Potential impacts of atmospheric variations on ecological harm resulting from a hypothetical nuclear reactor accident

Simulating catastrophic events and modeling ecological impacts are essential for supporting nuclear safety regulations and informed environmental decision-making. This study uses the HotSpot Health Physics and ERICA software tools to evaluate the ecological consequences associated with a hypothetical release of the core inventory from a small modular nuclear reactor (SMR). By integrating these computational tools, the influence of atmospheric stability on radiological contamination and exposure to biota was investigated. The findings obtained suggest that non-human reference organisms can be used as proxies to evaluate ecological exposure, supporting screening-level assessments of environmental contamination. All modeled organisms are categorized within the terrestrial ecosystem category specified in the ERICA tool, enabling broad comparisons of radiological consequences across different ecological groups. The consequences for terrestrial, aquatic, and aerial organisms vary significantly based on Pasquill-Gifford (PG) stability classes, emphasizing the necessity for species-specific safety protocols. Among the modeled terrestrial organisms, burrowing mammals showed greater variability in exposure levels under different atmospheric stability conditions, while flying insects and mollusks exhibited more consistent dose estimates. By recognizing contamination patterns that depend on ecological contexts, policymakers can refine nuclear safety guidelines to mitigate long-term environmental impacts. These findings may guide crisis response strategies by integrating ecological factors into overall frameworks for management of radiological consequences. Ultimately, the findings highlight the importance of incorporating environmental consequence modeling assessments into nuclear regulatory frameworks to improve the protection of biodiversity while enhancing human safety measures.