Ingestion doses modeling of long-lived minor actinides 237 Np, 241 Am, and 243 Cm: a comprehensive radiological study

The exploration of nuclear energy as a sustainable, low-carbon alternative to fossil fuels has gained traction due to the urgency of addressing climate change and ensuring energy security. This study evaluates the radiological risks associated with ingestion of the actinides specifically Neptunium-237 (237Np), Americium-241 (241Am), and Curium-243 (243Cm) in nuclear fuel recycling and waste management. The main objective is to model age-specific dose coefficients and estimate cancer mortality and morbidity risks associated with internal exposure pathways. The Radiological Toolbox software was utilized to calculate dose coefficients for various organs. The study integrated biokinetic models, including respiratory and gastrointestinal tract models, to predict the distribution and excretion pathways of radionuclides. Risk assessment was based on coefficients derived from ICRP publications and Federal Guidance Report 13. The results indicate that 241Am and 237Np pose significantly higher internal risks compared to 243Cm due to ingestion, with substantial deposition observed on bone surfaces, the liver, and red marrow. Age-specific analysis reveals that newborns and young children are the most vulnerable demographic, exhibiting higher exposure rates for 241Am and 243Cm than for 237Np. Furthermore, under both low and high LET radiation scenarios, the risks remain elevated. The study underscores that 241Am and 243Cm consistently present the highest internal risks across ingestion pathways. These findings point to the urgent need for advanced biokinetic modeling to better understand radionuclide behavior in the human body and to refine radioactive waste management strategies.