The development of environmental modeling tools in Brazil for emergency preparedness

Since the Goiania accident, in 1987, the IRD is developing tools to support decision-making processes after accidents involving radiological public exposure. The Environmental Modelling Project began with the development of the code CORAL, based on the German dynamic model ECOSYS, developed by the GSF, with the purpose of assessing the consequences of an accidental contamination of rural areas. Then, in cooperation with the GSF, the IRD has developed the model PARATI, based on information from Chernobyl and Goiania accidents, for the assessment of the exposure of the public due to a contamination of Cs-137 in urban areas. This model includes the ability to simulate the implementation of countermeasure and its effectiveness in reducing doses to the public. Subsequently, the SIEM - Integrated Emergency System was developed to include CORAL and PARATI, as well as some generic models developed by the IAEA, for short-term dose estimates and to support protective strategies during the emergency phase of an accident. SIEM also incorporated standardized data on the physical behavior of radionuclides and dose conversion factors. Several improvements have been performed in order to better adequate the model to Brazilian social, political, economic and climatic characteristics. Currently a multi-criteria strategy to support decision-making processes after the occurrence of an event of environmental contamination is under development. That work includes the development of a database on countermeasures and a computer model to perform the multi-criteria simulation. At all stages of the work, the pertinent weather and seasonal aspects are considered, in order to obtain a guide to protective actions accounting for social, economic and climatic characteristics, to be used in multi-criteria optimization processes adequate for tropical climate areas. (author)