Laboratory studies of radionuclide distributions between selected groundwaters and geologic media. Annual report, October 1, 1978-September 30, 1979

Abstract

Extensive studies of the behavior of plutonium and americium in pH approx. = 8 groundwaters were made, particularly with respect to container sorption, filtering, and centrifugation. Significant improvements in the method used for measuring sorption ratios for these elements were developed, and their sorption-desorption ratios on argillite and tuff were measured. Effects of particle size, temperature, sampling location, mineralogy, and time were investigated for these elements. The chemical composition of the water was found to be a major factor that governs sorption behavior. Studies of the sorption of strontion, cesium, barium, cerium, europium, uranium, and americium on Hainesville salt dome materials were made under aerobic and anoxic (<0.2 ppM oxygen) conditions using two synthetic groundwaters: one represented the Wilcox aquifer in the Hainesville region and the second was a dilute brine. Studies of the sorption of strontium, cesium, barium, cerium, europium, and uranium(VI) on granite and argillite were made under anoxic (<0.2 ppM oxygen) conditions and the results were compared to earlier measurements made under aerobic conditions. The sorption of uranium(VI) on argillite under atmospheric conditions was investigated. Measurements of migration rates in crushed granite, argillite, and tuff were made and compared with batch results. Infiltration experiments involving the forcedmore » injection of activity into intact and fractured cores were also performed. Microautoradiographic techniques were used to detect specific sorption sites. This latter technique was also used to characterize the sorption of plutonium and neptunium on polished thin-sections of alluvium, granite, tuff, and argillite and to assess the amount of aggregation that occurred. Additional physical and chemical characterizations of the materials used in these studies were made, and new analytical techniques were developed.« less