Behavior of Water Flow and Radionuclide Migration in Unsaturated Porous Medium

摘要

This paper introduces the research results of unsaturated flow and field radionuclide migration test conducted for two years in loess sediment. Van Genuchten's method was adopted to describe soil-water characteristics and produced an excellent consistency with measurement data of water retention curves. Radionuclide migration test indicated that the loess sediment appeared a strong sorption ability for Co, Sr and Cs. Under natural condition, it would takes over 10~4 years for Sr to travel through a unsaturated zone of 28m thickness at the test site, over 10~6 years for Co and Cs. However, small amounts of Co and Cs were found mcved faster greatly than their concentration peaks.