Nuclear Power PlantCarefully conducted analysis conducted over a multiyear study suggests that expanding evacuation zones around nuclear power plants may increase the risk of latent cancer fatalities (LCF) in the unlikely event of an accident that releases radioactive material.

This slightly counterintuitive conclusion is not news anywhere else, but I came across a nugget buried deep in a lengthy report that led me to decide to produce a short blog on the topic. This post more early morning musing than the result of any particular initiating event in world.

While researching a response associated with an Atomic Insights conversation thread, I reviewed the concluding paragraphs of the State of the Art Reactor Consequence Analysis (SOARCA) report that was issued by the US Nuclear Regulatory Commission as NUREG-1935 in November 2012.

Though I was looking for something else, this paragraph caught my eye.

Analysis of Figure 15 and 16 also shows that expanding the evacuation size from a 10 mile radius to a 20 mile radius results in increased LCF risk for people in the 0-10 mile area. SOARCA analyses show that an evacuation beyond the area closest to the plant will delay those most at risk, i.e., closest to the plant. The increased risk to the population within 10 miles of the plant is due to slower evacuation speeds because of additional traffic congestion and delays that result from evacuation of a larger population.


It is not hard to imagine how this kind of thing can happen if people panic instead of responding rationally and carefully evaluating potential risks. Think, for example, about how the world wide supply of potassium iodine tablets was strained after Fukushima because people on the west coast of North America decided that they needed to rush out and purchase protection from radioactive iodine that had no chance of reaching them in sufficient quantities to cause any harm.

The self-centered people who overreacted and assumed they were at risk may have added a small amount of risk for the people who were close enough to the place where the releases took place to be able to receive some benefit from taking the KI tablets to reduce exposure to their thyroids from I-131.

The SOARCA model result of the effect of a 20 mile evacuation zone would be even worse if the researchers had considered the possibility that panic driven politicians might decide to increase evacuation zones to 50 miles.

If moving the people within 20 miles causes slowdowns for the most affected population who are closest to an accident, just think what would happen if the government tried to force everyone within 50 miles to of any given location to start moving at the same time. Don’t forget the fact that a wider imposed panic circle also increases the amount of travel required before an evacuee can feel safe – at least according to the information provided by supposed experts who thought that a 50 mile evacuation was reasonable in the first place.

This situation provides more support for my contention that actions that some assume are “conservative” can have unintended consequences that harm more people than actions that are perceived to be more moderate.