy returned on energy invested (EROEI) for nuclear power is sufficient to power our societies, that nuclear power can be scaled up quickly enough as fossil fuel supplies decline, that there will be sufficient uranium reserves for a massive expansion of capacity, that nuclear is the only option for reducing carbon dioxide emissions, and that nuclear power can be operated with no safety concerns through probabilistic safety assessment (PSA).

I disagree with all these assertions. Looking at the full life-cycle energy inputs for nuclear power, it seems to be barely above the minimum EROEI for maintaining society, and the costs (in both money and energy terms) are front-loaded.

Scaling up nuclear capacity takes extraordinary amounts of both money and time. While construction can be speeded up, where this has been done (as it was in Russia), the deleterious effect on construction standards was significant. Uranium reserves, especially the high-grade ores, are depleting rapidly. The reduction in carbon dioxide emissions over the full life-cycle do not impress me. In addition, nuclear authorities make risk decisions without informing the public. They have consistently made risk calculations that have grossly underestimated the potential for accidents of the kind that can have generational impacts.

In my view, nuclear power represents an unjustified faith in the power of human societies to control extremely complex technologies over the very long term. Any activity requiring a great deal of complex and cooperative control will do badly in difficult economic times.

Also, no human society has ever lasted for as long as nuclear waste must be looked after. It needs to be held in pools on site for perhaps a hundred years in order to cool down enough for permanent disposal, assuming a form of permanent disposal could be conceived of, approved and developed. During this period, the knowledge as to how this must be done will need to be maintained, and this may be more difficult than is currently supposed.

We need to evaluate the potential for a nuclear future in light of the disaster in Japan. This was not unpredictable, and should have been accounted for in any realistic assessment of nuclear potential. It cannot realistically be described as a black swan event. [my emphasis]
Many countries are likely to rely on nuclear energy for decades to come even in the best of circumstances. Oil companies can use an increased public perception of nuclear plant risks to promote the promise of cheap oil via further deregulation of their drilling onshore and offshore. But the risks or real. And the public should demand that regulators take full account of them.

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