Study on Generic Intervention Levels for Protecting the Public in a Nuclear Accident or Radiological Emergency

Large amounts of radioactive material can be released to the environment in a nuclear accident or radiological emergency. In these cases, social and economical factors should be considered in the actions for protecting the public and to recover the environment, as these actions may affect not only the exposed individuals but also the society as a whole, because of the social impact and high costs. In 1994, the International Atomic Energy Agency, IAEA, published the radiological protection principles for intervention criteria in accident situations involving radioactive materials, as well as numeric values for the generic intervention levels, GIL, for the main countermeasures for protecting the public. These GIL values were selected to achieve broadly the maximum net benefit in many accident situations and, nowadays, those principles still represent the international consensus about this matter. On the other hand, the economic differences between countries can lead the optimization process to get GIL values that are quite different from those recommended. In this context, the monetary value of unit collective averted dose, called alpha-value, is a key element for the determination of the GIL. In this work, the method recommended by the IAEA, based on the human capital approach, was used to estimate the alpha-value for Brazil and the value of US$ 3268 per person-sievert was obtained, considering the year 2000 prices. The per capita costs of the countermeasures for protecting the public, as sheltering, evacuation, temporary relocation and permanent resettlement, were estimated and the cost-benefit analysis technique was applied to estimate the respective GIL applicable in the country. Some of the results for the GILs were smaller than those internationally recommended, even the alpha-value being about six times lower than the alpha-value considered by the IAEA. These results were discussed and they were also compared to values estimated by a similar study accomplished for Japan. As the alpha value obtained was much lower than the officially adopted in the country, that is US$ 10,000 per person-sievert, a sensibility study of the results was performed regarding alpha-value. It was also performed a simple analysis of the results considering the per capita costs of the countermeasures. (Author)