Status report for the Small-Tube Lysimeter Facility, fiscal year 1990.

摘要

Westinghouse Hanford Company and Pacific Northwest Laboratory are jointly developing earthen protective barriers for the near surface disposal of radioactive and hazardous waste. The proposed barrier design consists of soil overlying a sequence of layers. The experiments were designed to measure the influence of erosion control practices and alternative barrier layering configurations on water movement within the barrier. This report describes the results of nearly 2 full years of data collection. Four concurrent experiments are being performed; each experiment is designed to test different components of the barrier. The results of this study are summarized: (1)Surface Treatment Effects -- All three main factors (surface treatment, precipitation, and vegetation) had significant effects on both water storage change and cumulative evapotranspiration. (2) Layering Sequence Effects -- There were no significant storage or evapotranspiration differences between the bimodal and graded subsurface layering treatments. (3) Surface Sand and Gravel Effects -- A sand deposition layer was found to have a similar effect on soil column water balance as a gravel mulch layer. Drainage was detected from both. (4) Alternative Barrier Effects -- There were no significant storage or evapotranspiration differences between the clay and grout treatments. All barrier configurations except those with a surface layer of sand or gravel prevented drainage. This result indicates that the barrier will prevent water infiltration. If a gravel admix surface erodes to form a gravel mulch or if sands are deposited on the barrier surface, then infiltration may be possible. 15 refs., 31 figs., 3 tabs.