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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

Steady State Sputtering Yield and Surface Compositions of Depleted Uranium and Uranium Carbide bombarded by 16 and 30 keV Gallium or 16 keV Cesium Ions.

Depleted uranium that included carbide precipitates was sputtered with 30keV gallium ions or 16kev cesium ions to depths much greater than the ions’ range, i.e. using steady state sputtering. The recession of both the uranium’s and uranium carbide’s surfaces and the corresponding ion fluences were used to determine the steady state target sputtering yields of both uranium and uranium carbide. 6.3 and 6.02 atoms of uranium versus 2.4 and 1.45 units of uranium carbide were sputtered per gallium ion at 30 kV and 16 kV, respectively. 9.9 uranium atoms and 3.65 units of uranium carbide sputtered per cesium ion at 16 kV. The measured steady state sputtering coefficients for Ga at 30 keV and Cs at 16 keV are close to, but smaller than calculated sputtering coefficients for pure uranium. The steady state surface composition resulting from the simultaneous gallium or cesium implantation and sputter-erosion of uranium and uranium carbide were calculated to be U86Ga14, (UC) 70 Ga 30 and U 86 Ga 14 , (UC) 59 Ga 41 for Ga at 30keV and 16keV, respectively, and U 81 Cs 9 , (UC) 78 Cs 22 for Cesium at 16 keV,

36 MATERIALS SCIENCE↗
DOE OSTI2014

Steady State Sputtering Yields and Surface Compositions of Depleted Uranium and Uranium Carbide bombarded by 30 keV Gallium or 16 keV Cesium Ions.

Depleted uranium that included carbide inclusions was sputtered with 30-keV gallium ions or 16-kev cesium ions to depths much greater than the ions’ range, i.e. using steady-state sputtering. The recession of both the uranium’s and uranium carbide’s surfaces and the ion corresponding fluences were used to determine the steady-state target sputtering yields of both uranium and uranium carbide, i.e. 6.3 atoms of uranium and 2.4 units of uranium carbide eroded per gallium ion, and 9.9 uranium atoms and 3.65 units of uranium carbide eroded by cesium ions. The steady state surface composition resulting from the simultaneous gallium or cesium implantation and sputter-erosion of uranium and uranium carbide were calculated to be U₈₆Ga₁₄, (UC)₇₀Ga₃₀ and U₈₁Cs₉, (UC)₇₉Cs₂₁, respectively.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2019

ToF-SIMS Depth Profiling of Organic Delta Layers with Low-Energy Cesium Ions: Depth Resolution Assessment

The advent of cluster ion beams has paved the way to the routine 3D analysis of organic heterojunctions. Alternatively, organic thin layers have also been successfully depth profiled with a low-energy cesium ion beam (Cs{sup +}), to exploit the high chemical reactivity of cesium atoms, acting as free-radical scavengers. Despite of this, little is known about the depth resolution associated with low-energy Cs{sup +} sputtering on organic multilayers. In this work, amino acids multilayers, consisting of phenylalanine delta layers alternated with tyrosine spacers, were used as model systems to assess the depth resolution associated with 500 eV Cs{sup +} depth profiles. High yields were obtained for quasi-molecular ions from both amino acids, and no significant chemical alteration was noticed under the monoatomic bombardment. A depth resolution as low as 4 nm is demonstrated without sensible degradation on a rather long profile depth (300 nm). Limited depth resolution (> 10 nm) along with high molecular degradation was previously reported on similar systems by combining low-energy Cs{sup +} with Ga{sup +} analysis beam. The use of the Bi{sub 3}{sup +} analysis beam results in a dramatic improvement of both the characteristic molecular signal intensities and the depth resolution. Even though the analysis beam fluence is very low compared to the sputtering beam fluence, data suggest that further reducing the analysis Bi{sub 3}{sup +} fluence could improve the depth resolution by ~ 1 nm. .

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2018

Cesium Ion Exchange Using Crystalline Silicotitanate with 5.6 M Sodium Simulant

The Low-Activity Waste Pretreatment System (LAWPS) facility is planned to pretreat Hanford tank waste supernate by filtering to remove solids and processing through ion exchange columns to remove cesium. The ion exchange media is currently (since 2018) targeted to be crystalline silicotitanate (CST). This material has been produced as an engineered form (generally spherical beads) by Honeywell UOP LLC (Des Plaines, IL). Previous forms of this media have been tested in a wide array of simulants and process scales, but column breakthrough and batch contact testing to date on actual tank waste has been limited to a few tank wastes. Washington River Protection Solutions requested a series of studies to demonstrate Cs load behavior in a small column format and determine if a simple batch contact test with CST can be used to qualify tank waste supernate prior to processing it in the LAWPS. The goal of the batch contact testing is to determine if there are any issues with the tank waste that would preclude Cs removal by the ion exchanger. Testing was conducted with IONSIV TM R9140-B CST provided by Honeywell UOP in 2018 (Batch 2081000057). The CST was received in the sodium (Na) form, so no pretreatment conditioning to convert to the Na form was required. Before use in testing, the CST was passed through a #25 sieve (710-micron openings) and collected on a #60 sieve (250-micron openings) with the intent of removing any large and fine particles. Physical properties were measured on the CST including particle size distribution (d50 = 570 microns) and scanning electron micrographic examination. The CST was rinsed with water until the contact solution was visually nearly clear. The CST bed density (1.00 g/mL) and CST bed void fraction (0.656) were measured on the sieved and rinsed CST. The batch contact testing varied Cs concentration in a 5.6 M Na simple simulant solution. Testing was conducted in a liquid volume to solids mass ratio of 200. The distribution coefficient (K d ) was determined to be 770 mL/g at the Cs equilibrium condition of 8.0 μg/mL; with a bed density of 1.00 g/mL, this corresponds to a predicted 50% Cs breakthrough of 770 bed volumes (BVs). The Cs load capacity at 8.0 μg/mL equilibrium condition was determined to be 6.16 mg Cs/g dry CST. The column testing was prototypic to the intended LAWPS operations in a lead-lag column format, albeit on a small-scale basis with 10-mL CST beds. The feed was processed downflow through the lead column and then through the lag column. Three flowrates were tested: 1.19, 1.99, and 4.56 BV/h. The feed was displaced with 0.1 M NaOH, and then the columns were rinsed with water sequentially through the lead then lag columns. One column system was evaluated top to bottom with a gamma scanner to assess the axial Cs loading. Table ES.1 summarizes the relevant Cs loading characteristics.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2017

Cesium Ion Exchange Using Spherical Resorcinol-Formaldehyde Resin in Support of Waste Qualification Testing for LAWPS

The Low-Activity Waste Pretreatment System (LAWPS) facility is planned to pretreat Hanford tank waste supernate by filtering solids and processing through ion exchange columns to remove cesium. The ion exchange media is currently targeted to be spherical resorcinol-formaldehyde resin (SRF). This media has been tested in a wide array of simulants and process scales, but testing to date on actual tank waste has been limited to two tank wastes. Washington River Protection Solutions (WRPS) requested a study to determine if a simple batch contact test with SRF can be used to qualify tank waste supernate prior to processing it in the LAWPS. The goal of the batch contact testing would be to determine if there are any issues with the tank waste that would preclude Cs removal by the ion exchanger.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Small-angle neutron scattering study of specific interaction and coordination structure formed by mono-acetyl-substituted dibenzo-20-crown-6-ether and cesium ions

This study uses small-angle neutron scattering (SANS) to elucidate the coordination structure of the complex of mono-acetyl-substituted dibenzo-20-crown-6-ether (ace-DB20C6) with cesium ions (Cs + ). SANS profiles obtained for the complex of ace-DB20C6 and Cs + (ace-DB20C6/Cs) in deuterated dimethyl sulfoxide indicated that Cs + coordination resulted in a more compact structure than the free ace-DB20C6. The data were fitted well with SANS profiles calculated using Debye function for scattering on an absolute scattering intensity scale. For this theoretical calculation of the scattering profiles, the coordination structure proposed based on density functional theory calculation was used. Furthermore, we conclude that the SANS analysis experimentally supports the proposed coordination structure of ace-DB20C6/Cs and suggests the following: (1) the complex of ace-DB20C6 and Cs + is formed with an ace-DB20C6/Cs molar ratio of 1/1 and (2) the two benzene rings of ace-DB20C6 fold around Cs + above the center of the crown ether ring of ace-DB20C6.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Cesium Ion Exchange Testing Using a Three-Column System with Crystalline Silicotitanate and Hanford Tank Waste 241-AP-107

Washington River Protection Solutions (WRPS) is working to support early production of immobilized low-activity waste by feeding Hanford tank supernate from tank farms to the Hanford Waste Treatment and Immobilization Plant (WTP) Low-Activity Waste (LAW) facility. This goal incorporates the design of a Tank-Side Cesium Removal (TSCR) system, which in effect filters tank waste supernate and processes it through a cesium ion exchange medium to remove 137Cs. The 137Cs-depleted product is sent to the WTP for vitrification. Rovira et al. (2018) reported the successful Cs removal from Hanford tank 241-AP-107 waste (hereafter called AP-107) using crystalline silicotitanate (CST) ion exchange media manufactured by Honeywell UOP, LLC (product IONSIVTM R9140-B, Batch 2081000057) in a lead-lag column system. Since that testing, WRPS has changed the column design to a three-column system. WRPS requested a repeated study with AP-107 tank waste using a different batch of IONSIVTM R9140-B, Lot 2002009604, in a three-column format. A small-scale test platform was constructed to demonstrate solids filtration, Cs removal, and LAW vitrification and installed at Pacific Northwest National Laboratory. This report describes the small-scale ion exchange testing system component of the test platform and the processing of approximately 8.55 L of filtered AP-107 supernate using CST, Lot 8056262-999, that passed through a 25-mesh filter. This report also describes the Cs ion exchange batch contact testing to determine the Cs distribution coefficient and the maximum Cs loading capacity in the AP-107 tank waste matrix. Batch contact testing helps to evaluate CST performance on tank waste supernate and is often used prior to processing tank waste through ion exchange columns to assess some performance metrics (e.g., 50% Cs breakthrough). Batch contact tests were performed with the filtered AP-107 tank waste at four Cs concentrations at a phase ratio of 200 (liquid volume to exchanger mass). The distribution coefficient (K d ) at the equilibrium condition of 9.2 µg Cs/mL (AP-107 feed condition) was determined to be 806 mL AP 107/g CST. With a CST bed density of 1.01 g/mL (<25 mesh CST), this K d corresponded to a predicted 50% Cs breakthrough of 814 bed volumes (BVs). The Cs load capacity at the equilibrium feed condition was determined to be 8.3 mg Cs/g dry CST. The three-column format testing was prototypic to the intended TSCR operations, albeit on a small scale with 10-mL CST beds. Flowrate was adjusted to match the CST contact time expected for the full-scale operation, i.e., matched bed volumes per hour (BV/h) flow rate. The feed was processed downflow through the lead column, then through the middle column, and then through the polish column. Loading continued at an average of 1.88 BV/h (1.83 to 2.04 BV/h range) until the entire available AP-107 feed was processed. The Cs-decontaminated product will be provided for vitrification testing. The lead column only reached 45% Cs breakthrough after processing 855 BVs of feed. The 50% Cs breakthrough was extrapolated to occur at ~900 BVs. This extrapolated 50% Cs breakthrough value differed from the batch contact estimate (814 BVs) by 13%. The waste acceptance criteria (WAC) or contract limit for the WTP LAW vitrification facility is 3.18E-5 Ci 137 Cs per mole Na. For the AP-107 tank waste, only 0.127% of the influent 137 Cs concentration may be delivered to the WTP; this required a Cs decontamination factor of 787. The Cs effluent from the middle column reached the WAC after processing 590 BVs. Cs breakthrough from the polish column began at 590 BVs, reaching 6.3E-3 µCi/mL or 4.3E-3% Cs breakthrough after processing 844 BVs of feed.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2025

Demonstration of closed shell breeding of cesium ions with an electron beam ion source

An electron beam ion source serves as a charge breeder for the Californium Rare Isotope Breeder Upgrade (CARIBU) at the Argonne Tandem Linac Accelerator System (ATLAS). The source accepts radioactive beams of 1+ or 2+ ions and raises their charge state for post-acceleration by ATLAS. The efficiency of this process impacts the length of each experiment and, hence, the type and number of experiments that can be run in each program cycle. Recent efforts to improve the charge breeding efficiency for the 80 < A < 160 species typical of CARIBU have focused on utilizing the closed shell breeding technique. Here, with this technique, the electron beam energy is manipulated to take advantage of the large gap in ionization energies at shell closures and selectively populate a single charge state. Charge breeding studies with stable cesium ions have demonstrated an absolute efficiency of 72% for Cs 27+ and a total efficiency of 93%. The Cs 27+ efficiency result represents a factor of 3 improvement over the previous best charge breeding result of 23% for Cs 27+ .

Vondrasek, R. [Argonne National Laboratory (ANL), ↗
DOE OSTI2017

Sorption Behavior of Cesium Ions on Calcium Aluminosilicate Hydrate under the Condition Saturated with Saline Water - 17096

This study focused on the interaction of cesium (Cs) ions with calcium silicate hydrate (CSH) and calcium aluminosilicate hydrate (CASH) gel, of which sorption effect may retard the migration of Cs ions in the radioactive waste disposal system. In the sorption experiments, the influences of the Al/Si molar ratio of C(A)SH and the curing periods on the sorption of Cs ions into C(A)SH under the saline conditions were examined without drying processes by monitoring the concentrations of Cs, Ca, Si and Al. Besides, Raman spectroscopy were applied to the structure analysis of C(A)SH. As a result, the sorption of Cs ions on C(A)SH became larger with the increase in the Al/Si molar ratios under the all conditions. Furthermore, Raman spectra showed the formation of Al-tetrahedrons and Al-octahedrons, and the increase in the polymerization degree of silicate chain in CASH with adding Al. These results mean that the negative layer-charge of the sheets containing Si- and Al-tetrahedrons and Al-octahedron will accelerate the sorption of Cs ions of positive charge, electrostatically. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Cesium Ion Exchange with Crystalline Silicotitanate Literature Review

Crystalline silicotinante (CST) is planned for use as the ion exchange media to accomplish the cesium (Cs) decontamination of low-activity waste (LAW) in the current evolution of the Direct Feed Low-Activity Waste flowsheet. CST has yet to be deployed in a production-scale operating waste treatment facility on the Hanford Site. However, CST was used nearly 20 years ago to successfully treat approximately 270,000 gallons of supernatant waste in modular columns at Oak Ridge National Laboratory. As part of the technical maturation of the media for use at Hanford, an assessment of the state-of-the-art was performed by reviewing work in the technical literature. The review considered work from the U.S. Department of Energy (DOE) complex (i.e., national laboratories and government documents), the CST manufacturer, and the open technical literature nationally and internationally. The review focused on information most relevant to the caustic, high-sodium chemical environment typical of Hanford LAW. The topic areas explored in this literature review document include the following: CST structural and physical properties; Isotherm and batch contact data; Mass transport: intraparticle, interparticle, dispersion in the column; Column performance at multiple scales; Hydraulic performance; The effect of process conditions; Gas generation and retention behavior; Post-processing options for spent CST media The reviewed literature demonstrates that CST is well-suited for Cs decontamination of Hanford LAW. However, after consideration of the available literature data in these subject areas, some uncertainties regarding the application of CST for the treatment of Hanford LAW are identified and summarized. These uncertainties are areas where additional information may permit better prediction of CST performance or provide margin to facility operations and safety basis analyses.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Cesium Ion Exchange Testing Using Crystalline Silicotitanate with Hanford Tank Waste 241-AP-107 - 19104

Pacific Northwest National Laboratory has been tasked with demonstrating the unit operations for the Low-Activity Waste Pretreatment System (LAWPS) with Hanford tank waste. Washington River Protection Solutions requested that Hanford tank waste collected from tank 241-AP-107 be processed using conceived pretreatment steps (suspended solids removal by filtration, Cs removal by ion exchange), then vitrified. Bench-scale ion exchange testing with approximately 9 L of filtered AP-107 supernate was conducted using crystalline silicotitanate (CST) ion exchange media. Batch contact testing was performed to evaluate CST performance on tank waste prior to processing it in the LAWPS. Subsequently, column testing was performed using prototypic LAWPS operations in a lead-lag column arrangement using 10-mL CST beds. Loading continued until the lag column reached the Hanford Tank Waste Treatment and Immobilization Plant waste acceptance criteria (WAC) for receiving supernatant waste for vitrification (a function of the Na and {sup 137}Cs concentrations). The Cs effluent from the lag column reached the WAC after processing half the feed volume. To keep the subsequent product effluent below the WAC, a new lag column was needed to continue processing and the original lag column was moved to the lead position. Greater than 99% of the Cs processed through the ion exchange system was collected on the CST in the columns. The AP-107 feed and column processing effluent underwent extensive characterization to better define waste characteristics and assess fractionation to the CST. Selected batch contact and lead column samples were analyzed to assess selected metal analyte load characteristics. Results of these analyses will be discussed. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Cesium Ion Exchange Testing Using Crystalline Silicotitanate with Hanford Tank Waste 241-AP-107

Pacific Northwest National Laboratory has been tasked with demonstrating the unit operations for the Low Activity Waste Pretreatment System with actual Hanford tank waste. Crystalline silicotitanate (CST) ion exchange media is planned to be used to remove cesium (137Cs) from the aqueous phases of the tank wastes. Washington River Protection Solutions requested that Hanford tank waste collected from tank 241-AP-107 be processed using conceived pretreatment steps (suspended solids removal by filtration, Cs removal by ion exchange), then vitrified. Removal of Cs from these wastes is an important processing step in preparing the waste for long-term safe storage. Bench-scale ion exchange testing with approximately 9 L of filtered AP-107 supernate was conducted using CST. Column testing was performed using prototypic LAWPS operations in a lead-lag column arrangement using 10-mL CST beds. Feed was processed until the lag column effluent reached the Hanford Tank Waste Treatment and Immobilization Plant waste acceptance criteria (WAC) for receiving supernatant waste for vitrification (a function of the Na and 137Cs concentrations), at which point, a new lag column was needed to continue processing and the original lag column was moved to the lead position. Greater than 99% of the Cs processed through the ion exchange system was collected on the CST in the columns. The AP-107 feed and column processing effluent underwent extensive characterization to better define waste characteristics and assess fractionation to the CST. Selected lead column samples were analyzed to assess particular metal analyte load characteristics. Results of these analyses will be discussed.

cesium exchange, Hanford tank waste, ion exchange↗
DOE OSTI2021

Small to Full-Height Scale Comparisons of Cesium Ion Exchange Performance with Crystalline Silicotitanate

Crystalline silicotitanate (CST) ion exchanger is planned to be used to remove cesium (137Cs) from the aqueous phases of Hanford tank wastes in preparation for vitrification at the Waste Treatment and Immobilization Plant (WTP) Pretreatment Facility. Column scale up testing was conducted to evaluate performance of Cs exchange onto the CST. Batch contact testing was conducted to assess exchange kinetics of Cs exchange at four different CST PSDs. Column testing was conducted at three column sizes, small (2.5% full height), medium (12% full height), and full height, to assess Cs load performance behavior. Testing at the small scale was compared to actual Hanford tank waste testing to verify the validity of simulant tests to accurately represent full height column performance. A change in CST particle size was essential in scaling the small column dynamics up to full scale. Based on these results, a determination of intraparticle and film diffusion impacts on overall mass transfer coefficients will allow future modeling of the breakthrough performance at a range of process conditions.

Westesen, Amy M.↗
DOE OSTI2018

Multi-Cycle Cesium Ion Exchange Testing Using Spherical Resorcinol-Formaldehyde Resin with Diluted Hanford Tank Waste 241-AP-105

Washington River Protection Solutions requested that at least 4 L of Hanford tank waste collected from tank 241-AP-105 and diluted to approximately 5.6 M Na (AP-105DF) be prepared for use in vitrification studies. Cesium removal was required to meet this objective and the waste pretreatment platform, established at Pacific Northwest National Laboratory, was used to create the vitrification feed. The Test Platform mimicked the Low-Activity Waste Pretreatment System (LAWPS) facility planned to pretreat Hanford tank waste supernate by removing solids in a cross flow filter apparatus and processing the supernate through ion exchange columns to remove cesium. At the time of testing, the ion exchange media was targeted to be spherical resorcinol-formaldehyde (SRF) resin. The SRF resin has been tested with a wide array of simulants and process scales, but column performance testing with actual tank waste had been somewhat limited to two Hanford tank wastes (AP-101 and AN-102) in up to two process cycles. This report describes testing conducted in a total of six load elute cycles with the AP-105DF tank waste. The column system was first tested with simulant and was previously described; this report describes the six process cycle results with the AP-105DF tank waste.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Fundamental Study on Effects of Borate on the Sorption of Cesium ions to Calcium Silicate Hydrate - 18068

The effects of borate on the formation of calcium silicate hydrate (C-S-H) and the Cs sorption behavior were examined by the sorption experiments without drying process. C-S-H was prepared by mixing calcium oxide, fumed silica, and sodium-borate solution in a glove bag filled with nitrogen gas. The volume of sodium borate solution was 30 mL, in order to adjust the liquid/solid weight ratio to 20. The Ca/Si molar ratio of C-S-H was adjusted so as to be 0.4, 0.8, 1.2, and 1.6. The concentration of sodium borate was set to the range from 0 to 600 mM in the sample solution. The solution of cesium chloride was added to the each sample for setting the initial concentration of Cs ions to 1 mM. The samples were cured in a shaking chamber at 298 K and 120 strokes/min during 7 days. In addition, for estimating the curing-period dependencies, the curing period was set to the range from 0.5 to 28 days for the condition of 0 M or 400 M sodium borate. In the results, under the conditions of the borate concentration up to 200 mM, the sorption behavior of Cs ions to C-S-H was hardly different from those without borate, while the sorption ratio of Cs ions for the borate concentration of 400 mM or more decreased by down to 46% compared with the blank samples. However, the sorption ratio of Cs ions in the case of 400 mM borate increased and reached as much as that for the blank sample until 28 days. Besides, the Raman spectra of solid phase showed that the peak derived from boric acid or borate (calcium borate or calcium borosilicate hydrate) appeared under the high concentration conditions of borate, and the peak of the silica chain of C-S-H was weakened. Considering the practical concentration of borate and much longer period for the performance assessment of the solidified wastes, the immobilization properties for Cs ions of cementitious materials contained borate will be kept appropriately in the disposal system for low-level wastes. (authors)

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Small to Full Height Scale Comparisons of Cesium Ion Exchange Performance with Crystalline Silicotitanate

The U.S. Department of Energy’s (DOE) Hanford Site houses 56 million gallons of high-level radioactive waste generated from plutonium production from 1944 to 1988. The supernatant waste, currently stored in underground tanks, is intended to be vitrified following filtration and 137 Cs removal at the Hanford Waste Treatment and Immobilization Plant (WTP) Low-Activity Waste (LAW) Vitrification Facility. The WTP Pretreatment Facility will not be operational for several years. The Tank Side Cesium Removal (TSCR) system is a technology demonstration that will remove cesium from tank waste supernate to support directly feeding LAW to the vitrification facility. The 137 Cs removal is important to meet the WTP LAW contract specification and ultimately for creating a contact-handled waste form. The waste acceptance criteria (WAC) limit for the WTP LAW Facility is <3.18E-5 Ci 137 Cs per mole Na. The TSCR system is skid mounted and employs two key technologies: dead end filtration for solids removal and ion exchange (IX) for cesium removal. Filtration is necessary to protect the functionality of the IX columns. The IX process utilizes sodium form crystalline silicotitanate (CST) IX media produced by UOP Honeywell, LLC (Des Plaines, IL) under the product name IONSIV R9140-B, 18 x 50 mesh, in a lead-lag-polish column configuration. Each column contains a CST bed height of 92 inches and a volume of approximately 157 gallons of CST IX media. The full-scale TSCR operation will run at a residence time of 1.9 bed volumes (BV)/h, which results in a superficial velocity of 7.3 cm/min and a flowrate of ~5 gal/min. Column testing at small (2.5% of the full bed height), medium (12% of the full bed height), and full-height scales has been previously conducted to evaluate process variables and scale up performance of Cs exchange onto the CST. Cesium load performances from various sieve cuts at the small scale indicated that a 30-mesh sieve cut be tested to determine if it better reflects the 12% and full-height column performances at the small scale. Two process flowrates were tested in the small-column configuration with <30-mesh CST and simulant solutions. These tests were compared to full-height column tests at the same residence times to assess CST particle size effect on column scaling. Table S.1 summarizes the observed column performance determined for the two flowrates juxtaposed to the previous work with 5.6 M Na simulant at higher scales (used as benchmarks). The WAC breakthroughs between the small and full-height tests at 1.3 BV/h differed by ~59 BVs. The WAC breakthroughs for small, medium, and full-height tests at 1.8 BV/h were consistent at 240 BVs. The 50% Cs breakthroughs were nominally equivalent for all column tests. The common transition zones and onsets of Cs breakthrough at the 1.8 BV/h tests indicated that the Cs mass transfers were equivalent and thus the <30-mesh CST Cs load performance at the small scale successfully modeled that of the full-height system. It is recommended that the <30-mesh CST be used in subsequent 10-mL CST bed tests.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Dead-End Filtration and Crystalline Silicotitanate Cesium Ion Exchange with Hanford Tank Waste AW-102

The Direct Feed Low-Activity Waste (DFLAW) flowsheet provides for the initial production of immobilized low-activity waste (ILAW) by feeding low-activity waste (LAW) directly from tank farms to the Hanford Tank Waste Treatment and Immobilization Plant (WTP) LAW facility for immobilization. Prior to the transfer of feed to the WTP LAW facility, tank supernatant waste will be pretreated by the Tank Side Cesium Removal (TSCR) system to meet the WTP LAW waste acceptance criteria (<3.18E-5 Ci 137Cs/mole of Na). This pretreatment facility will filter the waste to remove suspended solids and remove cesium from the waste stream through ion exchange. Bench-scale filtration testing of 7.4 liters of diluted of AW-102 supernate was conducted using dead-end filtration in the hot cells of the Radiochemical Processing Laboratory at Pacific Northwest National Laboratory. A Mott 70-mm disc filter (media grade 5) was used to capture solids. The filter area was adjusted to 2.2 in2 to match the planned TSCR supernate process volume to surface area ratio. There was no indication of filter fouling and no recoverable solids were observed on the filter. Ion exchange testing with the filtered, diluted AW-102 supernatant was conducted using crystalline silicotitanate (CST) ion exchange media. The IONSIV R9140-B CST was provided by Honeywell UOP, LLC in 2018 (Lot number 8056202-999). The column testing operations were prototypic to the intended Low-Activity Waste Pretreatment System operations in a lead-lag column format, although on a small-scale basis with 10-mL CST beds. The feed was processed downflow through the lead column and then through the lag column at ~1.8 bed volumes per hour (BV/h). After 88.6 BVs of feed processing, the volume in the feed bottle dropped below the inlet tube and the lead column fluid headspace was displaced with air. Feed processing was suspended while a new column was prepared and installed into the lead position. A total of 450 BVs of diluted AW-102 feed were processed through the new lead column; only 4.3% Cs breakthrough was achieved. This volume of feed was insufficient to generate useful Cs loading information without extrapolation. A straight-line extrapolation was used to determine the 50% breakthrough of the lead column and contract limit breakthrough from the lag. The values were found to be 1200 BVs and 930 BVs, respectively.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2014

Literature Review of Spherical Resorcinol-Formaldehyde for Cesium Ion Exchange

The current report summarizes work performed throughout the scientific community and DOE complex as reported in the open literature and DOE-sponsored reports to evaluate the Cs+ ion exchange (CIX) characteristics of SRF resin. King (2007) completed a similar literature review in support of material selection for the Small Column Ion Exchange (SCIX) project. Josephson et al. (2010) and Sams et al. (2009) provided a similar brief review of SRF CIX for the near-tank Cs+ removal (NTCR) project. Thorson (2008a) documented the basis for recommending SRF over SuperLigTM 644 as the primary CIX resin in the WTP. The current review expands on previous work, summarizes additional work completed to date, and provides a broad view of the literature without focusing on a specific column system. Although the focus of the current review is the SRF resin, many cited references include multiple materials such as the non-spherical GGRF and SuperLigTM 644 organic resins and crystalline silicotitanate (CST) IONSIVTM IE-911, a non-elutable inorganic material. This report summarizes relevant information provided in the literature.

cesium removal↗