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Plutonium Speciation in Support of Oxidative-Leaching Demonstration Test

Description: Bechtel National, Inc. (BNI) is evaluating the plutonium speciation in caustic solutions that reasonably represent the process streams from the oxidative-leaching demonstration test. Battelle—Pacific Northwest Division (PNWD) was contracted to develop a spectrophotometric method to measure plutonium speciation at submicromolar (< 10-6 M) concentrations in alkaline solutions in the presence of chromate and carbonate. Data obtained from the testing will be used to identify the oxidation state of Pu(IV), Pu(V), and Pu(VI) species, which potentially could exist in caustic leachates. Work was initially conducted under contract number 24590-101-TSA-W000-00004 satisfying the needs defined in Appendix C of the Research and Technology Plan TSS A-219 to evaluate the speciation of chromium, plutonium, and manganese before and after oxidative leaching. In February 2007, the contract mechanism was switched to Pacific Northwest National Laboratory (PNNL) Operating Contract MOA: 24590-QL-HC9-WA49-00001.
Date: October 31, 2007
Creator: Sinkov, Sergey I.
Partner: UNT Libraries Government Documents Department

Warm Water Oxidation Verification - Scoping and Stirred Reactor Tests

Description: Scoping tests to evaluate the effects of agitation and pH adjustment on simulant sludge agglomeration and uranium metal oxidation at {approx}95 C were performed under Test Instructions(a,b) and as per sections 5.1 and 5.2 of this Test Plan prepared by AREVA. (c) The thermal testing occurred during the week of October 4-9, 2010. The results are reported here. For this testing, two uranium-containing simulant sludge types were evaluated: (1) a full uranium-containing K West (KW) container sludge simulant consisting of nine predominant sludge components; (2) a 50:50 uranium-mole basis mixture of uraninite [U(IV)] and metaschoepite [U(VI)]. This scoping study was conducted in support of the Sludge Treatment Project (STP) Phase 2 technology evaluation for the treatment and packaging of K-Basin sludge. The STP is managed by CH2M Hill Plateau Remediation Company (CHPRC) for the U.S. Department of Energy. Warm water ({approx}95 C) oxidation of sludge, followed by immobilization, has been proposed by AREVA and is one of the alternative flowsheets being considered to convert uranium metal to UO{sub 2} and eliminate H{sub 2} generation during final sludge disposition. Preliminary assessments of warm water oxidation have been conducted, and several issues have been identified that can best be evaluated through laboratory testing. The scoping evaluation documented here was specifically focused on the issue of the potential formation of high strength sludge agglomerates at the proposed 95 C process operating temperature. Prior hydrothermal tests conducted at 185 C produced significant physiochemical changes to genuine sludge, including the formation of monolithic concretions/agglomerates that exhibited shear strengths in excess of 100 kPa (Delegard et al. 2007).
Date: June 15, 2011
Creator: Braley, Jenifer C.; Sinkov, Sergey I.; Delegard, Calvin H. & Schmidt, Andrew J.
Partner: UNT Libraries Government Documents Department

Preparation and Characterization of Uranium Oxides in Support of the K Basin Sludge Treatment Project

Description: Uraninite (UO2) and metaschoepite (UO3·2H2O) are the uranium phases most frequently observed in K Basin sludge. Uraninite arises from the oxidation of uranium metal by anoxic water and metaschoepite arises from oxidation of uraninite by atmospheric or radiolytic oxygen. Studies of the oxidation of uraninite by oxygen to form metaschoepite were performed at 21°C and 50°C. A uranium oxide oxidation state characterization method based on spectrophotometry of the solution formed by dissolving aqueous slurries in phosphoric acid was developed to follow the extent of reaction. This method may be applied to determine uranium oxide oxidation state distribution in K Basin sludge. The uraninite produced by anoxic corrosion of uranium metal has exceedingly fine particle size (6 nm diameter), forms agglomerates, and has the formula UO2.004±0.007; i.e., is practically stoichiometric UO2. The metaschoepite particles are flatter and wider when prepared at 21°C than the particles prepared at 50°C. These particles are much smaller than the metaschoepite observed in prolonged exposure of actual K Basin sludge to warm moist oxidizing conditions. The uraninite produced by anoxic uranium metal corrosion and the metaschoepite produced by reaction of uraninite aqueous slurries with oxygen may be used in engineering and process development testing. A rapid alternative method to determine uranium metal concentrations in sludge also was identified.
Date: July 8, 2008
Creator: Sinkov, Sergey I.; Delegard, Calvin H. & Schmidt, Andrew J.
Partner: UNT Libraries Government Documents Department

Mitigation of Hydrogen Gas Generation from the Reaction of Uranium Metal with Water in K Basin Sludge and Sludge Waste Forms

Description: Prior laboratory testing identified sodium nitrate and nitrite to be the most promising agents to minimize hydrogen generation from uranium metal aqueous corrosion in Hanford Site K Basin sludge. Of the two, nitrate was determined to be better because of higher chemical capacity, lower toxicity, more reliable efficacy, and fewer side reactions than nitrite. The present lab tests were run to determine if nitrate’s beneficial effects to lower H2 generation in simulated and genuine sludge continued for simulated sludge mixed with agents to immobilize water to help meet the Waste Isolation Pilot Plant (WIPP) waste acceptance drainable liquid criterion. Tests were run at ~60°C, 80°C, and 95°C using near spherical high-purity uranium metal beads and simulated sludge to emulate uranium-rich KW containerized sludge currently residing in engineered containers KW-210 and KW-220. Immobilization agents tested were Portland cement (PC), a commercial blend of PC with sepiolite clay (Aquaset II H), granulated sepiolite clay (Aquaset II G), and sepiolite clay powder (Aquaset II). In all cases except tests with Aquaset II G, the simulated sludge was mixed intimately with the immobilization agent before testing commenced. For the granulated Aquaset II G clay was added to the top of the settled sludge/solution mixture according to manufacturer application directions. The gas volumes and compositions, uranium metal corrosion mass losses, and nitrite, ammonia, and hydroxide concentrations in the interstitial solutions were measured. Uranium metal corrosion rates were compared with rates forecast from the known uranium metal anoxic water corrosion rate law. The ratios of the forecast to the observed rates were calculated to find the corrosion rate attenuation factors. Hydrogen quantities also were measured and compared with quantities expected based on non-attenuated H2 generation at the full forecast anoxic corrosion rate to arrive at H2 attenuation factors. The uranium metal corrosion rates in water alone ...
Date: June 8, 2011
Creator: Sinkov, Sergey I.; Delegard, Calvin H. & Schmidt, Andrew J.
Partner: UNT Libraries Government Documents Department

Characteristics of STP Pre-2004 Archived KE Basin Sludge Samples Before and After Re-Jarring in the RPL - April 2012

Description: This report describes results of work performed in the Shielded Analytical Laboratory (SAL) at the Pacific Northwest National Laboratory’s (PNNL) Radiochemical Processing Laboratory (RPL) with archive K East (KE) Basin sludge samples obtained before the year 2004, with some of them composited and initially characterized five years ago (Delegard et al. 2011). The previously performed testing included the physical properties determinations for selected samples (settled and particle densities, water and solids concentrations), the pH, as well as identification of crystalline phases by X-ray diffractometry (XRD) for selected samples. Another objective of the previous characterization and testing campaign was to transfer some sludge composites and individual samples into new storage containers to overcome the embrittlement effect which develops in original glass containers as a result of extended exposure to high radiation fields and which increases probability of sample loss.
Date: September 28, 2012
Creator: Sinkov, Sergey I.; Delegard, Calvin H.; Schmidt, Andrew J. & Chenault, Jeffrey W.
Partner: UNT Libraries Government Documents Department

Separating the Minor Actinides Through Advances in Selective Coordination Chemistry

Description: This report describes work conducted at the Pacific Northwest National Laboratory (PNNL) in Fiscal Year (FY) 2012 under the auspices of the Sigma Team for Minor Actinide Separation, funded by the U.S. Department of Energy Office of Nuclear Energy. Researchers at PNNL and Argonne National Laboratory (ANL) are investigating a simplified solvent extraction system for providing a single-step process to separate the minor actinide elements from acidic high-level liquid waste (HLW), including separating the minor actinides from the lanthanide fission products.
Date: August 22, 2012
Creator: Lumetta, Gregg J.; Braley, Jenifer C.; Sinkov, Sergey I. & Carter, Jennifer C.
Partner: UNT Libraries Government Documents Department

Uranium Metal Analysis via Selective Dissolution

Description: Uranium metal, which is present in sludge held in the Hanford Site K West Basin, can create hazardous hydrogen atmospheres during sludge handling, immobilization, or subsequent transport and storage operations by its oxidation/corrosion in water. A thorough knowledge of the uranium metal concentration in sludge therefore is essential to successful sludge management and waste process design. The goal of this work was to establish a rapid routine analytical method to determine uranium metal concentrations as low as 0.03 wt% in sludge even in the presence of up to 1000-fold higher total uranium concentrations (i.e., up to 30 wt% and more uranium) for samples to be taken during the upcoming sludge characterization campaign and in future analyses for sludge handling and processing. This report describes the experiments and results obtained in developing the selective dissolution technique to determine uranium metal concentration in K Basin sludge.
Date: September 10, 2008
Creator: Delegard, Calvin H.; Sinkov, Sergey I.; Schmidt, Andrew J. & Chenault, Jeffrey W.
Partner: UNT Libraries Government Documents Department

Effects of Time, Heat, and Oxygen on K Basin Sludge Agglomeration, Strength, and Solids Volume

Description: Sludge disposition will be managed in two phases under the K Basin Sludge Treatment Project. The first phase is to retrieve the sludge that currently resides in engineered containers in the K West (KW) Basin pool at ~10 to 18°C. The second phase is to retrieve the sludge from interim storage in the sludge transport and storage containers (STSCs) and treat and package it in preparation for eventual shipment to the Waste Isolation Pilot Plant. The work described in this report was conducted to gain insight into how sludge may change during long-term containerized storage in the STSCs. To accelerate potential physical and chemical changes, the tests were performed at temperatures and oxygen partial pressures significantly greater than those expected in the T Plant canyon cells where the STSCs will be stored. Tests were conducted to determine the effects of 50°C oxygenated water exposure on settled quiescent uraninite (UO2) slurry and a full simulant of KW containerized sludge to determine the effects of oxygen and heat on the composition and mechanical properties of sludge. Shear-strength measurements by vane rheometry also were conducted for UO2 slurry, mixtures of UO2 and metaschoepite (UO3•2H2O), and for simulated KW containerized sludge. The results from these tests and related previous tests are compared to determine whether the settled solids in the K Basin sludge materials change in volume because of oxidation of UO2 by dissolved atmospheric oxygen to form metaschoepite. The test results also are compared to determine if heating or other factors alter sludge volumes and to determine the effects of sludge composition and settling times on sludge shear strength. It has been estimated that the sludge volume will increase with time because of a uranium metal → uraninite → metaschoepite oxidation sequence. This increase could increase the number of containers required for storage ...
Date: January 4, 2011
Creator: Delegard, Calvin H.; Sinkov, Sergey I.; Schmidt, Andrew J.; Daniel, Richard C. & Burns, Carolyn A.
Partner: UNT Libraries Government Documents Department

Investigations Into the Nature of Alkaline Soluble, Non-Pertechnetate Technetium

Description: This report summarizes work accomplished in fiscal year (FY) 2013, exploring the chemistry of a low-valence technetium(I) species, [Tc(CO)3(H2O)3]+, a compound of interest due to its implication in the speciation of alkaline-soluble technetium in several Hanford tank waste supernatants. Various aspects of FY 2013’s work were sponsored both by Washington River Protection Solutions and the U.S. Department of Energy’s Office of River Protection; because of this commonality, both sponsors’ work is summarized in this report. There were three tasks in this FY 2013 study. The first task involved examining the speciation of [(CO)3Tc(H2O)3]+ in alkaline solution by 99Tc nuclear magnetic resonance spectroscopy. The second task involved the purchase and installation of a microcalorimeter suitable to study the binding affinity of [(CO)3Tc(H2O)3]+ with various inorganic and organic compounds relevant to Hanford tank wastes, although the actual measure of such binding affinities is scheduled to occur in future FYs. The third task involved examining the chemical reactivity of [(CO)3Tc(H2O)3]+ as relevant to the development of a [(CO)3Tc(H2O)3]+ spectroelectrochemical sensor based on fluorescence spectroscopy.
Date: November 14, 2013
Creator: Rapko, Brian M.; Bryan, Samuel A.; Chatterjee, Sayandev; Edwards, Matthew K.; Levitskaia, Tatiana G.; Peterson, James M. et al.
Partner: UNT Libraries Government Documents Department

Sigma Team for Minor Actinide Separation: PNNL FY 2011 Status Report

Description: This report summarizes work conducted in FY 2011 at PNNL to investigate new methods of separating the minor actinide elements (Am and Cm) from the trivalent lanthanide elements, and separation of Am from Cm. For the former, work focused on a solvent extraction system combining an acidic extractant (HDEHP) with a neutral extractant (CMPO) to form a hybrid solvent extraction system referred to as TRUSPEAK (combining the TRUEX and TALSPEAK processes). For the latter, ligands that strongly bing uranyl ion were investigated for stabilizing corresponding americyl ion.
Date: August 13, 2011
Creator: Lumetta, Gregg J.; Braley, Jenifer C.; Sinkov, Sergey I.; Levitskaia, Tatiana G.; Carter, Jennifer C.; Warner, Marvin G. et al.
Partner: UNT Libraries Government Documents Department

Caustic Leaching of Hanford Tank S-110 Sludge

Description: This report describes the Hanford Tank S-110 sludge caustic leaching test conducted in FY 2001 at the Pacific Northwest National Laboratory. The data presented here can be used to develop the baseline and alternative flowsheets for pretreating Hanford tank sludge. The U.S. Department of Energy funded the work through the Efficient Separations and Processing Crosscutting Program (ESP; EM&#64979;50).
Date: October 31, 2001
Creator: Lumetta, Gregg J.; Carson, Katharine J.; Darnell, Lori P.; Greenwood, Lawrence R.; Hoopes, Francis V.; Sell, Richard L. et al.
Partner: UNT Libraries Government Documents Department

Selective Media for Actinide Collection and Pre-Concentration: Results of FY 2006 Studies

Description: In this work, we have investigated new materials for potential use in automated radiochemical separations. The work can be divided into three primary tasks: (1) synthesis of new ligands with high affinity for actinide ions, (2) evaluation of new materials for actinide ion affinity, and (3) computational design of advanced ligand architectures for highly selective binding of actinide ions. Ligand Synthesis Work was conducted on synthesizing Kl?ui ligand derivatives containing functionalized pendant groups on the cyclopentadienyl ring. The functionalized pendent groups would allow these ligands to be attached to organic and inorganic solid supports. This work focused on synthesizing the compound Na[Cp?Co(PO(OC2H5)2)3], where Cp?= C5H4C(O)OCH3. Synthesizing this compound is feasible, but the method used in FY 2006 produced an impure material. A modified synthetic scheme has been developed and will be pursued in FY 2007. Work was also initiated on synthesizing bicyclic diamides functionalized for binding to polymeric resins or other surfaces. Researchers at the University of Oregon are collaborators in this work. To date, this effort has focused on synthesizing and characterizing a symmetrically substituted bicyclic diamide ligand with the ?COOH functionality. Again, this synthetic effort will continue into FY 2007. Separations Material Evaluation Work was conducted in FY 2006 to provide a more extensive set of data on the selectivity and affinity of extraction chromatography resins prepared by sorption of Kl?ui ligand onto an inert macroreticular polymeric support. Consistent with previous observations, it was found that these materials strongly bind tetravalent actinides. These materials also adsorb trivalent actinides at low nitric acid concentrations, but the affinity for the trivalent actinides decreases with increasing nitric acid concentration. These materials have relatively low affinity for U(VI), but they do sorb U(VI) to a greater extent than Am(III) at [HNO3] &gt; 0.3 M. Preliminary results suggest that the Kl?ui resins can ...
Date: November 17, 2006
Creator: Lumetta, Gregg J.; Addleman, Raymond S.; Hay, Benjamin P.; Hubler, Timothy L.; Levitskaia, Tatiana G.; Sinkov, Sergey I. et al.
Partner: UNT Libraries Government Documents Department

Sigma Team for Minor Actinide Separation: PNNL FY 2010 Status Report

Description: Work conducted at Pacific Northwest National Laboratory (PNNL) in FY 2010 addressed two lines of inquiry. The two hypotheses put forth were: 1. The extractants from the TRUEX( ) process (CMPO)( ) and from the TALSPEAK( ) process (HDEHP)( ) can be combined into a single process solvent to separate 1) the lanthanides and actinides from acidic high-level waste and 2) the actinides from the lanthanides in a single solvent extraction process. (Note: This combined process will hereafter be referred to as the TRUSPEAK process.) A series of empirical measurements performed (both at PNNL and Argonne National Laboratory) in FY 2009 supported this hypothesis, but also indicated some nuances to the chemistry. Lanthanide/americium separation factors of 12 and higher were obtained with a prototypic TRUSPEAK solvent when extracting the lanthanides from a citrate-buffered DTPA( ) solution. Although the observed separation factors are sufficiently high to design an actinide/lanthanide separation process, a better understanding of the chemistry is expected to lead to improved solvent formulations and improved process performance. Work in FY 2010 focused on understanding the synergistic extraction behavior observed for Nd(III) and Am(III) when extracted into mixtures of CMPO and HDEHP. The interaction between CMPO and HDEHP in dodecane was investigated by 31P NMR spectroscopy, and an adduct of the type CMPO•HDEHP was found to form. The formation of this adduct will reduce the effective extractant concentrations and must be taken into account when modeling metal ion extraction data in this system. Studies were also initiated to determine the Pitzer parameters for Nd(III) in lactate media. 2. Higher oxidation states (e.g., +5 and +6) of Am can be stabilized in solution by complexation with uranophilic ligands, and this chemistry can be exploited to separate Am from Cm. To test this hypothesis, the previously reported stereognostic uranophilic ligands NPB( ) ...
Date: August 24, 2010
Creator: Lumetta, Gregg J.; Sinkov, Sergey I.; Neiner, Doinita; Levitskaia, Tatiana G.; Braley, Jenifer C.; Carter, Jennifer C. et al.
Partner: UNT Libraries Government Documents Department

Characterization, Leaching, and Filtration Testing for Bismuth Phosphate Sludge (Group 1) and Bismuth Phosphate Saltcake (Group 2) Actual Waste Sample Composites

Description: A testing program evaluating actual tank waste was developed in response to Task 4 from the M-12 External Flowsheet Review Team (EFRT) issue response plan.() The test program was subdivided into logical increments. The bulk water-insoluble solid wastes that are anticipated to be delivered to the Waste Treatment and Immobilization Plant (WTP) were identified according to type such that the actual waste testing could be targeted to the relevant categories. Eight broad waste groupings were defined. Samples available from the 222S archive were identified and obtained for testing. The actual waste-testing program included homogenizing the samples by group, characterizing the solids and aqueous phases, and performing parametric leaching tests. Two of the eight defined groups—bismuth phosphate sludge (Group 1) and bismuth phosphate saltcake (Group 2)—are the subjects of this report. The Group 1 waste was anticipated to be high in phosphorus and was implicitly assumed to be present as BiPO4 (however, results presented here indicate that the phosphate in Group 1 is actually present as amorphous iron(III) phosphate). The Group 2 waste was also anticipated to be high in phosphorus, but because of the relatively low bismuth content and higher aluminum content, it was anticipated that the Group 2 waste would contain a mixture of gibbsite, sodium phosphate, and aluminum phosphate. Thus, the focus of the Group 1 testing was on determining the behavior of P removal during caustic leaching, and the focus of the Group 2 testing was on the removal of both P and Al. The waste-type definition, archived sample conditions, homogenization activities, characterization (physical, chemical, radioisotope, and crystal habit), and caustic leaching behavior as functions of time, temperature, and hydroxide concentration are discussed in this report. Testing was conducted according to TP-RPP-WTP-467.
Date: February 19, 2009
Creator: Lumetta, Gregg J.; Buck, Edgar C.; Daniel, Richard C.; Draper, Kathryn; Edwards, Matthew K.; Fiskum, Sandra K. et al.
Partner: UNT Libraries Government Documents Department

Characterization and Leach Testing for REDOX Sludge and S-Saltcake Actual Waste Sample Composites

Description: This report describes processing and analysis results of boehmite waste type (Group 5) and insoluble high Cr waste type (Group 6). The sample selection, compositing, subdivision, physical and chemical characterization are described. Extensive batch leach testing was conducted to define kinetics and leach factors of selected analytes as functions of NaOH concentration and temperature. Testing supports issue M-12 resolution for the Waste Treatment Plant.
Date: July 10, 2008
Creator: Fiskum, Sandra K.; Buck, Edgar C.; Daniel, Richard C.; Draper, Kathryn E.; Edwards, Matthew K.; Hubler, Timothy L. et al.
Partner: UNT Libraries Government Documents Department

Development of a Chemistry-Based, Predictive Method for Determining the Amount of Non-Pertechnetate Technetium in the Hanford Tanks: FY 2012 Progress Report

Description: This report describes investigations directed toward understanding the extent of the presence of highly alkaline soluble, non-pertechnetate technetium (n-Tc) in the Hanford Tank supernatants. The goals of this report are to: a) present a review of the available literature relevant to the speciation of technetium in the Hanford tank supernatants, b) attempt to establish a chemically logical correlation between available Hanford tank measurements and the presence of supernatant soluble n-Tc, c) use existing measurement data to estimate the amount of n-Tc in the Hanford tank supernatants, and d) report on any likely, process-friendly methods to eventually sequester soluble n-Tc from Hanford tank supernatants.
Date: January 30, 2013
Creator: Rapko, Brian M.; Bryan, Samuel A.; Bryant, Janet L.; Chatterjee, Sayandev; Edwards, Matthew K.; Houchin, Joy Y. et al.
Partner: UNT Libraries Government Documents Department

Characterization Data Package for Containerized Sludge Samples Collected from Engineered Container SCS-CON-210

Description: This data package contains the K Basin sludge characterization results obtained by Pacific Northwest National Laboratory during processing and analysis of four sludge core samples collected from Engineered Container SCS-CON-210 in 2010 as requested by CH2M Hill Plateau Remediation Company. Sample processing requirements, analytes of interest, detection limits, and quality control sample requirements are defined in the KBC-33786, Rev. 2. The core processing scope included reconstitution of a sludge core sample distributed among four to six 4-L polypropylene bottles into a single container. The reconstituted core sample was then mixed and subsampled to support a variety of characterization activities. Additional core sludge subsamples were combined to prepare a container composite. The container composite was fractionated by wet sieving through a 2,000 micron mesh and a 500-micron mesh sieve. Each sieve fraction was sampled to support a suite of analyses. The core composite analysis scope included density determination, radioisotope analysis, and metals analysis, including the Waste Isolation Pilot Plant Hazardous Waste Facility Permit metals (with the exception of mercury). The container composite analysis included most of the core composite analysis scope plus particle size distribution, particle density, rheology, and crystalline phase identification. A summary of the received samples, core sample reconstitution and subsampling activities, container composite preparation and subsampling activities, physical properties, and analytical results are presented. Supporting data and documentation are provided in the appendices. There were no cases of sample or data loss and all of the available samples and data are reported as required by the Quality Assurance Project Plan/Sampling and Analysis Plan.
Date: September 10, 2013
Creator: Fountain, Matthew S.; Fiskum, Sandra K.; Baldwin, David L.; Daniel, Richard C.; Bos, Stanley J.; Burns, Carolyn A. et al.
Partner: UNT Libraries Government Documents Department