Nuclear Reactors 529 - New Study Suggests That Evacuation May Not Be Beneficial For Major Nuclear Accidents
The Nuclear Regulatory Commission has a set of rules for where people should be evacuated in case of a nuclear accident in which radioactive materials are released. While the exact plan for emergency procedures is tailored to each site depending on geography, wind, and other conditions, there are general rules for considering evacuation. Everyone in a two-mile radius of the accident site should be evacuated. In addition, there should be an evacuation of everyone downwind of the accident out to five miles from the site. Some critics of the rules for evacuation are raising questions about its necessity.
Delving into the dangers of nuclear accidents that may affect the life expectancy of someone who may be exposed to radioactive materials, there is a measure called “Change of life expectancy from averting a radiation exposure” or CLEARE. This can tell you how much a specific amount of radiation will reduce your estimated lifespan on average. On the other hand, the costs of evacuations should be taken into account as well. In order to measure these costs, a method called the judgement or J-value has been developed. This basically tells you how much quality of life people are willing to sacrifice in order to increase their remaining life expectancy. Eventually everyone reaches a point where they are no longer willing to pay the cost of a longer life with reduced quality.
The J-value can be calculated for a particular country. First you find out what the average of the gross domestic product is per person. Then risk aversion can be computed based on information about work and life balance. When this information is entered in the J-value model, you wind up with the maximum amount that a person will be willing to pay for a longer life expectancy.
Following the 2011 Fukushima disaster in Japan, more than one hundred and ten thousand people were immediately evacuated. Another fifty thousand left voluntarily. Four and a half years later, eighty-five thousand had not returned. When the new J-value was applied to that evacuatioin, it was estimated that exposure to the radioactive emissions from the disaster would have reduced the life expectancies of the evacuees by about three months. This suggests that the cost of evacuation was much higher than any expected benefit for the evacuees. It turns out that the average loss of life expectancy in London, England due to the air pollution is about four and a half months but no one is suggesting that people evacuate the city because of it.
The J-value system was also used to assess the decision to evacuate people after the world worst nuclear accident at Chernobyl nuclear power plant in Ukraine in 1986. Over one hundred thousand people were permanently evacuated in 1986 and another two hundred and twenty thousand people were evacuated in 1990. The J-value model suggested that people should only have been evacuated if their radiation exposure reduced their average life expectancy by nine months. It turns out that only thirty-one thousand people out of the three hundred and thirty six thousand evacuees would have suffered such a reduction of life expectancy. That amounts to less than ten percent.
Researchers at the University of Manchester in England investigated the J-value model in application to hundreds of possible big nuclear reactor accidents all over the world. Their findings indicated that none of the cases they studied would benefit from evacuation.
In addition to questions of life expectancy, there are also psychological impacts. When the media is saturated with dire warnings in the aftermath of a nuclear accident, many people believe that they are in much greater danger than is really the case. All in all, the requirement for evacuation after a major nuclear accident needs to be reexamined and perhaps radically altered.
