(11b) Process Chemistry Improvements in Saltcake Dissolution Modeling– A Retrospective

In 1997, the Process Chemistry for Waste Processing group was formed at the Diagnostic Instrumentation and Analysis Laboratory (DIAL; now the Institute for Clean Energy Technology) at Mississippi State University.  Initial efforts of the group focused on working with Hanford site personnel to identify process chemistry needs to improve the reliability and accuracy of predictions of saltcake retrieval strategies using the Environmental Simulation Program (ESP, OLI Systems, Inc.).  At the 222-S Laboratory at Hanford, Herting[1]judiciously selected saltcake core samples from tanks with differing waste inventory and performed ‘saltcake dissolution’ testing over the next few years.  Based on the results of these dissolution experiments, simulation of the experiments using the ESP software allowed chemical systems to be identified where the predictive behavior and experimental measurements differed significantly.  These select chemical systems were then examined in the ICET laboratory, with solubility experiments conducted under the high ionic strength conditions present in the Hanford waste tanks.  The gathered data for all chemical systems examined in the ICET laboratory have now been incorporated into the Mixed Solvent Electrolyte (MSE) database within ESP.  A comparison of the early predictions with the predictions now possible within the MSE framework of ESP for these saltcakes of differing composition will be presented.