Factors Affecting Tritium and 14Carbon Distributions in the Unsaturated Zone Near the Low-Level Radioactive-Waste Burial Site South of Beatty, Nevada


By R.G. Striegl, D.E. Prudic, J.S. Duval, R.W. Healy, E.R. Landa, D.W. Pollock, D.C. Thorstenson, and E.P. Weeks

ABSTRACT

Interpretations of the distributions of tritiated water vapor (HTOv) and 14-carbon dioxide gas (14CO2) concentrations in the unsaturated zone adjacent to the low-level radioactive-waste burial site south of Beatty, Nevada, suggest that observed concentrations of 14CO2 could be explained by either diffusive or advective transport of the radioactive gas from the site. The distribution of HTOv cannot be explained by vapor transport, either by diffusive or advective mechanisms. Thus, liquid transport appears to have played a role in moving HTOv to well UZB-2. Although the process by which this occurred cannot be determined from available data (and indeed may never be known), it is likely that liquid wastes disposed directly into the trenches during the period from 1962 to 1975 contributed to the offsite contamination. Liquid transport may have been enhanced by precipitation and runoff into open trenches that resulted in the occasional accumulation of ponded water in the trenches and flow along preferential pathways in the underlying unsaturated zone.

This abstract was published in U.S. Geological Survey Open-File Report 96-110.