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Rheology of Savannah River Site Tank 51 HLW radioactive sludge

Description: Savannah River Site (SRS) Tank 51 HLW radioactive sludge represents a major portion of the first batch of sludge to be vitrified in the Defense Waste Processing Facility (DWPF) at SRS. The rheological properties of Tank 51 sludge will determine if the waste sludge can be pumped by the current DWPF process cell pump design and the homogeneity of melter feed slurries. The rheological properties of Tank 51 sludge and sludge/frit slurries at various solids concentrations were measured remotely in the Shielded Cells Operations (SCO) at the Savannah River Technology Center (SRTC) using a modified Haake Rotovisco viscometer system. Rheological properties of Tank 51 radioactive sludge/Frit 202 slurries increased drastically when the solids content was above 41 wt %. The yield stresses of Tank 51 sludge and sludge/frit slurries fall within the limits of the DWPF equipment design basis. The apparent viscosities also fall within the DWPF design basis for sludge consistency. All the results indicate that Tank 51 waste sludge and sludge/frit slurries are pumpable throughout the DWPF processes based on the current process cell pump design, and should produce homogeneous melter feed slurries.
Date: January 1, 1993
Creator: Ha, B.C.
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Partner: UNT Libraries Government Documents Department

Nuclear criticality safety analysis summary report: The S-area defense waste processing facility

Description: The S-Area Defense Waste Processing Facility (DWPF) can process all of the high level radioactive wastes currently stored at the Savannah River Site with negligible risk of nuclear criticality. The characteristics which make the DWPF critically safe are: (1) abundance of neutron absorbers in the waste feeds; (2) and low concentration of fissionable material. This report documents the criticality safety arguments for the S-Area DWPF process as required by DOE orders to characterize and to justify the low potential for criticality. It documents that the nature of the waste feeds and the nature of the DWPF process chemistry preclude criticality.
Date: October 21, 1994
Creator: Ha, B. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Rheology of Savannah River Site Tank 51 HLW radioactive sludge. Revision 1

Description: Savannah River Site (SRS) Tank 51 HLW radioactive sludge represents a major portion of the first batch of sludge to be vitrified in the Defense Waste Processing Facility (DWPF) at SRS. The rheological properties of Tank 51 sludge will determine if the waste sludge can be pumped by the current DWPF process cell pump design and the homogeneity of melter feed slurries. The rheological properties of Tank 51 sludge and sludge/frit slurries at various solids concentrations were measured remotely in the Shielded Cells Operations (SCO) at the Savannah River Technology Center (SRTC) using a modified Haake Rotovisco viscometer system. Rheological properties of Tank 51 radioactive sludge/Frit 202 slurries increased drastically when the solids content was above 41 wt %. The yield stresses of Tank 51 sludge and sludge/frit slurries fall within the limits of the DWPF equipment design basis. The apparent viscosities also fall within the DWPF design basis for sludge consistency. All the results indicate that Tank 51 waste sludge and sludge/frit slurries are pumpable throughout the DWPF processes based on the current process cell pump design, and should produce homogeneous melter feed slurries.
Date: March 1, 1993
Creator: Ha, B. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

Assessment of nuclear safety and nuclear criticality potential in the Defense Waste Processing Facility. Revision 1

Description: The S-Area Defense Waste Processing Facility (DWPF) will initially process Batch 1 sludge in the sludge-only processing mode, with simulated non-radioactive Precipitate Hydrolysis, Aqueous (PHA) product, without the risk of nuclear criticality. The dilute concentration of fissile material in the sludge combined with excess of neutron absorbers during normal operations make criticality throughout the whole process incredible. Subsequent batches of the DWPF involving radioactive precipitate slurry and PHA will require additional analysis. Any abnormal or upset process operations, which are not considered in this report and could potentially separate fissile material, must be individually evaluated. Scheduled maintenance operation procedures are not considered to be abnormal.
Date: July 20, 1993
Creator: Ha, B. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Assessment of nuclear safety and nuclear criticality potential in the Defense Waste Processing Facility

Description: A panel of experts in the fields of process engineering, process chemistry, and safety analysis met together on January 26, 1993, and February 19, 1993, to discuss nuclear safety and nuclear criticality potential in the Defense Waste Processing Facility (DWPF) processes. Nuclear safety issues and possibilities of nuclear criticality incidents in the DWPF were examined in depth. The discussion started at the receipt of slurry feeds: The Low Point Pump Pit Precipitate Tank (LPPPPT) and the Low Point Pump Pit Sludge Tank (LPPPST), and went into detail the whole DWPF processes. This report provides discussion of each of the areas and processes of the DWPF in terms of potential nuclear safety issues and nuclear criticality concerns.
Date: May 10, 1993
Creator: Ha, B. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Rheology of Savannah River site tank 42 and tank 51 HLW radioactive sludges

Description: Knowledge of the rheology of the radioactive sludge slurries at the Savannah River Site (SRS) is necessary in order to ensure that they can be retrieved from waste tanks and processed for final disposal. The high activity radioactive wastes stored as caustic slurries at SRS result from the neutralization of acid waste generated from production of nuclear defense materials. During storage, the wastes separate into a supernate layer and a sludge layer. In the Defense Waste Processing Facility (DWPF) at SRS, the radionuclides from the sludge and supernate will be immobilized into borosilicate glass for long term storage and eventual disposal. Before transferring the waste from a storage tank to the DWPF, a portion of the aluminum in the waste sludge will be dissolved and the sludge will be extensively washed to remove sodium. Tank 51 and Tank 42 radioactive sludges represent the first batch of HLW sludge to be processed in the DWPF. This paper presents results of rheology measurements of Tank 51 and Tank 42 at various solids concentrations. The rheologies of Tank 51 and Tank 42 radioactive slurries were measured remotely in the Shielded Cells Operations (SCO) at the Savannah River Technology Center (SRTC) using a modified Haake Rotovisco RV-12 with an M150 measuring drive unit and TI sensor system. Rheological properties of the Tank 51 and Tank 42 radioactive sludges were measured as a function of weight percent solids. The weight percent solids of Tank 42 sludge was 27, as received. Tank 51 sludge had already been washed. The weight percent solids were adjusted by dilution with water or by concentration through drying. At 12, 15, and 18 weight percent solids, the yield stresses of Tank 51 sludge were 5, 11, and 14 dynes/cm2, respectively. The apparent viscosities were 6, 10, and 12 centipoises at 300 ...
Date: January 19, 1996
Creator: Ha, B.C. & Bibler, N.E.
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Rheology of Savannah River Site Tank 42 radioactive sludges. Revision 1

Description: Knowledge of the rheology of the radioactive sludge slurries at the Savannah River Site (SRS) is necessary in order to ensure that they can be retrieved from waste tanks and processed for final disposal. At Savannah River Site (SRS), Tank 42 sludge represents one of the first HLW radioactive sludges to be vitrified in the Defense Waste Processing Facility (DWPF). The rheological properties of unwashed Tank 42 sludge slurries at various solids concentrations were measured remotely in the Shielded Cells at the Savannah River Technology Center (SRTC) using a modified Haake Rotovisco viscometer. Rheological properties of Tank 42 radioactive sludge were measured as a function of weight percent total solids to ensure that the first DWPF radioactive sludge batch can be pumped and processed in the DWPF with the current design bases. The yield stress and consistency of the sludge slurries were determined by assuming a Bingham plastic fluid model.
Date: December 31, 1995
Creator: Ha, B.C. & Bibler, N.E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Criticality assessment of initial operations at the Defense Waste Processing Facility

Description: At the Savannah River Site (SRS), high level radioactive wastes will be immobilized into borosilicate glass for long term storage and eventual disposal. Since the waste feed streams contain uranium and plutonium, the Defense Waste Processing Facility (DWPF) process has been evaluated to ensure that a subcritical condition is maintained. It was determined that the risk of nuclear criticality in the DWPF during initial, sludge-only operations is minimal due to the dilute concentration of fissile material in the sludge combined with excess neutron absorbers.
Date: December 31, 1993
Creator: Ha, B. C. & Williamson, T. G.
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Partner: UNT Libraries Government Documents Department

Vitrification of Three Low-Activity Radioactive Waste Streams from Hanford

Description: As part of a demonstration for British Nuclear Fuels Limited, Incorporated (BNFL), the Immobilization Technology Section (ITS) of the Savannah River Technology Center (SRTC) has produced and characterized three low-activity waste (LAW) glasses from Hanford radioactive waste samples. The three LAW glasses were produced from radioactive supernate samples that had been treated by the Waste Processing Technology Section (WPTS) at SRTC to remove most of the radionuclides. These three glasses were produced by mixing the waste streams with between four and nine glass-forming chemicals in platinum/gold crucibles and heating the mixture to between 1120 and 1150 degrees C. Compositions of the resulting glass waste forms were close to the target compositions. Low concentrations of radionuclides in the LAW feed streams and, therefore, in the glass waste forms supported WPTS conclusions that pretreatment had been successful. No crystals were detected in the LAW glasses. In addition, all glass waste forms passed the leach tests that were performed. These included a 20 degrees C Product Consistency Test (PCT) and a modified version of the United States Environmental Protection Agency Toxicity Characteristic Leaching Procedure (TCLP).
Date: September 1, 1998
Creator: Ferrara, D.M.; Crawford, C.L.; Ha, B.C. & Bibler, N.E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

Criticality assessment of the Defense Waste Processing Facility

Description: Assessment of nuclear criticality potential of the S-Area Defense Waste Processing Facility (DWPF) is required to ensure the safe processing of radioactive waste for final disposal. At the Savannah River Site (SRS), high-level radioactive wastes are stored as caustic slurries. During storage, the wastes separate into a supernate layer and a sludge layer. The radionuclides from the sludge and supernate will be immobilized into borosilicate glass for storage and eventual disposal. The DWPF will initially immobilize sludge only, with simulated non-radioactive Precipitate Hydrolysis Aqueous (PHA) product. This paper demonstrates that criticality poses only a negligible risk in the DWPF process because of the characteristics of the waste and the DWPF process. The waste contains low concentration of fissile material and many elements which act as neutron poisons. Also, the DWPF process chemistry does not affect separation and accumulation of fissile materials. Experiments showed that DWPF can process all the high-level radioactive wastes currently stored at SRS with negligible criticality risk under normal and abnormal/process upset operation.
Date: August 1, 1996
Creator: Ha, B.C.; Williamson, T.G.; Clemmons, J.S. & Chandler, M.C.
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Partner: UNT Libraries Government Documents Department

Production of a High-Level Waste Glass from Hanford Waste Samples

Description: The HLW glass was produced from a HLW sludge slurry (Envelope D Waste), eluate waste streams containing high levels of Cs-137 and Tc-99, solids containing both Sr-90 and transuranics (TRU), and glass-forming chemicals. The eluates and Sr-90/TRU solids were obtained from ion-exchange and precipitation pretreatments, respectively, of other Hanford supernate samples (Envelopes A, B and C Waste). The glass was vitrified by mixing the different waste streams with glass-forming chemicals in platinum/gold crucibles and heating the mixture to 1150 degree C. Resulting glass analyses indicated that the HLW glass waste form composition was close to the target composition. The targeted waste loading of Envelope D sludge solids in the HLW glass was 30.7 wt percent, exclusive of Na and Si oxides. Condensate samples from the off-gas condenser and off-gas dry-ice trap indicated that very little of the radionuclides were volatilized during vitrification. Microstructure analysis of the HLW glass using Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Analysis (EDAX) showed what appeared to be iron spinel in the HLW glass. Further X-Ray Diffraction (XRD) analysis confirmed the presence of nickel spinel trevorite (NiFe2O4). These crystals did not degrade the leaching characteristics of the glass. The HLW glass waste form passed leach tests that included a standard 90 degree C Product Consistency Test (PCT) and a modified version of the United States Environmental Protection Agency Toxicity Characteristic Leaching Procedure (TCLP).
Date: September 1998
Creator: Crawford, C. L.; Farrara, D. M.; Ha, B. C. & Bibler, N. E.
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Partner: UNT Libraries Government Documents Department

Rheology of Savannah River site tank 42 HLW radioactive sludge

Description: Knowledge of the rheology of the radioactive sludge slurries at the Savannah River Site is necessary in order to ensure that they can be retrieved from waste tanks and processed for final disposal. At Savannah River Site, Tank 42 sludge represents on of the first HLW radioactive sludges to be vitrified in the Defense Waste Processing Facility. The rheological properties of unwashed Tank 42 sludge slurries at various solids concentrations were measured remotely in the Shielded Cells at the Savannah River Technology Center using a modified Haake Rotovisco viscometer.
Date: November 5, 1997
Creator: Ha, B.C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Vitrification of Three Low-Activity Radioactive Waste Streams from Hanford

Description: The Savannah River Technology Center (SRTC) used radioactive waste samples from Hanford to demonstrate a process being considered by British Nuclear Fuels Limited, Incorporated (BNFL) for immobilization of this waste. The paper being outlined in this summary will describe vitrification of the low-activity waste (LAW) streams resulting when three radioactive supernate samples were treated to remove the major radionuclides. Characterization of the resulting glass waste form showed that it met waste loading, durability, and leach resistance requirements set by the Department of Energy (DOE).
Date: July 1, 1998
Creator: Ferrara, D.; Crawford, C.L.; Ha, B.C. & Bibler, N.E.
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Partner: UNT Libraries Government Documents Department

Hydrogen production during processing of radioactive sludge containing noble metals

Description: Hydrogen was produced when radioactive sludge from Savannah River Site radioactive waste containing noble metals was reacted with formic acid. This will occur in a process tank in the Defense Waste Facility at SRS when waste is vitrified. Radioactive sludges from four tanks were tested in a lab-scale apparatus. Maximum hydrogen generation rates varied from 5 {times}10{sup {minus}7} g H{sub 2}/hr/g of sludge from the least reactive sludge (from Waste Tank 51) to 2 {times}10{sup {minus}4} g H{sub 2}/hr/g of sludge from the most reactive sludge (from Waste Tank 11). The time required for the hydrogen generation to reach a maximum varied from 4.1 to 25 hours. In addition to hydrogen, carbon dioxide and nitrous oxide were produced and the pH of the reaction slurry increased. In all cases, the carbon dioxide and nitrous oxide were generated before the hydrogen. The results are in agreement with large-scale studies using simulated sludges.
Date: January 1, 1992
Creator: Ha, B.C.; Ferrara, D.M. & Bibler, N.E.
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Partner: UNT Libraries Government Documents Department

Radioactive demonstration of the late wash'' Precipitate Hydrolysis Process

Description: This report presents results of the radioactive demonstration of the DWPF Precipitate Hydrolysis Process as it would occur in the late wash'' flowsheet in the absence of hydroxylamine nitrate. Radioactive precipitate containing Cs-137 from the April, 1983, in-tank precipitation demonstration in Tank 48 was used for these tests.
Date: June 30, 1992
Creator: Bibler, N.E.; Ferrara, D.M. & Ha, B.C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Radioactive demonstration of the ``late wash`` Precipitate Hydrolysis Process

Description: This report presents results of the radioactive demonstration of the DWPF Precipitate Hydrolysis Process as it would occur in the ``late wash`` flowsheet in the absence of hydroxylamine nitrate. Radioactive precipitate containing Cs-137 from the April, 1983, in-tank precipitation demonstration in Tank 48 was used for these tests.
Date: June 30, 1992
Creator: Bibler, N. E.; Ferrara, D. M. & Ha, B. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Decomposition of tetraphenylborate precipitates used to isolate Cs-137 from Savannah River Site high-level waste

Description: This paper presents results of the radioactive demonstration of the Precipitate Hydrolysis Process (PHP) that will be performed in the Defense Waste Processing Facility (DWPF) at the Savannah River Site. The PHP destroys the tetraphenylborate precipitate that is used at SRS to isolate Cs-137 from caustic High-Level Waste (HLW) supernates. This process is necessary to decrease the amount of organic compounds going to the melter in the DWPF. Actual radioactive precipitate containing Cs-137 was used for this demonstration.
Date: March 1, 1993
Creator: Ferrara, D. M.; Bibler, N. E. & Ha, B. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

Hydrogen production during processing of radioactive sludge containing noble metals

Description: Hydrogen was produced when radioactive sludge from Savannah River Site radioactive waste containing noble metals was reacted with formic acid. This will occur in a process tank in the Defense Waste Facility at SRS when waste is vitrified. Radioactive sludges from four tanks were tested in a lab-scale apparatus. Maximum hydrogen generation rates varied from 5 {times}10{sup {minus}7} g H{sub 2}/hr/g of sludge from the least reactive sludge (from Waste Tank 51) to 2 {times}10{sup {minus}4} g H{sub 2}/hr/g of sludge from the most reactive sludge (from Waste Tank 11). The time required for the hydrogen generation to reach a maximum varied from 4.1 to 25 hours. In addition to hydrogen, carbon dioxide and nitrous oxide were produced and the pH of the reaction slurry increased. In all cases, the carbon dioxide and nitrous oxide were generated before the hydrogen. The results are in agreement with large-scale studies using simulated sludges.
Date: September 1, 1992
Creator: Ha, B. C.; Ferrara, D. M. & Bibler, N. E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

Off-Gas Analysis During the Vitrification of Hanford Radioactive Waste Samples

Description: This paper describes the off-gas analysis of samples collected during the radioactive vitrification experiments. Production and characterization of the Hanford waste-containing LAW and HAW glasses are presented in related reports from this conference.
Date: March 1, 1998
Creator: Ha, B.C.; Ferrara, D.M.; Crawford, C.L.; Choi, A.S. & Bibler, N.E.
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Partner: UNT Libraries Government Documents Department

Development of a Nitric/Formic Acid process to reduce hydrogen emissions during sludge treatment in the DWPF

Description: A new Nitric/Formic Acid (N/FA) flowsheet was developed at the Savannah River Technology Center (SRTC) for use in the Chemical Processing Cell (CPC) of the Defense Waste Processing Facility (DWPF). The flowsheet was successfully demonstrated with simulated sludge using a 2 L bench-scale experimental system and a one-fifth scale (4000 L) pilot facility, and with actual radioactive waste using a 0.1 L apparatus in one of the SRTC shielded cells. Overall, the new N/FA flowsheet compared to the original formic add flowsheet reduced the peak H{sub 2} generation rate by more than a factor of two and resulted in a more gradual rise in the H{sub 2} evolution. Therefore, implementation of the new N/FA flowsheet in the DWPF CPC would result in an increased margin of safety and possibly a reduction in the scope and cost of modifying the DWPF CPC vessel vent system. Also, the new N/FA flowsheet would be compatible with Tank Farm processes and other DWPF flowsheets, and with the implementation of the new Late Wash flowsheet in the DWPF, it would be key to maintaining a proper redox balance of the melter feed.
Date: September 1, 1993
Creator: Hsu, C. W.; Ferrara, D. M.; Bibler, N. E.; Ha, B. C. & Ritter, J. A.
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Analytical study plan: Shielded Cells batch 1 campaign; Revision 1

Description: Radioactive operations in the Defense Waste Processing Facility (DWPF) will require that the Savannah River Technology Center (SRTC) perform analyses and special studies with actual Savannah River Site (SRS) high-level waste sludge. SRS Tank 42 and Tank 51 will comprise the first batch of sludge to be processed in the DWPF. Approximately 25 liters of sludge from each of these tanks will be characterized and processed in the Shielded Cells of SRTC. During the campaign, processes will include sludge characterization, sludge washing, rheology determination, mixing, hydrogen evolution, feed preparation, and vitrification of the waste. To complete the campaign, the glass will be characterized to determine its durability and crystallinity. This document describes the types of samples that will be produced, the sampling schedule and analyses required, and the methods for sample and analytical control.
Date: October 4, 1993
Creator: Bibler, N. E.; Ha, B. C.; Hay, M. S.; Ferrara, D. M. & Andrews, M. K.
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Partner: UNT Libraries Government Documents Department

Research and development task plan: Shielded Cells Batch 1 campaign. Revision 2

Description: The primary objectives of this task are to characterize the sludge, to identify any unexpected processing problems, and to demonstrate the ability to make an acceptable glass product. Another objective is to determine the amount of washing that the sludge from Tank 42 requires. The 500 ml glass Sludge Receipt and Adjustment Tank (SRAT) and the 100 L stainless steel SRAT have already been used in the Shielded Cells to demonstrate the process using samples from other tanks. The melter and off-gas system have also been used in the Shielded Cells to vitrify sludge from Tanks 8 & 12 and from Tank 51.
Date: October 8, 1993
Creator: Andrews, M. K.; Bibler, N. E.; Ferrara, D. M.; Ha, B. C. & Hay, M. S.
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Partner: UNT Libraries Government Documents Department

Minutes: SRL Criticality and Accountability Review Committee. [Savannah River Laboratory (SRL)]

Description: Various aspects safety procedures concerning the handling of fissile materials at Savannah river plant are presented in these (12-16-91) meeting minutes. Criticality control procedures, inconsistencies in mass limit forms, and nuclear incident monitors, etc. are briefly discussed. (GHH)
Date: January 2, 1992
Creator: Gerrard, P.B.; Ha, B.C.; Jolly, L.; Key, F.; Rudisill, T.S.; Trumble, E.F. et al.
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Partner: UNT Libraries Government Documents Department