Geochemical modeling of solubility and speciation of uranium, neptunium, and plutonium

This technical report presents a comprehensive geochemical modeling study focused on the solubility and speciation of uranium, neptunium, and plutonium, as significant actinides in environmental contexts. The objective was to evaluate the sensitivity of existing models to solubility data while predicting the impact of actinide speciation on the behavior and mobility of these species within the subsurface environment. Methodologically, the study incorporated several modeling approaches, including conceptual and mathematical models, to facilitate a robust analysis of solubility and speciation processes. The report includes a description of model inputs necessary for calculations and their intended applications across various domains. Results demonstrate the critical interplay between solubility data and actinide speciation, underscoring its relevance for environmental safety assessments and radioactive waste management strategies. The findings contribute to a better understanding of the geochemical behavior of actinides under various conditions, thus informing future research and mitigation efforts concerning their environmental impacts.