Technetium in Alkaline, High-salt, Radioactive Tank Waste Supernate

Technetium in Alkaline, High-salt, Radioactive Tank Waste Supernate PDF Author: David L. Blanchard (Jr.)
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ISBN:
Category :
Languages : en
Pages :

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Technetium in Alkaline, High-salt, Radioactive Tank Waste Supernate

Technetium in Alkaline, High-salt, Radioactive Tank Waste Supernate PDF Author: David L. Blanchard (Jr.)
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Separation, Concentration, and Immobilization of Technetium and Iodine from Alkaline Supernate Waste

Separation, Concentration, and Immobilization of Technetium and Iodine from Alkaline Supernate Waste PDF Author:
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ISBN:
Category :
Languages : en
Pages :

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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.

Science and Technology for Disposal of Radioactive Tank Wastes

Science and Technology for Disposal of Radioactive Tank Wastes PDF Author: Wallace W. Shulz
Publisher: Springer Science & Business Media
ISBN: 1489915435
Category : Technology & Engineering
Languages : en
Pages : 513

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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.

Fundamentals and Applications of Anion Separations

Fundamentals and Applications of Anion Separations PDF Author: Bruce A. Moyer
Publisher: Springer Science & Business Media
ISBN: 1441989730
Category : Science
Languages : en
Pages : 360

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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.

Aqueous Two-Phase Systems

Aqueous Two-Phase Systems PDF Author: Rajni Hatti-Kaul
Publisher: Springer Science & Business Media
ISBN: 1592590284
Category : Science
Languages : en
Pages : 442

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Book Description
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.

Developing and Testing an Alkaline-side Solvent Extraction Process for Technetium Separation from Tank Waste

Developing and Testing an Alkaline-side Solvent Extraction Process for Technetium Separation from Tank Waste PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 34

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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.

Proceedings of the International Conference on Decommissioning and Decontamination and on Nuclear and Hazardous Waste Management

Proceedings of the International Conference on Decommissioning and Decontamination and on Nuclear and Hazardous Waste Management PDF Author:
Publisher:
ISBN:
Category : Hazardous wastes
Languages : en
Pages : 804

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Preliminary Ion Exchange Modeling for Removal of Technetium from Hanford Waste Using SuperLig 639 Resin

Preliminary Ion Exchange Modeling for Removal of Technetium from Hanford Waste Using SuperLig 639 Resin PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 5

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Book Description
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.

Nuclear Waste Management

Nuclear Waste Management PDF Author: Paul W. Wang
Publisher: American Chemical Society
ISBN:
Category : Language Arts & Disciplines
Languages : en
Pages : 376

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Book Description
This symposium series book presents leading-edge research in the area of nuclear waste management conducted through the EMSP.

Radioanalytical Methods in Interdisciplinary Research

Radioanalytical Methods in Interdisciplinary Research PDF Author: Carola A. Laue
Publisher:
ISBN:
Category : Law
Languages : en
Pages : 390

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Book Description
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.