Download or read book Technetium in Alkaline High salt Radioactive Tank Waste Supernate written by David L. Blanchard (Jr.) and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Separation Concentration and Immobilization of Technetium and Iodine from Alkaline Supernate Waste written by and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Development of remediation technologies for the characterization, retrieval, treatment, concentration, and final disposal of radioactive and chemical tank waste stored within the Department of Energy (DOE) complex represents an enormous scientific and technological challenge. A combined total of over 90 million gallons of high-level waste (HLW) and low-level waste (LLW) are stored in 335 underground storage tanks at four different DOE sites. Roughly 98% of this waste is highly alkaline in nature and contains high concentrations of nitrate and nitrite salts along with lesser concentrations of other salts. The primary waste forms are sludge, saltcake, and liquid supernatant with the bulk of the radioactivity contained in the sludge, making it the largest source of HLW. The saltcake (liquid waste with most of the water removed) and liquid supernatant consist mainly of sodium nitrate and sodium hydroxide salts. The main radioactive constituent in the alkaline supernatant is cesium-137, but strontium-90, technetium-99, and transuranic nuclides are also present in varying concentrations. Reduction of the radioactivity below Nuclear Regulatory Commission (NRC) limits would allow the bulk of the waste to be disposed of as LLW. Because of the long half-life of technetium-99 (2.1 x 10 5 y) and the mobility of the pertechnetate ion (TcO 4 - ) in the environment, it is expected that technetium will have to be removed from the Hanford wastes prior to disposal as LLW. Also, for some of the wastes, some level of technetium removal will be required to meet LLW criteria for radioactive content. Therefore, DOE has identified a need to develop technologies for the separation and concentration of technetium-99 from LLW streams. Eichrom has responded to this DOE-identified need by demonstrating a complete flowsheet for the separation, concentration, and immobilization of technetium (and iodine) from alkaline supernatant waste.

Download or read book Science and Technology for Disposal of Radioactive Tank Wastes written by Wallace W. Shulz and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 513 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radioactive wastes resulting from over 40 years of production of nuclear weapons in the U. S. are currently stored in 273 underground tanks at the U. S. Department of Energy Hanford site, Idaho National Engineering and Environmental Laboratory, Oak Ridge Reservation, and Savannah River site. Combined, tanks at these sjtes contain approximately 94,000,000 gallons of waste in a variety of forms including liquid, concrete-like salt cake, and various sludges. More than 730,000,000 curies of several radioactive isotopes are present in the underground tanks. Certainly, one of the greatest challenges facing the U. S. Department of Energy is how to characterize, retrieve, treat, and immobilize the great variety of tank wastes in a safe, timely, and cost-effective manner. For several years now, the U. S. Department of Energy has initiated and sponsored scientific and engineering studies, tests, and demonstrations to develop the myriad of technologies required to dispose of the radioactive tank wastes. In recent times, much of the Department of Energy R&D activities concerning tank wastes have been closely coordinated and organized through the Tanks Focus Area (IF A); responsibility for technical operations of the TF A has been assigned to the Pacific Northwest National Laboratory.

Download or read book Fundamentals and Applications of Anion Separations written by Bruce A. Moyer and published by Springer Science & Business Media. This book was released on 2011-06-27 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book documents the proceedings of the symposium "Fundamentals and Applications of Anion Separations" held during American Chemical Society National Meeting in Chicago, Illinois, August 25-30, 200I. Nearly 40 papers devoted to discussions on anion separation related to fundamental research and applications were presented. The symposium, sponsored by Osram Sylvania, BetzDearbom, and the Separation Science & Technology Subdivision of the Industrial & Engineering Chemistry Division of the American Chemical Society was organized by Bruce A. Moyer, Chemical Sciences Division, Oak Ridge National Laboratory, P.O. Box 2008, Building. 4500S, Oak Ridge, TN 37831-6119, and Raj P. Singh, Chemicals and Powders R&D, Osram Sylvania, Chemical and Metallurgical Products Division, Towanda, PA 18848. It drew presenters from Australia, the Czech Republic, France, Germany, Japan, South Africa, Thailand, the United Kingdom, and the United States. Separations constitute an integral part of chemical industry. Chemical products typically originate in resources that must be concentrated and purified, chemically transformed, and subjected to fmal purification. Effluent streams from the processes must be treated to recycle reusable components and to remove environmentally harmful species. Some industrial processes are devoted to environmental cleanup after pollution has occurred. In addition, many analytical methods require a separation for preconcentration, or a separation may be an inherent part of the analysis itself. Micro separations occurring at membranes or interfaces are also related phenomena employed for ion sensing. Many species targeted for separation are naturally anionic. Although the standard separations techniques ofextraction, ion exchange, adsorption, precipitation, etc.

Download or read book Aqueous Two Phase Systems written by Rajni Hatti-Kaul and published by Springer Science & Business Media. This book was released on 2008-02-05 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt: A mixture of two polymers, or one polymer and a salt, in an aqueous medium separates into two phases: this phenomenon is useful in biotechn- ogy for product separations. Separation of biological molecules and particles in these aqueous two-phase systems (ATPS) was initiated over 40 years ago by P.-Å. Albertsson, and later proved to be of immense utility in biochemical and cell biological research. A boost in the application of ATPS was seen when problems of separations in biotechnology processes were encountered. Its simplicity, biocompatibility, and amenability to easy scaleup operations make the use of ATPS very attractive for large-scale bioseparations. Despite the advantages ATPS enjoys over other separation techniques, the application of two-phase systems has for a long time been confined to selected labora- ries. Recent years have, however, shown a trend in which increasing numbers of researchers employ two-phase partitioning techniques in both basic and applied research.

Download or read book Developing and Testing an Alkaline side Solvent Extraction Process for Technetium Separation from Tank Waste written by and published by . This book was released on 1997 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Engineering development and testing of the SRTALK solvent extraction process are discussed in this paper. This process provides a way to carry out alkaline-side removal and recovery of technetium in the form of pertechnetate anion from nuclear waste tanks within the DOE complex. The SRTALK extractant consists of a crown ether, bis-4,4'(5')[(tert-butyl)cyclohexano] -18-crown-6, in a modifier, tributyl phosphate, and a diluent, Isopar{reg_sign}L. The SRTALK flowsheet given here separates technetium from the waste and concentrates it by a factor often to minimize the load on the downstream evaporator for the technetium effluent. In this work, we initially generated and correlated the technetium extraction data, measured the dispersion number for various processing conditions, and determined hydraulic performance in a single-stage 2-cm centrifugal contactor. Then we used extraction-factor analysis, single-stage contactor tests, and stage-to-stage process calculations to develop a SRTALK flowsheet. Key features of the flowsheet are (1) a low organic-to-aqueous (O/A) flow ratio in the extraction section and a high O/A flow ratio in the strip section concentrate the technetium and (2) the use of a scrub section to reduce the salt load in the concentrated technetium effluent. Finally, the SRTALK process was evaluated in a multistage test using a synthetic tank waste. This test was very successful. Initial tests with actual waste from the Hanford nuclear waste tanks show the same technetium extractability as determined with the synthetic waste feed. Therefore, technetium removal from actual tank wastes should also work well using the SRTALK process.

Download or read book Proceedings of the International Conference on Decommissioning and Decontamination and on Nuclear and Hazardous Waste Management written by and published by . This book was released on 1998 with total page 804 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Preliminary Ion Exchange Modeling for Removal of Technetium from Hanford Waste Using SuperLig 639 Resin written by and published by . This book was released on 2000 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: A proposed facility is being designed for the immobilization of Hanford underground storage tank radioactive waste. The waste is pretreated to split it into Low Activity Waste (LAW) and High Level Waste (HLW) streams for separate vitrification. One unit process in the facility is designed to remove radioactive technetium by ion-exchange from a highly alkaline aqueous phase.

Download or read book Nuclear Waste Management written by Paul W. Wang and published by American Chemical Society. This book was released on 2006 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: This symposium series book presents leading-edge research in the area of nuclear waste management conducted through the EMSP.

Download or read book Radioanalytical Methods in Interdisciplinary Research written by Carola A. Laue and published by . This book was released on 2004 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses the applications of radioanalytical chemistry across a wide spectrum of interdisciplinary science and technology. This book also explores the history of the field, current trends, and future directions.

Download or read book Removal of Technetium from Alkaline Nuclear waste Media by a Solvent extraction Process Using Crown Ethers written by and published by . This book was released on 1995 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Crown ethers dissolved in suitably modified aliphatic kerosene diluents can be employed to extract technetium as pertechnetate anion (TcO4−) with good extraction ratios from realistic simulants of radioactive alkaline nitrate waste. The modifiers utilized are non-halogenated and non-volatile, and the technetium can be removed from the solvent by stripping using water. The crown ethers bis-4,4(prime)(5(prime))[(tert-butyl)cyclohexano]-18-crown-6 (di-t-BuCH18C6) and dicyclohexano-18-crown-6 (DCH18C6) provide stronger TcO4− extraction than dicyclohexano-21-crown-7 and 4-tert-butylcyclohexano 15-crown-5. Whereas DCH18C6 provides somewhat higher TcO4− extraction ratios than the more lipophilic di-t-BuCH18C6 derivative, the latter was selected for further study owing to its lower distribution to the aqueous phase. Particularly good extraction and stripping results were obtained with di-t-BuCH 18C6 at 0.02 M in a 2:1 vol/vol blend of tributyl phosphate and Isopar{reg_sign} M. Using this solvent, 98.9% of the technetium contained (at 6 x 10−5 M) in a Double-Shell Slurry Feed (DSSF) Hanford tank waste simulant was removed following two cross-current extraction contacts. Two cross-current stripping contacts with deionized water afforded removal of 99.1% of the technetium from the organic solvent.

Download or read book Characterization Of Supernate Samples From High Level Waste Tanks 13H 30H 37H 39H 45F 46F and 49H written by and published by . This book was released on 2005 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: This document presents work conducted in support of technical needs expressed, in part, by the Engineering, Procurement, and Construction Contractor for the Salt Waste Processing Facility (SWPF). The Department of Energy (DOE) requested that Savannah River National Laboratory (SRNL) analyze and characterize supernate waste from seven selected High Level Waste (HLW) tanks to allow: classification of feed to be sent to the SWPF; verification that SWPF processes will be able to meet Saltstone Waste Acceptance Criteria (WAC); and updating of the Waste Characterization System (WCS) database. This document provides characterization data of samples obtained from Tanks 13H, 30H, 37H, 39H, 45F, 46F, and 49H and discusses results. Characterization of the waste tank samples involved several treatments and analysis at various stages of sample processing. These analytical stages included as-received liquid, post-dilution to 6.44 M sodium (target), post-acid digestion, post-filtration (at 3 filtration pore sizes), and after cesium removal using ammonium molybdophosphate (AMP). All tanks will require cesium removal as well as treatment with Monosodium Titanate (MST) for 9°Sr (Strontium) decontamination. A small filtration effect for 90Sr was observed for six of the seven tank wastes. No filtration effects were observed for Pu (Plutonium), Np (Neptunium), U (Uranium), or Tc (Technetium); 137Cs (Cesium) concentration is ~E+09 pCi/mL for all the tank wastes. Tank 37H is significantly higher in 9°Sr than the other six tanks. 237Np in the F-area tanks (45F and 46F) are at least 1 order of magnitude less than the H-Area tank wastes. The data indicate a constant ratio of 99Tc to Cs in the seven tank wastes. This indicates the Tc remains largely soluble in Savannah River Site (SRS) waste and partitions similarly with Cs. 241Am (Americium) concentration was low in the seven tank wastes. The majority of data were detection limit values, the largest being

Download or read book Ion Recognition Approach to Volume Reduction of Alkaline Tank Waste by Separation of Sodium Salts written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall goal of this research conducted under the auspices of the USDOE Environmental Management Science Program (EMSP) is to provide a scientific foundation upon which the feasibility of new liquid-liquid extraction chemistry applicable to the bulk reduction of the volume of tank waste can be evaluated. Disposal of high-level nuclear waste is horrendously expensive, in large part because the actual radioactive matter in the tanks has been diluted over 10,000-fold by ordinary inorganic chemicals. Quite simply, if the radioactive matter and bulk inorganic chemicals could be separated into separate streams, large cost savings would accrue, because the latter stream is much cheaper to dispose of. In principle, one could remove the radionuclides from the waste, leaving behind the bulk of the waste; or one could remove certain bulk chemicals from the waste, leaving behind the radionuclides. The preponderance of effort over the past two decades has focused on the former approach, which produces a high-level stream for vitrification and a low-activity stream for either vitrification (Hanford) or grout (Savannah River). At Hanford, a particular concern arises in that vitrification of a large volume of low-activity waste will be unacceptably expensive. To make matters worse, a projected future deficit of tank space may necessitate construction of expensive new tanks. These problems have raised questions as to whether a solution could be devised based on separation of sodium from the waste, resulting in the reduction of the total volume of waste that must be vitrified.

Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1975 with total page 808 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Selected Annotated Bibliography of Studies Relevant to the Isolation of Nuclear Wastes written by and published by . This book was released on 1980 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chemical Precipitation Processes for the Treatment of Aqueous Radioactive Waste written by and published by . This book was released on 1992 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this report is to provide a review of chemical precipitation processes for the treatment of low and intermediate level aqueous waste. It supersedes Technical Reports Series No. 89, Chemical Treatment of Radioactive Wastes, published in 1968. It provides data on the performance of existing plants and on improved processes that are in an advanced state of development.

Download or read book Application of Ion Exchange Processes for the Treatment of Radioactive Waste and Management of Spent Ion Exchangers written by and published by . This book was released on 2002 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ion exchange is one of the most common and effective treatment methods for liquid radioactive waste. This book reviews the current literature on the subject and reports on the existing state of the art of the application of ion exchange processes for liquid radioactive waste treatments and of the management of spent ion exchange media.