Demonstration of sulfur solubility determinations in high waste loading, low-activity waste glasses

[摘要] A method recommended by Pacific Northwest National Laboratory (PNNL) for sulfate solubility determinations in simulated low-activity waste glasses was demonstrated using three compositions from a recent Hanford high waste loading glass study. Sodium and sulfate concentrations in the glasses increased after each re-melting step. Visual observations of the glasses during the re-melting process reflected the changes in composition. The measured compositions showed that the glasses met the targeted values. The amount of SO₃ retained in the glasses after washing was relatively high, ranging from 1.6 to 2.6 weight percent (wt %). Measured SnO₂ concentrations were notably low in all of the study glasses. The composition of the wash solutions should be measured in future work to determine whether SnO₂ is present with the excess sulfate washed from the glass. Increases in batch size and the amount of sodium sulfate added did not have a measureable impact on the amount of sulfate retained in the glass, although this was tested for only a single glass composition. A batch size of 250 g and a sodium sulfate addition targeting 7 wt %, as recommended by PNNL, will be used in future experiments.

[发布日期] 2016-04-25

[学科分类] 核能源与工程

[关键词] SODIUM SULFATES;GLASS;TIN OXIDES;SULFUR;LOW-LEVEL RADIOACTIVE WASTES;CONCENTRATION RATIO;SODIUM;SOLUTIONS;MELTING;SOLUBILITY;ABUNDANCE;WASHING;SIMULATION;CHEMICA