Download or read book Strontium and Actinide Separations from High Level Nuclear Waste Solutions Using Monosodium Titanate Actual Waste Testing written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Pretreatment processes at the Savannah River Site will separate 9°Sr, alpha-emitting and radionuclides (i.e., actinides) and 137Cs prior to disposal of the high-level nuclear waste. Separation of 9°Sr and alpha-emitting radionuclides occurs by ion exchange/adsorption using an inorganic material, monosodium titanate (MST). Previously reported testing with simulants indicates that the MST exhibits high selectivity for strontium and actinides in high ionic strength and strongly alkaline salt solutions. This paper provides a summary of data acquired to measure the performance of MST to remove strontium and actinides from actual waste solutions. These tests evaluated the effects of ionic strength, mixing, elevated alpha activities, and multiple contacts of the waste with MST. Tests also provided confirmation that MST performs well at much larger laboratory scales (300-700 times larger) and exhibits little affinity for desorption of strontium and plutonium during washing.
Download or read book STRONTIUM AND ACTINIDE SEPARATIONS FROM HIGH LEVEL NUCLEAR WASTE SOLUTIONS USING MONOSODIUM TITANATE 1 SIMULANT TESTING written by K. M. MARSHALL and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: High-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) requires pretreatment to remove {sup 137}Cs, {sup 90}Sr and alpha-emitting radionuclides (i.e., actinides) prior to disposal. Separation processes planned at SRS include caustic side solvent extraction, for {sup 137}Cs removal, and ion exchange/sorption of {sup 90}Sr and alpha-emitting radionuclides with an inorganic material, monosodium titanate (MST). The predominant alpha-emitting radionuclides in the highly alkaline waste solutions include plutonium isotopes {sup 238}Pu, {sup 239}Pu and {sup 240}Pu. This paper provides a summary of data acquired to measure the performance of MST to remove strontium and actinides from simulated waste solutions. These tests evaluated the influence of ionic strength, temperature, solution composition and the oxidation state of plutonium.
Download or read book Advanced Separation Techniques for Nuclear Fuel Reprocessing and Radioactive Waste Treatment written by Kenneth L Nash and published by Elsevier. This book was released on 2011-03-15 with total page 513 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced separations technology is key to closing the nuclear fuel cycle and relieving future generations from the burden of radioactive waste produced by the nuclear power industry. Nuclear fuel reprocessing techniques not only allow for recycling of useful fuel components for further power generation, but by also separating out the actinides, lanthanides and other fission products produced by the nuclear reaction, the residual radioactive waste can be minimised. Indeed, the future of the industry relies on the advancement of separation and transmutation technology to ensure environmental protection, criticality-safety and non-proliferation (i.e., security) of radioactive materials by reducing their long-term radiological hazard.Advanced separation techniques for nuclear fuel reprocessing and radioactive waste treatment provides a comprehensive and timely reference on nuclear fuel reprocessing and radioactive waste treatment. Part one covers the fundamental chemistry, engineering and safety of radioactive materials separations processes in the nuclear fuel cycle, including coverage of advanced aqueous separations engineering, as well as on-line monitoring for process control and safeguards technology. Part two critically reviews the development and application of separation and extraction processes for nuclear fuel reprocessing and radioactive waste treatment. The section includes discussions of advanced PUREX processes, the UREX+ concept, fission product separations, and combined systems for simultaneous radionuclide extraction. Part three details emerging and innovative treatment techniques, initially reviewing pyrochemical processes and engineering, highly selective compounds for solvent extraction, and developments in partitioning and transmutation processes that aim to close the nuclear fuel cycle. The book concludes with other advanced techniques such as solid phase extraction, supercritical fluid and ionic liquid extraction, and biological treatment processes.With its distinguished international team of contributors, Advanced separation techniques for nuclear fuel reprocessing and radioactive waste treatment is a standard reference for all nuclear waste management and nuclear safety professionals, radiochemists, academics and researchers in this field. - A comprehensive and timely reference on nuclear fuel reprocessing and radioactive waste treatment - Details emerging and innovative treatment techniques, reviewing pyrochemical processes and engineering, as well as highly selective compounds for solvent extraction - Discusses the development and application of separation and extraction processes for nuclear fuel reprocessing and radioactive waste treatment
Download or read book TAILORING INORGANIC SORBENTS FOR SRS STRONTIUM AND ACTINIDE SEPARATIONS written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This document provides a final report of Phase II testing activities for the development of a modified monosodium titanate (MST) that exhibits improved strontium and actinide removal characteristics compared to the baseline MST material. The activities included determining the key synthesis conditions for preparation of the modified MST, preparation of the modified MST at a larger scale by a commercial vendor, demonstration of the strontium and actinide removal characteristics with actual tank waste supernate and measurement of filtration characteristics. Key findings and conclusions include the following. Testing evaluated three synthetic methods and eleven process parameters for the optimum synthesis conditions for the preparation on an improved form of MST. We selected the post synthesis method (Method 3) for continued development based on overall sorbate removal performance. We successfully prepared three batches of the modified MST using Method 3 procedure at a 25-gram scale. The laboratory prepared modified MST exhibited increased sorption kinetics with simulated and actual waste solutions and similar filtration characteristics to the baseline MST. Characterization of the modified MST indicated that the post synthesis treatment did not significantly alter the particle size distribution, but did significantly increase the surface area and porosity compared to the original MST. Testing indicated that the modified MST exhibits reduced affinity for uranium compared to the baseline MST, reducing risk of fissile loading. Shelf-life testing indicated no change in strontium and actinide performance removal after storing the modified MST for 12-months at ambient laboratory temperature. The material releases oxygen during the synthesis and continues to offgas after the synthesis at a rapidly diminishing rate until below a measurable rate after 4 months. Optima Chemical Group LLC prepared a 15-kilogram batch of the modified MST using the post synthesis procedure (Method 3). Performance testing with simulated and actual waste solutions indicated that the material performs as well as or better than batches of modified MST prepared at the laboratory-scale. Particle size data of the vendor-prepared modified MST indicates a broader distribution centered at a larger particle size and microscopy shows more irregular particle morphology compared to the baseline MST and laboratory prepared modified MST. Stirred-cell (i.e., dead-end) filter testing revealed similar filtration rates relative to the baseline MST for both the laboratory and vendor-prepared modified MST materials. Crossflow filtration testing indicated that with MST-only slurries, the baseline MST produced between 30-100% higher flux than the vendor-prepared modified MST at lower solids loadings and comparable flux at higher solids loadings. With sludge-MST slurries, the modified MST produced 1.5-2.2 times higher flux than the baseline MST at all solids loadings. Based on these findings we conclude that the modified MST represents a much improved sorbent for the separation of strontium and actinides from alkaline waste solutions and recommend continued development of the material as a replacement for the baseline MST for waste treatment facilities at the Savannah River Site.
Download or read book TAILORING INORGANIC SORBENTS FOR SRS STRONTIUM AND ACTINIDE SEPARATIONS written by D. Hobbs and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This document provides an interim summary report of Phase II testing activities for the development of a modified monosodium titanate (MST) that exhibits improved strontium and actinide removal characteristics compared to the baseline MST materials. The activities included determining the key synthesis conditions for preparation of the modified MST, preparation of the modified MST at a larger laboratory scale, demonstration of the strontium and actinide removal characteristics with actual tank waste supernate and characterization of the modified MST. Key findings and conclusions include the following: (1) Samples of the modified MST prepared by Method 2 and Method 3 exhibited the best combination of strontium and actinide removal. (2) We selected Method 3 to scale up and test performance with actual waste solution. (3) We successfully prepared three batches of the modified MST using the Method 3 procedure at a 25-gram scale. (4) Performance tests indicated successful scale-up to the 25-gram scale with excellent performance and reproducibility among each of the three batches. For example, the plutonium decontamination factors (6-hour contact time) for the modified MST samples averaged 13 times higher than that of the baseline MST sample at half the sorbent concentration (0.2 g L{sup -1} for modified MST versus 0.4 g L{sup -1} for baseline MST). (5) Performance tests with actual waste supernate demonstrated that the modified MST exhibited better strontium and plutonium removal performance than that of the baseline MST. For example, the decontamination factors for the modified MST measured 2.6 times higher for strontium and between 5.2 to 11 times higher for plutonium compared to the baseline MST sample. The modified MST did not exhibit improved neptunium removal performance over that of the baseline MST. (6) Two strikes of the modified MST provided increased removal of strontium and actinides from actual waste compared to a single strike. The improved performance exhibited by the modified MST indicates that fewer strikes of the modified MST would be needed to successfully treat waste that contain very high activities of {sup 90}Sr and alpha-emitting radionuclides compared to the baseline MST. (7) Reuse tests with actual waste confirmed that partially loaded MST exhibits reduced removal of strontium and actinides when contacted with fresh waste. (8) Samples of modified MST prepared by Method 3 and the baseline MST exhibited very similar particle size distributions. (9) Dead-end filtration tests showed that the modified MST samples exhibited similar filtration characteristics as the baseline MST sample. (10) Performance testing indicated no change in strontium and neptunium removal after storing the modified MST for 6-months at ambient temperature. The results suggested that plutonium removal performance may be decreased slightly after 6-months of storage. However, the change in plutonium removal is not statistically significant at the 95% confidence limit. Based on these findings we recommend continued development of the modified MST as a replacement for the baseline MST for waste treatment facilities at the Savannah River Site.
Download or read book Development of an Improved Titanate Based Sorbent for Strontium and Actinide Separations Under Strongly Alkaline Conditions written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: High-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) requires pretreatment to remove {sup 134,137}Cs, 9°Sr, and alpha-emitting radionuclides (i.e., actinides) prior to disposal onsite as low level waste. Separation processes at SRS include the sorption of 9°Sr and alpha-emitting radionuclides onto monosodium titanate (MST) and caustic side solvent extraction of 137Cs. The MST and separated 137Cs is encapsulated along with the sludge fraction of high-level waste (HLW) into a borosilicate glass waste form for eventual entombment at a federal repository. The predominant alpha-emitting radionuclides in the highly alkaline waste solutions include plutonium isotopes 238Pu, 239Pu, and 24°Pu; 237Np; and uranium isotopes, 235U and 238U. This paper describes recent results evaluating the performance of an improved sodium titanate material that exhibits increased removal kinetics and capacity for 9°Sr and alpha-emitting radionuclides compared to the current baseline material, MST.
Download or read book Evaluation of New Inorganic Sorbents for Strontium and Actinide Removal from High Level Nuclear Waste Solutions written by and published by . This book was released on 2004 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Monosodium titanate (MST), a hydrous metal oxide sorbent, is the baseline material for the removal of 90Sr and alpha-emitting radionuclides (principally 238Pu, 239Pu, 240Pu and 237Np) from alkaline waste solutions generated during the processing of irradiated nuclear materials at the Savannah River Site. This material exhibits excellent performance characteristics for strontium removal. Plutonium removal is also good, but problematic at the estimated bonding concentration. We are currently developing new inorganic materials for improved sorption characteristics. These materials include sodium nonatitanates, pharmacosiderites and heteropolyniobates. We will present results evaluating the performance of these materials with simulated and actual high level nuclear waste solutions.
Download or read book TAILORING INORGANIC SORBENTS FOR SRS STRONTIUM AND ACTINIDE SEPARATIONS written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This document provides a final report of Phase III testing activities for the development of modified monosodium titanate (mMST), which exhibits improved strontium and actinide removal characteristics compared to the baseline MST material. The activities included characterization of the crystalline phases present at varying temperatures, solids settling characteristics, quantification of the peroxide content; evaluation of the post-synthesis gas release under different conditions; the extent of desorption of 85Sr, Np, and Pu under washing conditions; and the effects of age and radiation on the performance of the mMST. Key findings and conclusions include the following. The peroxide content of several mMST samples was determined using iodometric titration. The peroxide content was found to decrease with age or upon extended exposure to elevated temperature. A loss of peroxide was also measured after exposure of the material to an alkaline salt solution similar in composition to the simulated waste solution. To determine if the loss of peroxide with age affects the performance of the material, Sr and actinide removal tests were conducted with samples of varying age. The oldest sample (4 years and 8 months) did show lower Sr and Pu removal performance. When compared to the youngest sample tested (1 month), the oldest sample retained only 15% of the DF for Pu. Previous testing with this sample indicated no decrease in Pu removal performance up to an age of 30 months. No loss in Np removal performance was observed for any of the aged samples, and no uptake of uranium occurred at the typical sorbent loading of 0.2 g/L. Additional testing with a uranium only simulant and higher mMST loading (3.0 g/L) indicated a 10% increase of uranium uptake for a sample aged 3 years and 8 months when compared to the results of the same sample measured at an age of 1 year and 5 months. Performance testing with both baseline-MST and mMST that had been irradiated in a gamma source to a total dose of 3.95 x 106 R, indicated little to no affect on the performance of the material to remove Sr and actinides. Previous testing established that mMST releases oxygen gas during the synthesis, and continues to off-gas during storage post synthesis. The post-synthesis gas release rate was measured under several conditions, including varying the pH of the wash water and at elevated temperature (49 C, typical of bounding summertime storage without air conditioning). Results indicated that a high pH (basic) wash reduced the initial gas release rate, but after 2 days the release rates from all different pH washed samples were not statistically different. The gas release rate at 49 C, a temperature at which the material may be exposed to during shipping and storage, was consistently about 2.5 times higher than the rate at room temperature. All gas release results indicated that vented containers would be necessary for shipping and storage of large quantities of material. Suspension of sorbate-loaded solids into diluted solutions representing intermediate and final stages of washing for 24-hours revealed no evidence of desorption of Sr, Pu or Np from the mMST solids. Based on the results of the Phase III testing as well as that from earlier studies (Phases I and II), SRNL researchers recommend adopting the use of the mMST material for the removal of strontium and actinides from the SRS HLW supernatant liquids in the Actinide Removal Process and Salt Waste Processing Facility. Given the decrease in Sr and Pu removal performance for the mMST having an age of 4 years and 8 months, we recommend that mMST be used within 30 months of production. Furthermore we recommend that DOE provide funding to conduct pilot-scale testing of the mixing and settling characteristics of the mMST and impact, if any, on the generation of hydrogen during processing in the Defense Waste Processing Facility (DWPF).
Download or read book CHARACTERIZATION OF MODIFIED MONOSODIUM TITANATE AN IMPROVED SORBENT FOR STRONTIUM AND ACTINIDE SEPARATIONS written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: High-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) requires pretreatment to remove {sup 134,137}Cs, 9°Sr, and alpha-emitting radionuclides (i.e., actinides) prior to disposal onsite as low level waste. An inorganic sorbent, monosodium titanate (MST), is currently used to remove 9°Sr and alpha-emitting radionuclides, while a caustic-side solvent extraction process is used for removing {sup 134,137}Cs. A new peroxotitanate material, modified MST, or mMST, has recently been developed and has shown increased removal kinetics and capacity for 9°Sr and alpha-emitting radionuclides compared to the current baseline material, MST. This paper describes recent results focused on further characterization of this material.
Download or read book Strontium and Actinides Removal from Savannah River Site Actual Waste Samples by Freshly Precipitated Manganese Oxide written by M. J. Barnes and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors investigated the performance of freshly precipitated manganese oxide and monosodium titanate (MST) for the removal of strontium (Sr) and actinides from actual high-level waste. Manganese oxide precipitation occurs upon addition of a reductant such as formate (HCO2- ) or peroxide (H2O2) to a waste solution containing permanganate (MnO4- ). Tests described in this document address the capability of manganese oxide treatment to remove Rs, Pu, and Np from actual high-level waste containing elevated concentrations of Pu. Additionally, tests investigate MST (using two unique batches) performance with the same waste for direct comparison to the manganese oxide performance.
Download or read book Mechanisms of Strontium and Uranium Removal From Radioactive Waste Simulant Solutions by the Sorbent Monosodium Titanate written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: High-Level Radioactive Waste (HLW) is the priority problem for the U.S. Dept. of Energy's Environmental Management Program. Current HLW treatment processes at the Savannah River Site (Aiken, SC) include the use of monosodium titanate (MST, similar to NaTi2O5xH2O) to concentrate radioactive strontium (Sr) and actinides. Mechanistic information about radionuclide uptake will provide us with insight about the reliability of MST treatments. We characterized the morphology of MST and the chemistry of sorbed Sr{sup 2+} and uranium [U(VI)] on MST with x-ray based spectroscopic and electron microscopic techniques. Sorbed Sr{sup 2+} exhibited specific adsorption as partially-hydrated species, whereas sorbed U exhibited site-specific adsorption as monomeric and dimeric U(VI)-carbonate complexes. These differences in site specificity and mechanism may account for the difficulties associated with predicting MST loading and removal kinetics.
Download or read book REVIEW OF EXPERIMENTAL STUDIES INVESTIGATING THE RATE OF STRONTIUM AND ACTINIDE ADSORPTION BY MONOSODIUM TITANATE written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A number of laboratory studies have been conducted to determine the influence of mixing and mixing intensity, solution ionic strength, initial sorbate concentrations, temperature, and monosodium titanate (MST) concentration on the rates of sorbate removal by MST in high-level nuclear waste solutions. Of these parameters, initial sorbate concentrations, ionic strength, and MST concentration have the greater impact on sorbate removal rates. The lack of a significant influence of mixing and mixing intensity on sorbate removal rates indicates that bulk solution transport is not the rate controlling step in the removal of strontium and actinides over the range of conditions and laboratory-scales investigated. However, bulk solution transport may be a significant parameter upon use of MST in a 1.3 million-gallon waste tank such as that planned for the Small Column Ion Exchange (SCIX) program. Thus, Savannah River National Laboratory (SRNL) recommends completing the experiments in progress to determine if mixing intensity influences sorption rates under conditions appropriate for this program. Adsorption models have been developed from these experimental studies that allow prediction of strontium (Sr), plutonium (Pu), neptunium (Np) and uranium (U) concentrations as a function of contact time with MST. Fairly good agreement has been observed between the predicted and measured sorbate concentrations in the laboratory-scale experiments.
Download or read book Chemical Separation Technologies and Related Methods of Nuclear Waste Management written by Gregory R. Choppin and published by Springer Science & Business Media. This book was released on 1999-02-28 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Separation technologies are of crucial importance to the goal of significantly reducing the volume of high-level nuclear waste, thereby reducing the long-term health risks to mankind. International co-operation, including the sharing of concepts and methods, as well as technology transfer, is essential in accelerating research and development in the field. The writers of this book are all internationally recognised experts in the field of separation technology, well qualified to assess and criticize the current state of separation research as well as to identify future opportunities for the application of separation technologies to the solution of nuclear waste management problems. The major emphases in the book are research opportunities in the utilization of innovative and potentially more efficient and cost effective processes for waste processing/treatment, actinide speciation/separation methods, technological processing, and environmental restoration.
Download or read book Mechanisms of Strontium and Uranium Removal from High Level Radioactive Waste Simulant Solutions by the Sorbent Monosodium Titanate written by and published by . This book was released on 2003 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-Level Waste (HLW) is a waste associated with the dissolution of spent nuclear fuel for the recovery of weapons-grade material. It is the priority problem for the U.S. Department of Energy's Environmental Management Program. Current HLW treatment processes at the Savannah River Site (Aiken, SC) include the use of monosodium titanate. The local structural speciation of sorbed U varied with loading but not for Sr. Sorbed Sr exhibited specific adsorption as partially-hydrated species whereas sorbed U exhibited specific adsorption as monomeric and dimeric U(VI)-carbonate complexes. Sorption proved site specific. These differences in site specificity and sorption mechanism may account for the difficulties associated with predicting Sr and U loading and removal kinetics using MST.
Download or read book Demonstration of MST and Permanganate Efficiency on Removal of Actinides and Strontium from Savannah River Site High Level Waste written by T. B. Peters and published by . This book was released on 2003 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We conducted a series of four demonstrations to determine the ability of either monosodium titanate (MST) or permanganate (MnO4- ) to remove strontium and actinides from salt solutions, under a variety of conditions. Each of the demonstrations used material derived from actual tank waste. The demonstrations used volumes as large as 68 L compared to typical prior experiments at 100 mL. Also, the study used, in two experiments, hydraulically scaled mixing conditions to match those of the equipment installed in Building 512-S for the Actinide Removal Process. (Plans call for radioactive commissioning of that facility as early as December 2003.).
Download or read book In Situ Removal of Actinides and Strontium from High Level Waste Tanks Tea Bag Versus Adsorption Column written by CROWDER. MARK and published by . This book was released on 2004 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Initiatives are underway at the Savannah River Site (SRS) to accelerate the disposition of the supernate and salt portions of the waste in the SRS High Level Waste (HLW) tank farm system. Significant savings in processing time and overall cost could be achieved by in situ treatment of waste supernate or dissolved salt inside a tank farm waste tank. For treatment of actinides and strontium in waste, the baseline method is sorption onto monosodium titanate (MST), an engineered powder with mean particle size of approximately 10 microns. In a separate study at the Savannah River National Laboratory (SRNL), engineered forms of MST were developed and compared on a small (250-mL) scale in batch tests. In the current study, a promising form of engineered MST was tested under two conditions: a traditional ion exchange (or adsorption) column and a porous, flow through device called a tea bag, immersed in solution. Both tests used the same amount of engineered MST to treat 10 L of simulated waste solution containing plutonium and strontium.
Download or read book MONOSODIUM TITANATE MULTI STRIKE TESTING written by and published by . This book was released on 2004 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research over the past decade has studied the adsorption of plutonium and uranium onto monosodium titanate (MST) in alkaline solutions. Tests showed that MST would remove the targeted radionuclides from simulated alkaline waste. Testing also indicated that Pu removal kinetics and Np capacity of the MST material impacts the size of equipment and waste blending plans for the Salt Waste Processing Facility (SWPF). Additionally, calculations suggested the baseline MST process may not achieve the desired decontamination in wastes containing elevated concentrations of Pu and Np. In this task, the authors investigated the performance of non-baseline process parameters and their effectiveness for treating waste feed in the Salt Waste Processing Facility. The work addresses a DOE request in support of technical needs expressed, in part, by the Engineering, Procurement, and Construction Contractors for the Salt Waste Processing Facility. The work investigated the effect of increased MST addition (up to 1.2 g/L) and the benefit of extra filtration steps with multiple additions of MST to salt waste containing actinides and strontium. Both simulant and actual waste testing occurred. Actual waste tests used a Tank 39H composite waste solution. In addition, testing to determine desorption of actinides from residual MST occurred. The release of sorbed Sr and actinides from loaded MST during the washing stages in the Salt Waste Processing Facility is an unresolved process behavior. Desorption tests assessed this potential problem using loaded MST from the residue of the MST adsorption tests. Analysis of non-radioactive Sr in the tests proved difficult due to the low concentration of nonradioactive Sr and its nearness to the method detection limit for ICP-MS. Efforts to use AMP to minimize dilution of actual waste for removal from the cell did not help for this analysis since instrument dilution still proved necessary due to the salt content.
