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Development of Chemical Treatment Alternatives for Tetraphenylborate Destruction in Tank 48H

Description: This study assessed chemical treatment options for decomposing the tetraphenylborate in High Level Waste (HLW) Tank 48H. Tank 48H, located at the Savannah River Site in Aiken, SC, contains approximately one million liters of HLW. The tetraphenylborate slurry represents legacy material from commissioning of an In Tank Precipitation process to separate radioactive cesium and actinides from the nonradioactive chemicals. During early operations, the process encountered an unplanned chemical reaction that catalytically decomposed the excess tetraphenylborate producing benzene. Subsequent research indicated that personnel could not control the operations within the existing equipment to both meet the desired treatment rate for the waste and maintain the benzene concentration within allowable concentrations. Since then, the Department of Energy selected an alternate treatment process for handling high-level waste at the site. However, the site must destroy the tetraphenylborate before returning the tank to HLW service. The research focuses on identifying treatments to decompose tetraphenylborate to the maximum extent feasible, with a preference for decomposition methods that produce carbon dioxide rather than benzene. A number of experiments examined whether the use of oxidants, catalysts or acids proved effective in decomposing the tetraphenylborate. Additional experiments developed an understanding of the solid, liquid and gas decomposition products.
Date: March 11, 2003
Creator: Lambert, D.P.
Partner: UNT Libraries Government Documents Department

Determining the Cause for Low Flowrates during Am/Cm Simulant Testing in F-Area

Description: 30,000 gallons of Americium/Curium (Am/Cm) slurry was transferred from F-Canyon to Tank 51H over an 18 hour period. This was the first continuous transfer of waste from F-Canyon to a waste tank. Prior to the successful Am/Cm transfer, the facility had experienced difficulties in transferring simulated solutions. A team of personnel from several divisions worked in well-coordinated fashion to determine a cost effective means to identify and mitigate the obstacles to the transfer. The team successfully diagnosed the causes of the problem, replicated the observed behavior in laboratory tests and computer modeling, and recommended controls and changes to facility operations. A successful simulant transfer demonstrated readiness for the Am/Cm transfer. This report summarizes the results of the investigation to determine the cause for the poor flow rate experienced during simulant testing in F-Area. Flow rates as low as 3 gallons per minute (gpm) occurred at the end of the transfer. This report includes an explanation for the low flow rate and recommends controls to prevent the reoccurrence. We recommend the following controls to prevent the reoccurrence of slow flows. 1. Control the temperature of the contents of the simulant and real waste storage tanks near ambient during preparation and storage. Temperature control will minimize the inadvertent evaporation of the slurry and minimize any negative impacts of a high temperature during precipitation and storage of the slurry. 2. Avoid any evolution that can inadvertently concentrate the solutions. Well mixed storage tanks and the proper jet or pump operation are necessary to ensure a uniform slurry transfer and avoid concentrating a heel in Tank 13.3. 3. Minimize the air purge rate in the storage tanks after preparation of the simulant and actual waste. The purge leads to slow evaporation of the slurry as well as addition of carbonates, from carbon dioxide sorption. ...
Date: September 8, 2003
Creator: Lambert, D.P.
Partner: UNT Libraries Government Documents Department

Ventilation criteria for IDMS facility

Description: Both Facility Evaluation Board (FEB) reviews of the Integrated DWPF Melter System (IDMS) have identified the inconsistency of the current IDMS Process Hazards Review (PHR) versus actual IDMS practice as regards the criteria to contain air borne pollutants that may be present in the Process Room (e.g. benzene and mercury). The PHR states that a 1.0 in. wc pressure differential be maintained between the IDMS Process Room and Building 672-T. In addition, the PHR further specifies that the linear velocity through openings into the Process Room (e.g. open doors) be equal to or greater than 150 fpm. Finally, the PHR recommended that mercury vapor and benzene monitors be installed in the Process Room ventilation exhaust to alert personnel to the presence of vapors of benzene and/or mercury before entering the Process Room. This report summarizes the results of reassessment of these criteria and the specific recommendation for permanent installation of mercury and benzene vapor monitors in the vapor exhaust of the Process Room.
Date: July 3, 1996
Creator: Lambert, D.P.
Partner: UNT Libraries Government Documents Department

Ammonia scrubber testing during IDMS SRAT and SME processing. Revision 1

Description: This report summarizes results of the Integrated DWPF (Defense Waste Processing Facility) Melter System (IDMS) ammonia scrubber testing during the PX-7 run (the 7th IDMS run with a Purex type sludge). Operation of the ammonia scrubber during IDMS Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator (SME) processing has been completed. The ammonia scrubber was successful in removing ammonia from the vapor stream to achieve NH3 concentrations far below the 10 ppM vapor exist design basis during SRAT processing. However, during SME processing, vapor NH3 concentrations as high as 450 ppM were measured exiting the scrubber. Problems during the SRAT and SME testing were vapor bypassing the scrubber and inefficient scrubbing of the ammonia at the end of the SME cycle (50% removal efficiency; 99.9% is design basis efficiency).
Date: April 28, 1995
Creator: Lambert, D.P.
Partner: UNT Libraries Government Documents Department

Cylinder supplied ammonia scrubber testing in IDMS

Description: This report summarizes the results of the off-line testing the Integrated DWPF Melter System (IDMS) ammonia scrubbers using ammonia supplied from cylinders. Three additional tests with ammonia are planned to verify the data collected during off-line testing. Operation of the ammonia scrubber during IDMS SRAT and SME processing will be completed during the next IDMS run. The Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator (SME) scrubbers were successful in removing ammonia from the vapor stream to achieve ammonia vapor concentrations far below the 10 ppM vapor exit design basis. In most of the tests, the ammonia concentration in the vapor exit was lower than the detection limit of the analyzers so results are generally reported as <0.05 parts per million (ppM). During SRAT scrubber testing, the ammonia concentration was no higher than 2 ppM and during SME testing the ammonia concentration was no higher than 0.05 m.
Date: August 31, 1994
Creator: Lambert, D.P.
Partner: UNT Libraries Government Documents Department

Illinois Institute of Technology Report: IITB52 Antifoamer for Alternative Salt Processes

Description: The attached report is a summary of the work performed by Dr. Darsh Wasan, Dr. Alex Nikolov, and their researchers at the Illinois Institute of Technology (IIT) during FY01. IIT developed the IITB52 antifoam for SRTC in FY00 to minimize the foam produced during precipitation, washing and concentration of cesium and potassium tetraphenyl borate precipitate. The IITB52 antifoam has been very successful during continuous processing (prototypical of plant operation). However, there were several key issues where SRTC needed the experience and knowledge of IIT to resolve. As a result a subcontract was set up with Dr. Wasan and Dr. Alex Nikolov during FY01. This subcontract requested IIT to perform the basic research necessary to understand the foaming mechanism and explain the effectiveness of the IITB52 antifoam agent in the Small Tank Tetraphenylborate Process (STTP).
Date: June 27, 2001
Creator: Lambert, D.P.
Partner: UNT Libraries Government Documents Department

Melt Rate Improvement for DWPF MB3: Summary and Recommendations

Description: The objective for this task is to understand and apply the control of glass batch chemistry (frit composition) and/or changes in chemical processing strategies to improve the overall melting process for Macrobatch 3 (MB3) (Defense Waste Processing Facility (DWPF) sludge-only processing). For melt rate limited systems, a small increase in melting efficiency translates into substantial savings by reducing operational costs without compromising the quality of the final waste product. This report summarizes the key information collected during the FY01 melt-rate testing completed to support the conclusion that switching from Frit 200, the frit currently used to prepare all the glass produced in radioactive processing, to Frit 320 should improve the melt rate during processing of DWPF MB3 sludge (Note: MB3 is referred to as Sludge Batch 2 in the High-Level Waste System Plan). The report also includes recommendations that should be addressed prior to implementation of the new frit and future research that should be completed to further improve melt rate. No analysis has been completed to determine if Frit 320 can be used in processing of other sludge macrobatches. The testing in this report is based on dried-slurry testing of a MB3 melter feed prepared from nonradioactive simulants. Additional testing, particularly with a melter feed slurry and actual waste, would be required before implementing the new frit in DWPF, and a variability study would also be necessary. The work to date, at most, provides relative data until actual melter data can be obtained and compared.
Date: July 11, 2001
Creator: Lambert, D. P.
Partner: UNT Libraries Government Documents Department

Tank 42 sludge-only process development for the Defense Waste Processing Facility (DWPF)

Description: Defense Waste Processing Facility (DWPF) requested the development of a sludge-only process for Tank 42 sludge since at the current processing rate, the Tank 51 sludge has been projected to be depleted as early as August 1998. Testing was completed using a non-radioactive Tank 42 sludge simulant. The testing was completed under a range of operating conditions, including worst case conditions, to develop the processing conditions for radioactive Tank 42 sludge. The existing Tank 51 sludge-only process is adequate with the exception that 10 percent additional acid is recommended during sludge receipt and adjustment tank (SRAT) processing to ensure adequate destruction of nitrite during the SRAT cycle.
Date: March 22, 2000
Creator: Lambert, D.P.
Partner: UNT Libraries Government Documents Department

Tank 50H Flammability Calculations

Description: This report presents the results form the Phase 1 testing. Phase 1 was designed to determine the tetraphenylborate decomposition rate of the 4PB present in Tank 50H if Tank 23H or Inhibited Water is added to the tank.
Date: May 26, 2003
Creator: Lambert, D.P.
Partner: UNT Libraries Government Documents Department

Downstream Impacts of Tank 48H In-tank and Out-of-tank Processing Alternatives

Description: This document discusses a number of possible impacts that an in-tank or out-of-tank process may have on downstream processing facilities. The analysis is part of a task to develop processes to destroy tetraphenylborate using Fenton Chemistry (metal catalyst plus hydrogen peroxide). Two processes being evaluated are funded by a grant from DOE's National Energy Technology Center. The first is an in-tank process, where the tetraphenylborate is destroyed by decreasing the pH, increasing the temperature and adding a catalyst and hydrogen peroxide as required. After the TPB is destroyed, sodium hydroxide and sodium nitrite are added to the tank to return the tank to conditions that minimize corrosion. The resulting slurry is stored in a HLW tank, likely concentrated in the HLW evaporators, and later will be fed to the Salt Waste Processing Facility. The second process is an out-of-tank Fenton process. This process produces two streams, a high cesium stream that feeds to DWPF and a low cesium feed that returns to a HLW tank with the DWPF recycle. The recycle stream may be evaporated in the HLW evaporators, and will later be fed to the Saltstone Facility or the Actinide Removal Process. An additional two processes being evaluated are in-tank processes. In the first, thermal hydrolysis, the TPB is destroyed by decreasing the pH and increasing the temperature. In the second process, thermal hydrolysis, the TPB is destroyed in by decreasing the pH, adding a catalyst, and increasing the temperature. After the TPB is destroyed, sodium hydroxide and sodium nitrite are added to the tank to return the tank to conditions that minimize corrosion. The resulting slurry is stored in a HLW tank, will likely be concentrated in the HLW evaporators and later will be fed to the Salt Waste Processing Facility. This evaluation is designed to identify possible ...
Date: December 22, 2003
Creator: Lambert, D.P.
Partner: UNT Libraries Government Documents Department

Feed Preparation for Source of Alkali Melt Rate Tests

Description: The purpose of the Source of Alkali testing was to prepare feed for melt rate testing in order to determine the maximum melt-rate for a series of batches where the alkali was increased from 0% Na{sub 2}O in the frit (low washed sludge) to 16% Na{sub 2}O in the frit (highly washed sludge). This document summarizes the feed preparation for the Source of Alkali melt rate testing. The Source of Alkali melt rate results will be issued in a separate report. Five batches of Sludge Receipt and Adjustment Tank (SRAT) product and four batches of Slurry Mix Evaporator (SME) product were produced to support Source of Alkali (SOA) melt rate testing. Sludge Batch 3 (SB3) simulant and frit 418 were used as targets for the 8% Na{sub 2}O baseline run. For the other four cases (0% Na{sub 2}O, 4% Na{sub 2}O, 12% Na{sub 2}O, and 16% Na{sub 2}O in frit), special sludge and frit preparations were necessary. The sludge preparations mimicked washing of the SB3 baseline composition, while frit adjustments consisted of increasing or decreasing Na and then re-normalizing the remaining frit components. For all batches, the target glass compositions were identical. The five SRAT products were prepared for testing in the dry fed melt-rate furnace and the four SME products were prepared for the Slurry-fed Melt-Rate Furnace (SMRF). At the same time, the impacts of washing on a baseline composition from a Chemical Process Cell (CPC) perspective could also be investigated. Five process simulations (0% Na{sub 2}O in frit, 4% Na{sub 2}O in frit, 8% Na{sub 2}O in frit or baseline, 12% Na{sub 2}O in frit, and 16% Na{sub 2}O in frit) were completed in three identical 4-L apparatus to produce the five SRAT products. The SRAT products were later dried and combined with the complementary frits to produce ...
Date: February 26, 2005
Creator: Stone, M. E. & Lambert, D. P.
Partner: UNT Libraries Government Documents Department

Experimental study of SRAT/SME foaming by Illinois Institute of Technology

Description: This report summarizes the results of experiments performed by IIT in an effort to understand the fundamental science involved in the stable foam formation in the Defense Waste Processing Facility`s (DWPF`s) Chemical Processing Cell (CPC). The results of this testing will be confirmed in an experimental apparatus designed to be prototypic of DWPF CPC processing.
Date: November 10, 1997
Creator: Lambert, D.P. & Wasan, D.T.
Partner: UNT Libraries Government Documents Department

Precipitate hydrolysis experimental facility (PHEF) Run 66 And 67, Final report

Description: During the period from late June to early September of this year, approximately 1,600 gallons of precipitate feed stored in the Precipitate Hold Tank (PHT) at PHEF decomposed. This decomposition took place during a two month storage period of the Tetraphenyl borate (TPB) precipitate under a CO{sub 2} blanket. The visual inspection of the tank revealed that a very small amount of TPB solids were left and that there were approximately 100 to 110 gals of benzene/high boilers present in the tank. The resultant decomposition products in the PHT consist of an organic and aqueous phase containing a small quantity of unreacted solids. A path forward was developed to understand TPB decomposition and to determine if the material remaining in the PHT could be processed without adverse effects to the process or equipment. A small scale hydrolysis run with the remaining PHT material was made by Process Technology Development Group of DWPT at TNX. It was determined from small scale runs and an extensive analysis of the PHT material that the decomposed material was safe to run at PHEF without adversely affecting the process or equipment. The PHT volume was 1,592 gallons at the time of decomposition. Two runs (66 and 67) were performed to process the decomposed feed. The main objective of these runs was to process the decomposed precipitate from the PHT. In both the runs copper nitrate was used as the catalyst. Because of the decomposition, the effectiveness of the copper nitrate in catalyzing the destruction of TPB could not be completed. The significant findings of Run 66 are: (1) after 5 hours of aqueous boil, the aqueous product had a Diphenylamine (DPA) concentration of 31 mg/L and the Biphenyl concentration of 8 mg/L. At these concentrations, the high boiling organic mass in the aqueous product included ...
Date: February 11, 2000
Creator: Shah, H. B. & Lambert, D. P.
Partner: UNT Libraries Government Documents Department

Impact of Alkali Source on Vitrification of SRS High Level Waste

Description: The Defense Waste Processing Facility (DWPF) Savannah River Site is currently immobilizing high level nuclear waste sludge by vitrification in borosilicate glass. The processing strategy involves blending a large batch of sludge into a feed tank, washing the sludge to reduce the amount of soluble species, then processing the large ''sludge batch'' through the DWPF. Each sludge batch is tested by the Savannah River National Laboratory (SRNL) using simulants and tests with samples of the radioactive waste to ''qualify'' the batch prior to processing in the DWPF. The DWPF pretreats the sludge by first acidifying the sludge with nitric and formic acid. The ratio of nitric to formic acid is adjusted as required to target a final glass composition that is slightly reducing (the target is for {approx}20% of the iron to have a valence of two in the glass). The formic acid reduces the mercury in the feed to elemental mercury which is steam stripped from the feed. After a concentration step, the glass former (glass frit) is added as a 50 wt% slurry and the batch is concentrated to approximately 50 wt% solids. The feed slurry is then fed to a joule heated melter maintained at 1150 C. The glass must meet both processing (e.g., viscosity and liquidus temperature) and product performance (e.g., durability) constraints The alkali content of the final waste glass is a critical parameter that affects key glass properties (such as durability) as well as the processing characteristics of the waste sludge during the pretreatment and vitrification processes. Increasing the alkali content of the glass has been shown to improve the production rate of the DWPF, but the total alkali in the final glass is limited by constraints on glass durability and viscosity. Two sources of alkali contribute to the final alkali content of the ...
Date: September 8, 2005
Creator: LAMBERT, D. P.; MILLER, D. H.; PEELER, D. K.; SMITH, M. E. & STONE, M. E.
Partner: UNT Libraries Government Documents Department

Development Of Ion Chromatography Methods To Support Testing Of The Glycolic Acid Reductant Flowsheet In The Defense Waste Processing Facility

Description: Ion Chromatography (IC) is the principal analytical method used to support studies of Sludge Reciept and Adjustment Tank (SRAT) chemistry at DWPF. A series of prior analytical ''Round Robin'' (RR) studies included both supernate and sludge samples from SRAT simulant, previously reported as memos, are tabulated in this report.2,3 From these studies it was determined to standardize IC column size to 4 mm diameter, eliminating the capillary column from use. As a follow on test, the DWPF laboratory, the PSAL laboratory, and the AD laboratory participated in the current analytical RR to determine a suite of anions in SRAT simulant by IC, results also are tabulated in this report. The particular goal was to confirm the laboratories ability to measure and quantitate glycolate ion. The target was + or - 20% inter-lab agreement of the analyte averages for the RR. Each of the three laboratories analyzed a batch of 12 samples. For each laboratory, the percent relative standard deviation (%RSD) of the averages on nitrate, glycolate, and oxalate, was 10% or less. The three laboratories all met the goal of 20% relative agreement for nitrate and glycolate. For oxalate, the PSAL laboratory reported an average value that was 20% higher than the average values reported by the DWPF laboratory and the AD laboratory. Because of this wider window of agreement, it was concluded to continue the practice of an additional acid digestion for total oxalate measurement. It should also be noted that large amounts of glycolate in the SRAT samples will have an impact on detection limits of near eluting peaks, namely Fluoride and Formate. A suite of scoping experiments are presented in the report to identify and isolate other potential interlaboratory disceprancies. Specific ion chromatography inter-laboratory method conditions and differences are tabulated. Most differences were minor but there are ...
Date: October 1, 2013
Creator: Wiedenman, B. J.; White, T. L.; Mahannah, R. N.; Best, D. R.; Stone, M. E.; Click, D. R. et al.
Partner: UNT Libraries Government Documents Department

Organics Characterization Of DWPF Alternative Reductant Simulants, Glycolic Acid, And Antifoam 747

Description: The present study examines the fate of glycolic acid and other organics added in the Chemical Processing Cell (CPC) of the Defense Waste Processing Facility (DWPF) as part of the glycolic alternate flowsheet. Adoption of this flowsheet is expected to provide certain benefits in terms of a reduction in the processing time, a decrease in hydrogen generation, simplification of chemical storage and handling issues, and an improvement in the processing characteristics of the waste stream including an increase in the amount of nitrate allowed in the CPC process. Understanding the fate of organics in this flowsheet is imperative because tank farm waste processed in the CPC is eventually immobilized by vitrification; thus, the type and amount of organics present in the melter feed may affect optimal melt processing and the quality of the final glass product as well as alter flammability calculations on the DWPF melter off gas. To evaluate the fate of the organic compounds added as the part of the glycolic flowsheet, mainly glycolic acid and antifoam 747, samples of simulated waste that was processed using the DWPF CPC protocol for tank farm sludge feed were generated and analyzed for organic compounds using a variety of analytical techniques at the Savannah River National Laboratory (SRNL). These techniques included Ion Chromatography (IC), Gas Chromatography-Mass Spectrometry (GC-MS), Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES), and Nuclear Magnetic Resonance (NMR) Spectroscopy. A set of samples were also sent to the Catholic University of America Vitreous State Laboratory (VSL) for analysis by NMR Spectroscopy at the University of Maryland, College Park. Analytical methods developed and executed at SRNL collectively showed that glycolic acid was the most prevalent organic compound in the supernatants of Slurry Mix Evaporator (SME) products examined. Furthermore, the studies suggested that commercially available glycolic acid contained minor amounts of impurities ...
Date: October 1, 2013
Creator: White, T. L.; Wiedenman, B. J.; Lambert, D. P.; Crump, S. L.; Fondeur, F. F.; Papathanassiu, A. E. et al.
Partner: UNT Libraries Government Documents Department