RESUMO
The Urban Remediation Working Group of the International Atomic Energy Agency's Environmental Modelling for Radiation Safety (EMRAS) programme was established to improve modelling and assessment capabilities for radioactively contaminated urban situations, including the effects of countermeasures. An example of the Working Group's activities is an exercise based on Chernobyl fallout data in Ukraine, which has provided an opportunity to compare predictions among several models and with available measurements, to discuss reasons for discrepancies, and to identify areas where additional information would be helpful.
Assuntos
Cidades , Exposição Ambiental/análise , Exposição Ambiental/prevenção & controle , Modelos Biológicos , Monitoramento de Radiação/métodos , Proteção Radiológica/métodos , Carga Corporal (Radioterapia) , Simulação por Computador , Humanos , Agências Internacionais/organização & administração , Doses de Radiação , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
When investigating the action of microscopic fungi of genera Aspergillus, Alternaria, Cladosporium and Paecilomyces on concrete specimens in the model system, it was shown that the fungi can colonize successfully the concrete surface during 1 year and cause its destructive changes. However the fungi did not colonize those sections of concrete surface which were filled with granite. The fungi leached chemical elements of concrete into nutrition medium, accumulated them in their biomass and caused their transformation into newly-formed crystals of calcium oxalates on the surface of concrete.
Assuntos
Materiais de Construção/análise , Fungos Mitospóricos/crescimento & desenvolvimento , Modelos Biológicos , Alternaria/crescimento & desenvolvimento , Alternaria/metabolismo , Alumínio/metabolismo , Aspergillus/crescimento & desenvolvimento , Aspergillus/metabolismo , Biomassa , Cálcio/metabolismo , Cladosporium/crescimento & desenvolvimento , Cladosporium/metabolismo , Meios de Cultura/química , Ferro/metabolismo , Fungos Mitospóricos/metabolismo , Paecilomyces/crescimento & desenvolvimento , Paecilomyces/metabolismo , Silício/metabolismo , Especificidade da Espécie , Fatores de TempoRESUMO
The Urban Remediation Working Group of the International Atomic Energy Agency's EMRAS (Environmental Modelling for Radiation Safety) program was organized to address issues of remediation assessment modelling for urban areas contaminated with dispersed radionuclides. The present paper describes the first of two modelling exercises, which was based on Chernobyl fallout data in the town of Pripyat, Ukraine. Modelling endpoints for the exercise included radionuclide concentrations and external dose rates at specified locations, contributions to the dose rates from individual surfaces and radionuclides, and annual and cumulative external doses to specified reference individuals. Model predictions were performed for a "no action" situation (with no remedial measures) and for selected countermeasures. The exercise provided a valuable opportunity to compare modelling approaches and parameter values, as well as to compare the predicted effectiveness of various countermeasures with respect to short-term and long-term reduction of predicted doses to people.