Avaliação de risco radiológico e radioepidemiológico em centros urbanos: simulação de um incidente nuclear hipotético em uma cidade litorânea

Abstract

uclear accidents release large quantities of radioactive materials into the atmosphere, exposing the population to radiation doses and contamination. Given the threat of accidental and/or intentional radiological events, it is essential to employ tools that aid in decisionmaking for risk analysis and the protection of the occupationally exposed population. This study presents an in-depth assessment of the effects of a hypothetical nuclear incident involving an LWR reactor in the city of Aracaju, accounting for the population and affected area. The analysis of the event is based on the Pasquill-Gifford classification of atmospheric stability (PG Classes) at the time, the prevailing wind direction, and census data on the individuals. Simulations were performed using the HotSpot Health Physics Code v3.1.2 software to determine the Total Equivalent Effective Dose (TEDE) and the Excess Relative Risk (ERR) associated with radiation-induced cancers, such as leukemia. The estimates considered low-dose radioepidemiological models, Biological Effects of Ionizing Radiation (BEIR) V and VII, and vulnerability criteria such as age and sex, analyzing groups of males, females, children, and the elderly in the affected areas. To collect population data, Geographic Information Systems (GIS) were used to delineate impacted zones and groups, and information from the National Institute of Meteorology (INMET) was used to assess wind patterns. The results indicated variations between exposure and risk, attributed to local atmospheric conditions and wind direction, predominantly from the East-Southeast (ESE) and Southeast (SE). The expansion of isodoses is explained by the capital’s flat and rugged terrain, combined with PG classes and wind direction. The study highlights the importance of geospatial models for demographic analysis, census data, and informed decisions about the exposed population.