Leaching Studies Using PNL 76-68 Glass Beads and UO sub 2 Rods with Umtanum Basalt and Nugget Sandstone

摘要

We have performed a 440-day leaching experiment, Bead Leach II, using PNL 76-68 glass beads and simulated uranium fuel rods in the presence of repository host rocks. The experiment was conducted in a single pass continuous-flow apparatus consisting of 72 channels. The experimental conditions were: 25 exp 0 C and 75 exp 0 C, flow rates of 1, 10, and 300 m1/d, and leachant solutions consisting of simulated basalt groundwater, brine, and sodium bicarbonate solution. The two host rocks studied were Umtanum basalt and Nugget sandstone. The Bead Leach II experiment began in late 1980 and the leaching phase was concluded in December, 1981. Analysis of the leachates and of the two rock types was carried out subsequently and the results are presented in two reports. Part I was published in March, 1983, and it included results of the leaching of PNL 76-68 glass beads with the basalt groundwater. Part II includes results of the leaching of PNL 76-68 glass beads with brine and bicarbonate solution and the leaching of UO sub 2 pellets with basalt groundwater, brine, and bicarbonate solution. Results are in the form of leach rates, cumulative fractions leached, and adsorption profiles on basalt and sandstone. The radionuclides studied were Pu and Np in the case of the glass beads and uranium in the case of the simulated uranium fuel rods. 5 references, 21 figures, 44 tables. (ERA citation 09:016057)