{sup 36}Cl measurements of the unsaturated zone flux at Yucca Mountain

Determining the unsaturated zone percolation rate, or flux, is an extremely important site characterization issue for the proposed Yucca Mountain nuclear waste repository. A new technique that measures the {sup 36}Cl content of tuff from the Exploratory Shaft will be used to calculate flux through the unsaturated zone over longer times than could be measured by the more conventional {sup 14}C method. Measurements of the {sup 36}Cl "bomb pulse" in soil samples from Yucca Mountain have been used to confirm that infiltration is not an important recharge mechanism. 5 refs., 3 figs