Conceptual model for flow separation processes affecting waste package chemical environment, Yucca Mountain, Nevada

A conceptual model for the chemical evolution of near-field water chemistry in the proposed high-level nuclear waste repository at Yucca Mountain, Nevada is presented. This model considers the effects of differential solubility in flowing water that is subject to evaporation or condensation. The results of a simplified numerical implementation of the model are used to predict the aqueous chemistries produced from a variety of source waters under two bounding assumptions of separation. The model predicts that, under some conditions the most soluble ions will not always be present in solution. The more soluble ions may precipitate at different locations than ions of slightly less solubility leading to a highly complex system containing different brine compositions at different locations.