Download or read book RESULTS OF THE FY09 ENHANCED DOE HIGH LEVEL WASTE MELTER THROUGHPUT STUDIES AT SRNL written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: High-level waste (HLW) throughput (i.e., the amount of waste processed per unit time) is a function of two critical parameters: waste loading (WL) and melt rate. For the Waste Treatment and Immobilization Plant (WTP) at the Hanford Site and the Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS), increasing HLW throughput would significantly reduce the overall mission life cycle costs for the Department of Energy (DOE). The objective of this task is to develop data, assess property models, and refine or develop the necessary models to support increased WL of HLW at SRS. It is a continuation of the studies initiated in FY07, but is under the specific guidance of a Task Change Request (TCR)/Work Authorization received from DOE headquarters (Project Number RV071301). Using the data generated in FY07, FY08 and historical data, two test matrices (60 glasses total) were developed at the Savannah River National Laboratory (SRNL) in order to generate data in broader compositional regions. These glasses were fabricated and characterized using chemical composition analysis, X-ray Diffraction (XRD), viscosity, liquidus temperature (TL) measurement and durability as defined by the Product Consistency Test (PCT). The results of this study are summarized below: (1) In general, the current durability model predicts the durabilities of higher waste loading glasses quite well. A few of the glasses exhibited poorer durability than predicted. (2) Some of the glasses exhibited anomalous behavior with respect to durability (normalized leachate for boron (NL [B])). The quenched samples of FY09EM21-02, -07 and -21 contained no nepheline or other wasteform affecting crystals, but have unacceptable NL [B] values (> 10 g/L). The ccc sample of FY09EM21-07 has a NL [B] value that is more than one half the value of the quenched sample. These glasses also have lower concentrations of Al2O3 and SiO2. (3) Five of the ccc samples (EM-13, -14, -15, -29 and -30) completely crystallized with both magnetite and nepheline, and still had extremely low NL [B] values. These particular glasses have more CaO present than any of the other glasses in the matrix. It appears that while all of the glasses contain nepheline, the NL [B] values decrease as the CaO concentration increases from 2.3 wt% to 4.3 wt%. A different form of nepheline may be created at higher concentrations of CaO that does not significantly reduce glass durability. (4) The T{sub L} model appears to be under-predicting the measured values of higher waste loading glasses. Trends in T{sub L} with composition are not evident in the data from these studies. (5) A small number of glasses in the FY09 matrix have measured viscosities that are much lower than the viscosity range over which the current model was developed. The decrease in viscosity is due to a higher concentration of non-bridging oxygens (NBO). A high iron concentration is the cause of the increase in NBO. Durability, viscosity and T{sub L} data collected during FY07 and FY09 that specifically targeted higher waste loading glasses was compiled and assessed. It appears that additional data may be required to expand the coverage of the T{sub L} and viscosity models for higher waste loading glasses. In general, the compositional regions of the higher waste loading glasses are very different than those used to develop these models. On the other hand, the current durability model seems to be applicable to the new data. At this time, there is no evidence to modify this model; however additional experimental studies should be conducted to determine the cause of the anomalous durability data.
Download or read book ENHANCED DOE HIGH LEVEL WASTE MELTER THROUGHPUT STUDIES written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Department of Energy has authorized a team of glass formulation and processing experts at the Savannah River National Laboratory (SRNL), the Pacific Northwest National Laboratory (PNNL), and the Vitreous State Laboratory (VSL) at Catholic University of America to develop a systematic approach to increase high level waste melter throughput (by increasing waste loading with minimal or positive impacts on melt rate). This task is aimed at proof-of-principle testing and the development of tools to improve waste loading and melt rate, which will lead to higher waste throughput. Four specific tasks have been proposed to meet these objectives (for details, see WSRC-STI-2007-00483): (1) Integration and Oversight, (2) Crystal Accumulation Modeling (led by PNNL)/Higher Waste Loading Glasses (led by SRNL), (3) Melt Rate Evaluation and Modeling, and (4) Melter Scale Demonstrations. Task 2, Crystal Accumulation Modeling/Higher Waste Loading Glasses is the focus of this report. The objective of this study is to provide supplemental data to support the possible use of alternative melter technologies and/or implementation of alternative process control models or strategies to target higher waste loadings (WLs) for the Defense Waste Processing Facility (DWPF)--ultimately leading to higher waste throughputs and a reduced mission life. The glass selection strategy discussed in this report was developed to gain insight into specific technical issues that could limit or compromise the ability of glass formulation efforts to target higher WLs for future sludge batches at the Savannah River Site (SRS). These technical issues include Al-dissolution, higher TiO2 limits and homogeneity issues for coupled-operations, Al2O3 solubility, and nepheline formation. To address these technical issues, a test matrix of 28 glass compositions has been developed based on 5 different sludge projections for future processing. The glasses will be fabricated and characterized based on the protocols outlined in the SRNL Task and Quality Assurance (QA) plan.
Download or read book MATRIX 2 RESULTS OF THE FY07 ENHANCED DOE HIGH LEVEL WASTE MELTER THROUGHPUT STUDIES AT SRNL written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: High-level waste (HLW) throughput (i.e., the amount of waste processed per unit time) is a function of two critical parameters: waste loading (WL) and melt rate. For the Waste Treatment and Immobilization Plant (WTP) at the Hanford Site and the Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS), increasing HLW throughput would significantly reduce the overall mission life cycle costs for the Department of Energy (DOE). The objective of this study was to generate supplemental validation data that could be used to determine the applicability of the current liquidus temperature (TL) model to expanded DWPF glass composition regions of interest based on higher WLs. Two specific flowsheets were used in this study to provide such insight: (1) Higher WL glasses (45 and 50%) based on future sludge batches that have (and have not) undergone the Al-dissolution process. (2) Coupled operations supported by the Salt Waste Processing Facility (SWPF), which increase the TiO2 concentration in glass to greater than 2 wt%. Glasses were also selected to address technical issues associated with Al2O3 solubility, nepheline formation, and homogeneity issues for coupled operations. A test matrix of 28 glass compositions was developed to provide insight into these issues. The glasses were fabricated and characterized using chemical composition analysis, X-ray Diffraction (XRD), TL measurement and the Product Consistency Test (PCT). The results of this study are summarized below: (1) TiO2 concentrations up to (almost equal to) 3.5 wt% were retained in DWPF type glasses, where retention is defined as the absence of crystalline TiO2 (i.e., unreacted or undissolved) in the as-fabricated glasses. Although this TiO2 content does not bound the projected SWPF high output flowsheet (up to 6 wt% TiO2 may be required in glass), these data demonstrate the potential for increasing the TiO2 limit in glass above the current limit of 2 wt% (based strictly on retention or solubility). (2) For those study glasses that had very close compositional overlap with the model development and/or model validation ranges of the current DWPF TL model (except TiO2 and MgO concentrations), there was very little difference in the predicted and measured TL values. Even though the TiO2 concentrations were above the 2 wt% upper limit, the results indicate that the current T{sub L} model is applicable in this compositional region with TiO2 contents up to approximately 3.5 wt%. (3) As the target glass compositions diverge from the model development and validation ranges, the T{sub L} data suggest that the model under-predicted the measured values. These discrepancies imply that there are individual oxides or oxide combinations that need to be accounted for in the model. These oxides include B2O3, SiO2, MnO, TiO2 and/or their combinations. More data would be required to fill in these anticipated DWPF compositional regions for higher WL glasses so that the model coefficients could be refit to account for these differences. (4) Based on PCT response of HWL-21 and HWL-22 (two glasses that were prone to nepheline formation) it appears that increasing the B2O3 concentration in glass does not consistently suppress the formation of nepheline in glasses with higher Al2O3 and/or Na2O content. Although the chemical durabilities of the quenched versions of these glasses were very acceptable, the canister centerline cooled (ccc) glasses exhibited a considerable decrease in durability and were found to contain nepheline via XRD. In fact, one of the glasses had a release that was 5 times greater than that of the Environmental Assessment (EA) benchmark glass. These results suggest a need for a more fundamental understanding of the compositional and kinetic effects of nepheline formation in high WL glasses. (5) Data have been generated in support of the replacement of the homogeneity constraint with the Al2O3 and/or sum of alkali constraints for coupled operations as previously completed for sludge-only operations. This strategy should be pursued for either the compositional region anticipated for coupled operations or as part of the variability study for each sludge batch. The PCT responses of the study glasses suggest a high probability that this strategy could be defended at some later date.
Download or read book RHEOLOGICAL PROPERTIES OF SAVANNAH RIVER SITE srs RADIOACTIVE HIGH LEVEL WASTES AND MELTER FEEDS FOR SLUDGE BATCH 2 written by and published by . This book was released on 2005 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Savannah River Site, SRS, is currently pursuing an aggressive program to empty its High Level Waste, HLW, tanks and immobilize its radioactive waste into a durable borosilicate glass in the Defense Waste Processing Facility, DWPF. To create a batch of feed for the DWPF, several tanks of sludge slurry are combined into one of the million gallon, i.e. 3.79E06 liters, feed tanks for DWPF. A batch of feed nominally consists of 500,000 gallons, i.e. 1.89E06 liters. After a batch of feed is prepared, a portion of the batch, 26,500 liters, is transferred to DWPF. This batch is then chemically adjusted in the Chemical Processing Cell, CPC, prior to being fed to the melter to make the final product; canisters filled with glass. During the processing of the third batch, or Sludge Batch 2, of feed through the DWPF CPC, pumping and transfer problems were noted. These problems hindered the processing of the feed through the CPC, and thus impacted canister production in DWPF. In order to investigate the root cause of these problems, data were collected and evaluated for possible trends. One trend noted was the relationship between the pH, solids loading concentration, and temperature of the feed. As any one of these three variables changed, the rheological properties of the feed appeared to change. To determine the dependency of the rheological property, samples were obtained and shipped to Savannah River National Laboratory's, SRNL, Shielded Cells Facility. The samples were processed under two sets of conditions and rheological measurements obtained. The results of the SRNL studies showed that the ending pH of the samples impacted the rheological properties of the sample. Lowering the pH of the sludge slurry resulted in lower plastic viscosity and yield stress values, thus alleviating the processing problems. Increasing the solids loading typically increased both the plastic viscosity and yield stress. There was minimal or no dependency on temperature.
Download or read book Recueil Documentation sur Robert Ramard written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Integrated Research Plan written by Canada. Royal Commission on Aboriginal Peoples and published by . This book was released on 1993 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: Outline of research in progress or proposed, on the situation of native peoples in Canada, including governance, economics, treaties and lands, social and cultural topics, the north, women, urban topics, history and youth.
Download or read book Transportation of Used Fuel written by and published by . This book was released on 1992 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pediatric Uroradiology written by R. Fotter and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 770 pages. Available in PDF, EPUB and Kindle. Book excerpt: The text is specifically devoted to pediatric urogenital radiology. It covers all aspects of the subject in great depth, and contains essential information for the pediatrician, pediatric surgeon, and urologist. It is specifically designed to aid the clinician in decisions on imaging management. The technique and current value of all imaging and interventional procedures are presented, and the diverse problems associated with the changing anatomy, physiology, and pathophysiology of the growing organism are explained. Throughout, additional information is provided on operative options, postoperative complications, and clinical and radiological normal values. This book will prove of great interest to all who are involved in caring for children.
