Hydrothermal Interaction Studies of Bullfrog Member Tuff Core Wafers in J-13 Water at 150 exp 0 C: Quantitative Analyses of Aqueous and Solid Phases

摘要

This paper describes the experimental work conducted to understand the water chemistry in the near-field surrounding a nuclear waste repository in the Bullfrog Member of the Crater Flat Tuff, Nev., and to study any changes in the rock itself due to hydrothermal alteration. The work is part of the Nevada Nuclear Waste Storage Investigations (NNWSI) Project to determine the suitability of the volcanic units at Yucca Mountain for storing high-level nuclear wastes. Static hydrothermal experiments with polished core wafers were run for 60 d; all faces of the core wafers were exposed to solution. Quantitative solution analyses indicate that the solution chemistry for both crushed tuff and solid core wafers is in good agreement. Analyses of the solid phases suggest that the extent of reaction, at least over the 60-d period, is relatively minor, even though solution effects were observed. These experiments show that conditions in a repository located in the Bullfrog Member would be relatively benign with respect to waste form and waste package survival. 4 references 10 figures, 4 tables. (ERA citation 09:032741)