Glass Property Models and Constraints for Estimating the Glass to be Produced at Hanford by Implementing Current Advanced Glass Formulation Efforts
Recent glass formulation and melter testing data have suggested that significant increases in waste loading in high-level waste (HLW) and low-activity waste (LAW) glasses are possible over current system planning estimates. The data (although limited in some cases) were evaluated to determine a set of constraints and models that could be used to estimate the maximum loading of specific waste compositions in glass. It is recommended that these models and constraints be used to estimate the
... estimate the likely HLW and LAW glass volumes that would result if the current glass formulation studies are successfully completed. It is recognized that some of the models are preliminary in nature and will change in the coming years. In addition, the models do not currently address the prediction uncertainties that would be required before they could be used in plant operations. The models and constraints are only meant to give an indication of rough glass volumes and are not intended to be used in plant operation or waste form qualification activities. A current research program is in place to develop the data, models, and uncertainty descriptions for that purpose. A fundamental tenet underlying the research reported in this document is the attempt to be less conservative than previous studies when developing constraints for the estimation of glass to be produced by implementing current advanced glass formulation efforts. The less conservative approach documented herein should allow for the estimate of glass masses that may be realized if the current efforts in advanced glass formulations are completed over the coming years, and are as successful as early indications suggest they may be. Because of this approach, there is an unquantifiable uncertainty in the ultimate glass volume projections due to model prediction uncertainties that must be considered, along with other system uncertainties, such as waste compositions and amounts to be immobilized, split factors between LAW and HLW, etc. v Summary Efforts are being made to increase the loading of Hanford tank wastes in glass while maintaining adequate processability, regulatory compliance, and product quality. These efforts have significantly expanded the composition regions and waste loadings of glasses beyond the point used in current project planning models. The effort documented in this report is aimed at evaluating the current glass formulation, property, and processing data, and to use the data to develop a non-conservative set of constraints and property models that can be used to estimate the amount of glass that would be produced at Hanford if the current advanced waste glass formulation efforts were to be successfully completed according to current plans. An accurate method of estimating glass volume to be produced from Hanford tank waste is important for making informed decisions regarding the appropriate process options to pursue, as well as estimating the likely cost and schedule for tank waste cleanup mission completion. To help gain an accurate estimate of glass volume, glass property, processing, and composition, data have been gathered from literature including the results of the ongoing advanced glass formulation program being led by the U.S. Department of Energy Office of River Protection with support from the Vitreous State Laboratory at The Catholic University of America and the Pacific Northwest National Laboratory. These data have been evaluated and used in the development of preliminary glass composition-property models as well as property and composition constraints. By combining these models and constraint sets, the reader can estimate the minimum amount of glass to be generated from Hanford tank waste with a given composition. Example calculations are supplied to ensure that the calculations are performed as intended. The models and constraints are only meant to give an indication of rough glass volumes and are not intended to be used in plant operation or waste form qualification activities. A current research program is in place to develop the data, models, and uncertainty descriptions for that purpose. Throughout this document, a number of model coefficients and other values are reported with a higher number of figures than are significant. Ideally, the appropriate number of figures to report should be evaluated in detail. However, no such evaluation was performed. We therefore suggest using all reported figures in the model coefficients for consistency with example calculations supplied in this report.